NWPX / NWPX Infrastructure, Inc. - Pengajuan SECLaporan Tahunan, Pernyataan Proksi

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 OR 15(d) of The Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): August 13, 2025 NWPX Infrastructu

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 OR 15(d) of The Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): August 13, 2025 NWPX Infrastructure, Inc. (Exact name of registrant as specified in its charter) Oregon 0-27140 93-0557988 (State or other jurisdiction of incorporation) (Commission F

FOURTH AMENDMENT TO CREDIT AGREEMENT AND RATIFICATION OF LOAN DOCUMENTS

Exhibit 10.1 FOURTH AMENDMENT TO CREDIT AGREEMENT AND RATIFICATION OF LOAN DOCUMENTS This FOURTH AMENDMENT TO CREDIT AGREEMENT AND RATIFICATION OF LOAN DOCUMENTS, dated as of August 13, 2025 (this “Amendment”), is by and among NWPX INFRASTRUCTURE, INC. (F/K/A NORTHWEST PIPE COMPANY), an Oregon corporation (“Administrative Borrower”), NWPC, LLC, a Delaware limited liability company (“NWPC”), GENEVA

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-Q

Table of Contents UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-Q ☒ QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the quarterly period ended: June 30, 2025 or ☐ TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period from to Commission File Number: 0-27140 NWPX

NWPX Infrastructure, Inc. Announces Second Quarter 2025 Financial Results

Exhibit 99.1 NWPX Infrastructure, Inc. Announces Second Quarter 2025 Financial Results • Net sales of $133.2 million, a Company record under its current operating segments, increased 2.8% year-over-year • Record net sales of $48.6 million for the Precast Infrastructure and Engineered Systems segment (“Precast”) • Net income of $0.91 per diluted share • Backlog1 of $298 million for the Water Transm

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 OR 15(d) of The Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): August 7, 2025 NWPX Infrastructur

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 OR 15(d) of The Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): August 7, 2025 NWPX Infrastructure, Inc. (Exact name of registrant as specified in its charter) Oregon 0-27140 93-0557988 (State or other jurisdiction of incorporation) (Commission Fi

Amendment to Amended and Restated Bylaws

Exhibit 3.2 AMENDMENT TO AMENDED AND RESTATED BYLAWS OF NORTHWEST PIPE COMPANY (Adopted June 12, 2025) On June 12, 2025, upon the recommendation of the Board of Directors, the shareholders of Northwest Pipe Company, an Oregon corporation (the “Company”) approved an amendment to its Articles of Incorporation, as amended and restated, to change the Company’s name to NWPX Infrastructure, Inc. Such Am

Second Amendment to Second Restated Articles of Incorporation

Exhibit 3.1

Amendments to Articles of Incorporation or Bylaws; Change in Fiscal Year, Financial Statements and Exhibits, Submission of Matters to a Vote of Security Holders

-12-31 UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 OR 15(d) of The Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): June 12, 2025 NWPX Infrastructure, Inc. (Exact name of registrant as specified in its charter) Oregon 0-27140 93-0557988 (State or other jurisdiction of incorporation) (Commiss

99.1 2025 Annual Shareholder Meeting Presentation dated June 12, 2025

Exhibit 99.1

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 OR 15(d) of The Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): June 12, 2025 NORTHWEST PIPE COMP

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 OR 15(d) of The Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): June 12, 2025 NORTHWEST PIPE COMPANY (Exact name of registrant as specified in its charter) Oregon 0-27140 93-0557988 (State or other jurisdiction of incorporation) (Commission File N

16.1 Letter from Moss Adams LLP to the Securities and Exchange Commission dated June 3, 2025

Exhibit 16.1 June 3, 2025 U.S. Securities and Exchange Commission 100 F Street, NE Washington, DC 20549 Ladies and Gentlemen: We have read the statements made by the Northwest Pipe Company included under Item 4.01 of its Current Report on Form 8‑K dated June 3, 2025 to be filed with the Securities and Exchange Commission. We agree with the statements concerning our Firm contained therein. Sincerel

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 OR 15(d) of The Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): June 3, 2025 NORTHWEST PIPE COMPA

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 OR 15(d) of The Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): June 3, 2025 NORTHWEST PIPE COMPANY (Exact name of registrant as specified in its charter) Oregon 0-27140 93-0557988 (State or other jurisdiction of incorporation) (Commission File Nu

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM SD SPECIALIZED DISCLOSURE REPORT NORTHWEST PIPE COMPANY (Exact name of registrant as specified in its charter)

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM SD SPECIALIZED DISCLOSURE REPORT NORTHWEST PIPE COMPANY (Exact name of registrant as specified in its charter) Oregon 0-27140 93-0557988 (State or other jurisdiction of incorporation or organization) (Commission File Number) (I.R.S. Employer Identification No.) 201 NE Park Plaza Drive, Suite 100 Vancouver, WA 98684 (Addre

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-Q

Table of Contents UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-Q ☒ QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the quarterly period ended: March 31, 2025 or ☐ TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period from to Commission File Number: 0-27140 NOR

Northwest Pipe Company Announces First Quarter 2025 Financial Results

Exhibit 99.1 Northwest Pipe Company Announces First Quarter 2025 Financial Results • Net sales of $116.1 million increased 2.6% year-over-year • Net income of $0.39 per diluted share • Backlog1 of $203 million for the Engineered Steel Pressure Pipe segment (“SPP”); backlog including confirmed orders2 of $289 million • Order book3 of $64 million for the Precast Infrastructure and Engineered Systems

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 OR 15(d) of The Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): April 30, 2025 NORTHWEST PIPE COM

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 OR 15(d) of The Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): April 30, 2025 NORTHWEST PIPE COMPANY (Exact name of registrant as specified in its charter) Oregon 0-27140 93-0557988 (State or other jurisdiction of incorporation) (Commission File

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 14A INFORMATION Proxy Statement Pursuant to Section 14(a) of the Securities Exchange Act of 1934 (Amendment No. )

Table of Contents UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 14A INFORMATION Proxy Statement Pursuant to Section 14(a) of the Securities Exchange Act of 1934 (Amendment No. ) Filed by the Registrant ☒ Filed by a party other than the Registrant ☐ Check the appropriate box: ☐ Preliminary Proxy Statement ☐ Confidential, for Use of the Commission Only (as permitte

Form of Performance Share Unit Agreement

Exhibit 10.1 NORTHWEST PIPE COMPANY PERFORMANCE SHARE UNIT AGREEMENT This PERFORMANCE SHARE UNIT AGREEMENT (“Agreement”) is made and entered into as of March 27, 2025 (“Effective Date”) by and between Northwest Pipe Company (the “Company”), and XXX (the “Employee”) (collectively, the “Parties”). RECITALS The Company has determined that it would like to provide certain financial incentives to the E

Departure of Directors or Certain Officers; Election of Directors; Appointment of Certain Officers; Compensatory Arrangements of Certain Officers, Financial Statements and Exhibits, Other Events

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 OR 15(d) of The Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): March 27, 2025 NORTHWEST PIPE COMPANY (Exact name of registrant as specified in its charter) Oregon 0-27140 93-0557988 (State or other jurisdiction of incorporation) (Commission File

Form of Restricted Stock Unit Agreement

Exhibit 10.2 NORTHWEST PIPE COMPANY RESTRICTED STOCK UNIT AGREEMENT This RESTRICTED STOCK UNIT AGREEMENT (“Agreement”) is made and entered into as of March 27, 2025 (“Effective Date”) by and between Northwest Pipe Company (the “Company”), and XXX (the “Employee”) (collectively, the “Parties”). RECITALS The Company has determined that it would like to provide certain financial incentives to the Emp

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-K

Table of Contents UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-K (Mark One) ☒ ANNUAL REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the fiscal year ended: December 31, 2024 or ☐ TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period from to Commission file number: 0-271

Insider Trading Policy, filed herewith

Exhibit 19.1 Insider Trading Policy Revised 09/18/2024 Introduction 2 Scope 2 Prohibition on Trading While Aware of Material Nonpublic Information 2 Other Prohibitions on Trading Activities 3 Prohibition on Tipping Others 3 Blackout Periods and Covered Persons 3 Securities Transactions 3 Trading Compliance Officer 4 Rule 10b5-1 Safe Harbor 4 Individual Responsibility 5 Further Information 5 Acknow

Subsidiaries of the Registrant, filed herewith

EXHIBIT 21.1 NORTHWEST PIPE COMPANY SUBSIDIARIES OF THE REGISTRANT As of December 31, 2024 Permalok Corporation, Missouri Thompson Tank Holdings, Inc., Oregon NWPC, LLC, Delaware WTG Holding U.S., Inc., California Bolenco Corporation, California NWPC de SLRC, S de RL de CV, Mexico NWPC de Mexico, S de RL de CV, Mexico Rio Co., S de RL de CV, Mexico Corporacion Californiana de Tuberias APS, S de RL

Northwest Pipe Company Announces Fourth Quarter and Full Year 2024 Financial Results

Exhibit 99.1 Northwest Pipe Company Announces Fourth Quarter and Full Year 2024 Financial Results • Fourth quarter net sales of $119.6 million increased 8.6% year-over-year • Annual net sales of $492.5 million, a Company record under its current operating segments, increased 10.8% year-over-year • Record annual net sales for the Engineered Steel Pressure Pipe segment (“SPP”) and Precast Infrastruc

Financial Statements and Exhibits, Results of Operations and Financial Condition

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 OR 15(d) of The Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): February 26, 2025 NORTHWEST PIPE COMPANY (Exact name of registrant as specified in its charter) Oregon 0-27140 93-0557988 (State or other jurisdiction of incorporation) (Commission Fi

Departure of Directors or Certain Officers; Election of Directors; Appointment of Certain Officers; Compensatory Arrangements of Certain Officers, Financial Statements and Exhibits

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 OR 15(d) of The Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): December 10, 2024 -12-31 NORTHWEST PIPE COMPANY (Exact name of registrant as specified in its charter) Oregon 0-27140 93-0557988 (State or other jurisdiction of incorporation) (Commis

NWPX / Northwest Pipe Company / Global X Management CO LLC - SC 13G Passive Investment

SC 13G 1 ef20038667sc13g.htm SC 13G UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 13G INFORMATION STATEMENT TO BE INCLUDED IN STATEMENTS FILED PURSUANT TO RULES 13d-1 (b) (c) AND (d) AND AMENDMENTS THERETO FILED PURSUANT TO RULE 13d-2 (b) NORTHWEST PIPE COMPANY (Name of Issuer) Common Stock, par value $0.01 per share (Title of Class of Securities) 667746101 (CUSI

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-Q

Table of Contents UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-Q ☒ QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the quarterly period ended: September 30, 2024 or ☐ TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period from to Commission File Number: 0-27140

Term loan agreement dated October 28, 2024 by and between Wells Fargo Equipment Finance, Inc. and Geneva Pipe and Precast Company

Exhibit 10.1 Promissory Note Wells Fargo Equipment Finance, Inc. | 600 South 4th Street | MAC N9300-100 | Minneapolis, MN 55415 Notice: Lender reserves the right to withdraw the terms of this Promissory Note and issue a modified Promissory Note without notice to Debtor if Lender is not in receipt of a fully executed original or facsimile of this document within five (5) business days of the date o

Northwest Pipe Company Announces Third Quarter 2024 Financial Results

Exhibit 99.1 Northwest Pipe Company Announces Third Quarter 2024 Financial Results • Net sales of $130.2 million increased 9.7% year-over-year • Record net sales of $44.3 million for the Precast Infrastructure and Engineered Systems segment (“Precast”) • Record gross profit of $27.0 million increased 40.0% year-over-year; gross profit margin of 20.8% • Net income of $1.02 per diluted share • Gener

Financial Statements and Exhibits, Results of Operations and Financial Condition

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 OR 15(d) of The Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): October 30, 2024 NORTHWEST PIPE COMPANY (Exact name of registrant as specified in its charter) Oregon 0-27140 93-0557988 (State or other jurisdiction of incorporation) (Commission Fil

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-Q

Table of Contents UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-Q ☒ QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the quarterly period ended: June 30, 2024 or ☐ TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period from to Commission File Number: 0-27140 NORT

Northwest Pipe Company Announces Second Quarter 2024 Financial Results

Exhibit 99.1 Northwest Pipe Company Announces Second Quarter 2024 Financial Results • Net sales of $129.5 million increased 11.3% year-over-year • Record net sales of $89.5 million for the Engineered Steel Pressure Pipe segment (“SPP”) • Record gross profit of $25.8 million increased 14.8% year-over-year • Net income of $0.86 per diluted share • Generated strong net cash provided by operating acti

Financial Statements and Exhibits, Results of Operations and Financial Condition

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 OR 15(d) of The Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): July 31, 2024 NORTHWEST PIPE COMPANY (Exact name of registrant as specified in its charter) Oregon 0-27140 93-0557988 (State or other jurisdiction of incorporation) (Commission File N

Financial Statements and Exhibits, Submission of Matters to a Vote of Security Holders

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 OR 15(d) of The Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): June 13, 2024 NORTHWEST PIPE COMPANY (Exact name of registrant as specified in its charter) Oregon 0-27140 93-0557988 (State or other jurisdiction of incorporation) (Commission File N

Regulation FD Disclosure, Financial Statements and Exhibits

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 OR 15(d) of The Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): June 13, 2024 NORTHWEST PIPE COMPANY (Exact name of registrant as specified in its charter) Oregon 0-27140 93-0557988 (State or other jurisdiction of incorporation) (Commission File N

99.1 2024 Annual Shareholder Meeting Presentation dated June 13, 2024

Exhibit 99.1

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM SD SPECIALIZED DISCLOSURE REPORT NORTHWEST PIPE COMPANY (Exact name of registrant as specified in its charter)

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM SD SPECIALIZED DISCLOSURE REPORT NORTHWEST PIPE COMPANY (Exact name of registrant as specified in its charter) OREGON 0-27140 (State or other jurisdiction of incorporation) (Commission file number) 201 NE Park Plaza Drive, Suite 100 Vancouver, WA 98684 (Address of principal executive offices and Zip code) Aaron Wilkins Se

May 16, 2024

May 16, 2024 Via Edgar Filing Division of Corporation Finance U.S. Securities and Exchange Commission 100 F St, NE Washington, D.C. 20549 Attn: Stephany Yang and Melissa Gilmore RE: Northwest Pipe Company Form 10‑K for the Fiscal Year Ended December 31, 2023 Filed March 5, 2024 File No. 000‑27140 Dear Ms. Yang and Ms. Gilmore: Thank you for your comment regarding the above referenced filing. We ap

Change in Control Agreement dated December 9, 2021 between Northwest Pipe Company and Michael Wray

Exhibit 10.4 December 9, 2021 Michael Wray Northwest Pipe Company, an Oregon corporation (the "Company"), considers the establishment and maintenance of a sound and vital management to be essential to protecting and enhancing the best interests of the Company and its shareholders. In this connection, the Company recognizes that, as is the case with many publicly held corporations, the possibility

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-Q

Table of Contents UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-Q ☒ QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the quarterly period ended: March 31, 2024 or ☐ TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period from to Commission File Number: 0-27140 NOR

Change in Control Agreement dated April 1, 2020 between Northwest Pipe Company and Eric Stokes

Exhibit 10.3 April 1, 2020 Eric Stokes Northwest Pipe Company, an Oregon corporation (the “Company”), considers the establishment and maintenance of a sound and vital management to be essential to protecting and enhancing the best interests of the Company and its shareholders. In this connection, the Company recognizes that, as is the case with many publicly held corporations, the possibility of a

Northwest Pipe Company Announces First Quarter 2024 Financial Results

Exhibit 99.1 Northwest Pipe Company Announces First Quarter 2024 Financial Results • Net sales of $113.2 million increased 14.2% year-over-year, a record for first quarter revenues • Gross profit of $20.1 million increased 21.5% year-over-year, the highest first quarter gross profit in 11 years • Net income of $0.52 per diluted share • Backlog1 of $255 million; backlog including confirmed orders2

Financial Statements and Exhibits, Results of Operations and Financial Condition

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 OR 15(d) of The Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): May 1, 2024 NORTHWEST PIPE COMPANY (Exact name of registrant as specified in its charter) Oregon 0-27140 93-0557988 (State or other jurisdiction of incorporation) (Commission File Num

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 14A INFORMATION Proxy Statement Pursuant to Section 14(a) of the Securities Exchange Act of 1934 (Amendment No. )

Table of Contents UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 14A INFORMATION Proxy Statement Pursuant to Section 14(a) of the Securities Exchange Act of 1934 (Amendment No. ) Filed by the Registrant ☒ Filed by a party other than the Registrant ☐ Check the appropriate box: ☐ Preliminary Proxy Statement ☐ Confidential, for Use of the Commission Only (as permitte

Form of Performance Share Unit Agreement

Exhibit 10.1 NORTHWEST PIPE COMPANY PERFORMANCE SHARE UNIT AGREEMENT This PERFORMANCE SHARE UNIT AGREEMENT (“Agreement”) is made and entered into as of March 28, 2024 (“Effective Date”) by and between Northwest Pipe Company (the “Company”), and XXX (the “Employee”) (collectively, the “Parties”). RECITALS The Company has determined that it would like to provide certain financial incentives to the E

Form of Restricted Stock Unit Agreement

EX-10.2 3 ex612333.htm EXHIBIT 10.2 Exhibit 10.2 NORTHWEST PIPE COMPANY RESTRICTED STOCK UNIT AGREEMENT This RESTRICTED STOCK UNIT AGREEMENT (“Agreement”) is made and entered into as of March 28, 2024 (“Effective Date”) by and between Northwest Pipe Company (the “Company”), and XXX (the “Employee”) (collectively, the “Parties”). RECITALS The Company has determined that it would like to provide cer

Departure of Directors or Certain Officers; Election of Directors; Appointment of Certain Officers; Compensatory Arrangements of Certain Officers, Financial Statements and Exhibits, Other Events

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 OR 15(d) of The Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): March 28, 2024 NORTHWEST PIPE COMPANY (Exact name of registrant as specified in its charter) Oregon 0-27140 93-0557988 (State or other jurisdiction of incorporation) (Commission File

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-K

Table of Contents UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-K (Mark One) ☒ ANNUAL REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the fiscal year ended: December 31, 2023 or ☐ TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period from to Commission file number: 0-271

Subsidiaries of the Registrant, filed herewith

EXHIBIT 21.1 NORTHWEST PIPE COMPANY SUBSIDIARIES OF THE REGISTRANT As of December 31, 2023 Permalok Corporation, Missouri Thompson Tank Holdings, Inc., Oregon NWPC, LLC, Delaware WTG Holding U.S., Inc., California Bolenco Corporation, California NWPC de SLRC, S de RL de CV, Mexico NWPC de Mexico, S de RL de CV, Mexico Rio Co., S de RL de CV, Mexico Corporacion Californiana de Tuberias APS, S de RL

Incentive Compensation Recovery Policy

EXHIBIT 97 POLICY RELATING TO RECOVERY OF ERRONEOUSLY AWARDED COMPENSATION Incentive Compensation Recovery Policy Adopted September 14, 2023 Introduction The Board of Directors (“Board”) of Northwest Pipe Company (“Company”) has determined that it is in the best interests of the Company and its shareholders to maintain and promote a culture emphasizing integrity and accountability by, among other things, reinforcing the pay-for-performance compensation philosophy applicable to the officers and employees of the Company.

Financial Statements and Exhibits, Results of Operations and Financial Condition

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 OR 15(d) of The Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): March 4, 2024 NORTHWEST PIPE COMPANY (Exact name of registrant as specified in its charter) Oregon 0-27140 93-0557988 (State or other jurisdiction of incorporation) (Commission File N

Northwest Pipe Company Announces Fourth Quarter and Full Year 2023 Financial Results

Exhibit 99.1 Northwest Pipe Company Announces Fourth Quarter and Full Year 2023 Financial Results • Fourth quarter 2023 net sales of $110.2 million increased 3.1% year-over-year • Annual net sales of $444.4 million decreased 2.9% year-over-year • Annual gross profit of $77.6 million decreased 9.6% year-over-year from 2022 record • Annual net income of $2.09 per diluted share • Strong annual cash g

NWPX / Northwest Pipe Company / DIMENSIONAL FUND ADVISORS LP - SEC SCHEDULE 13G Passive Investment

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 13G Under the Securities Exchange Act of 1934 (Amendment No. 23 )* Northwest Pipe Co (Name of Issuer) Common Stock (Title of Class of Securities) 667746101 (CUSIP Number) December 29, 2023 (Date of Event Which Requires Filing of this Statement) Check the appropriate box to designate the rule pursuant to which this Sch

Current Report

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 OR 15(d) of The Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): December 13, 2023 -12-31 NORTHWEST PIPE COMPANY (Exact name of registrant as specified in its charter) Oregon 0-27140 93-0557988 (State or other jurisdiction of incorporation) (Commis

Amended and Restated Bylaws, incorporated by reference to the Company’s Current Report on Form 8‑K as filed with the Securities and Exchange Commission on December 19, 2023

Exhibit 3.1 AMENDED AND RESTATED BYLAWS OF NORTHWEST PIPE COMPANY (Adopted December 14, 2023) ARTICLE I OFFICES 1.1. Principal Office. The principal office of the corporation shall be located at the place designated by the Board of Directors from time to time. The corporation may have such other offices as the Board of Directors may designate or as the business of the corporation may from time to

Northwest Pipe Company 201 NE Park Plaza Drive, Suite 100 Vancouver, Washington 98684

Northwest Pipe Company 201 NE Park Plaza Drive, Suite 100 Vancouver, Washington 98684 November 29, 2023 VIA EDGAR United States Securities and Exchange Commission Division of Corporation Finance 100 F Street, N.

As filed with the Securities and Exchange Commission on November 21, 2023

Table of Contents As filed with the Securities and Exchange Commission on November 21, 2023 Registration No.

Filing Fee Table

Exhibit 107 Calculation of Filing Fee Tables Form S-3 (Form Type) Northwest Pipe Company (Exact Name of Registrant as Specified in its Charter) Table 1: Newly Registered Securities Security Type Security Class Title Fee Calculation or Carry Forward Rule Amount Registered Proposed Maximum Offering Price Per Unit Maximum Aggregate Offering Price Fee Rate Amount of Registration Fee Carry Forward Form Type Carry Forward File Number Carry Forward Initial effective date Filing Fee Previously Paid In Connection with Unsold Securities to be Carried Forward Newly Registered Securities Fees to Be Paid Equity Common stock, $0.

Form of Indenture

Exhibit 4.4 NORTHWEST PIPE COMPANY INDENTURE Dated as of , 20 [], Trustee TABLE OF CONTENTS Page ARTICLE I. DEFINITIONS AND INCORPORATION BY REFERENCE 1 Section 1.1. Definitions. 1 Section 1.2. Other Definitions. 3 Section 1.3. Incorporation by Reference of Trust Indenture Act. 3 Section 1.4. Rules of Construction. 4 ARTICLE II. THE SECURITIES 4 Section 2.1. Issuable in Series. 4 Section 2.2. Esta

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-Q

Table of Contents UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-Q ☒ QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the quarterly period ended: September 30, 2023 or ☐ TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period from to Commission File Number: 0-27140

Financial Statements and Exhibits, Results of Operations and Financial Condition

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 OR 15(d) of The Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): November 2, 2023 NORTHWEST PIPE COMPANY (Exact name of registrant as specified in its charter) Oregon 0-27140 93-0557988 (State or other jurisdiction of incorporation) (Commission Fil

Northwest Pipe Company Announces Third Quarter 2023 Financial Results and Share Repurchase Authorization

Exhibit 99.1 Northwest Pipe Company Announces Third Quarter 2023 Financial Results and Share Repurchase Authorization • Net sales of $118.7 million decreased 3.5% year-over-year • Gross profit of $19.3 million decreased 23.2% year-over-year • Net income of $0.58 per diluted share • Backlog1 of $253 million; backlog including confirmed orders2 of $335 million for the Engineered Steel Pressure Pipe

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-Q

Table of Contents UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-Q ☒ QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the quarterly period ended: June 30, 2023 or ☐ TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period from to Commission File Number: 0-27140 NORT

Northwest Pipe Company Announces Second Quarter 2023 Financial Results

Exhibit 99.1 Northwest Pipe Company Announces Second Quarter 2023 Financial Results • Net sales of $116.4 million decreased 1.8% year-over-year • Gross profit of $22.5 million decreased 6.6% year-over-year • Net income of $0.74 per diluted share • Backlog1 of $292 million; backlog including confirmed orders2 of $343 million for the Engineered Steel Pressure Pipe segment (“SPP”) • Order book3 of $5

Financial Statements and Exhibits, Results of Operations and Financial Condition

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 OR 15(d) of The Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): August 2, 2023 NORTHWEST PIPE COMPANY (Exact name of registrant as specified in its charter) Oregon 0-27140 93-0557988 (State or other jurisdiction of incorporation) (Commission File

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 OR 15(d) of The Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): June 29, 2023 NORTHWEST PIPE COMP

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 OR 15(d) of The Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): June 29, 2023 NORTHWEST PIPE COMPANY (Exact name of registrant as specified in its charter) Oregon 0-27140 93-0557988 (State or other jurisdiction of incorporation) (Commission File N

Third Amendment to Credit Agreement dated as of June 29, 2023, by and among Northwest Pipe Company, NWPC, LLC, Geneva Pipe and Precast Company, Park Environmental Equipment, LLC, certain other subsidiaries of Northwest Pipe Company, and Wells Fargo Bank National Association, incorporated by reference to the Company’s Current Report on Form 8‑K, as filed with the Securities and Exchange Commission on July 3, 2023**

Exhibit 10.1 THIRD AMENDMENT TO CREDIT AGREEMENT This THIRD AMENDMENT TO CREDIT AGREEMENT, dated as of June 29, 2023 (this “Amendment”), is by and among NORTHWEST PIPE COMPANY, an Oregon corporation (“Administrative Borrower”), NWPC, LLC, a Delaware limited liability company (“NWPC”), GENEVA PIPE AND PRECAST COMPANY, a Utah corporation (“Geneva”), PARK ENVIRONMENTAL EQUIPMENT, LLC, a Texas limited

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 OR 15(d) of The Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): June 22, 2023 NORTHWEST PIPE COMP

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 OR 15(d) of The Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): June 22, 2023 NORTHWEST PIPE COMPANY (Exact name of registrant as specified in its charter) Oregon 0-27140 93-0557988 (State or other jurisdiction of incorporation) (Commission File N

99.1 2023 Annual Shareholder Meeting Presentation dated June 22, 2023

Exhibit 99.1

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 OR 15(d) of The Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): June 22, 2023 NORTHWEST PIPE COMP

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 OR 15(d) of The Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): June 22, 2023 NORTHWEST PIPE COMPANY (Exact name of registrant as specified in its charter) Oregon 0-27140 93-0557988 (State or other jurisdiction of incorporation) (Commission File N

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM SD SPECIALIZED DISCLOSURE REPORT NORTHWEST PIPE COMPANY (Exact name of registrant as specified in its charter)

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM SD SPECIALIZED DISCLOSURE REPORT NORTHWEST PIPE COMPANY (Exact name of registrant as specified in its charter) OREGON 0-27140 (State or other jurisdiction of incorporation) (Commission file number) 201 NE Park Plaza Drive, Suite 100 Vancouver, WA 98684 (Address of principal executive offices and Zip code) Aaron Wilkins Se

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-Q

Table of Contents UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-Q ☒ QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the quarterly period ended: March 31, 2023 or ☐ TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period from to Commission File Number: 0-27140 NOR

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 OR 15(d) of The Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): May 3, 2023 NORTHWEST PIPE COMPAN

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 OR 15(d) of The Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): May 3, 2023 NORTHWEST PIPE COMPANY (Exact name of registrant as specified in its charter) Oregon 0-27140 93-0557988 (State or other jurisdiction of incorporation) (Commission File Num

Northwest Pipe Company Announces First Quarter 2023 Financial Results

Exhibit 99.1 Northwest Pipe Company Announces First Quarter 2023 Financial Results • Net sales of $99.1 million decreased 9.4% year-over-year; Precast Infrastructure and Engineered Systems segment (“Precast”) net sales increased 2.7% year-over-year • Gross profit of $16.6 million increased 12.1% year-over-year • Net income of $0.23 per diluted share • Backlog1 of $297 million; backlog including co

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 14A INFORMATION Proxy Statement Pursuant to Section 14(a) of the Securities Exchange Act of 1934 (Amendment No. )

Table of Contents UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 14A INFORMATION Proxy Statement Pursuant to Section 14(a) of the Securities Exchange Act of 1934 (Amendment No. ) Filed by the Registrant ☒ Filed by a party other than the Registrant ☐ Check the appropriate box: ☐ Preliminary Proxy Statement ☐ Confidential, for Use of the Commission Only (as permitte

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 OR 15(d) of The Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): April 21, 2023 NORTHWEST PIPE COM

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 OR 15(d) of The Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): April 21, 2023 NORTHWEST PIPE COMPANY (Exact name of registrant as specified in its charter) Oregon 0-27140 93-0557988 (State or other jurisdiction of incorporation) (Commission File

Departure of Directors or Certain Officers; Election of Directors; Appointment of Certain Officers; Compensatory Arrangements of Certain Officers, Financial Statements and Exhibits

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K/A (Amendment No. 1) CURRENT REPORT Pursuant to Section 13 OR 15(d) of The Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): February 22, 2023 NORTHWEST PIPE COMPANY (Exact name of registrant as specified in its charter) Oregon 0-27140 93-0557988 (State or other jurisdiction of incorpora

Form of Performance Share Unit Agreement, incorporated by reference to the Company’s Current Report on Form 8‑K, as filed with the Securities and Exchange Commission on April 13, 2023*

Exhibit 10.1 NORTHWEST PIPE COMPANY PERFORMANCE SHARE UNIT AGREEMENT This PERFORMANCE SHARE UNIT AGREEMENT (“Agreement”) is made and entered into as of April 8, 2023 (“Effective Date”) by and between Northwest Pipe Company (the “Company”), and XXX (the “Employee”) (collectively, the “Parties”). RECITALS The Company has determined that it would like to provide certain financial incentives to the Em

Departure of Directors or Certain Officers; Election of Directors; Appointment of Certain Officers; Compensatory Arrangements of Certain Officers, Financial Statements and Exhibits

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 OR 15(d) of The Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): April 8, 2023 NORTHWEST PIPE COMPANY (Exact name of registrant as specified in its charter) Oregon 0-27140 93-0557988 (State or other jurisdiction of incorporation) (Commission File N

Form of Restricted Stock Unit Agreement, incorporated by reference to the Company’s Current Report on Form 8‑K, as filed with the Securities and Exchange Commission on April 13, 2023*

Exhibit 10.2 NORTHWEST PIPE COMPANY RESTRICTED STOCK UNIT AGREEMENT This RESTRICTED STOCK UNIT AGREEMENT (“Agreement”) is made and entered into as of April 8, 2023 (“Effective Date”) by and between Northwest Pipe Company (the “Company”), and XXX (the “Employee”) (collectively, the “Parties”). RECITALS The Company has determined that it would like to provide certain financial incentives to the Empl

Subsidiaries of the Registrant, filed herewith

EXHIBIT 21.1 NORTHWEST PIPE COMPANY SUBSIDIARIES OF THE REGISTRANT As of December 31, 2022 Permalok Corporation, Missouri Thompson Tank Holdings, Inc., Oregon NWPC, LLC, Delaware WTG Holding U.S., Inc., California Bolenco Corporation, California NWPC de SLRC, S de RL de CV, Mexico NWPC de Mexico, S de RL de CV, Mexico Rio Co., S de RL de CV, Mexico Corporacion Californiana de Tuberias APS, S de RL

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-K

Table of Contents UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-K (Mark One) ☒ ANNUAL REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the fiscal year ended: December 31, 2022 or ☐ TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period from to Commission file number: 0-271

Northwest Pipe Company Announces Fourth Quarter and Full Year 2022 Financial Results

Exhibit 99.1 Northwest Pipe Company Announces Fourth Quarter and Full Year 2022 Financial Results • Annual net sales of $457.7 million increased 37.3% year-over-year • Record annual gross profit of $85.9 million increased 94.0% year-over-year • Record annual net income of $3.11 per diluted share; adjusted net income of $3.35 per diluted share • Backlog1 of $274 million; backlog including confirmed

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 OR 15(d) of The Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): March 15, 2023 NORTHWEST PIPE COM

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 OR 15(d) of The Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): March 15, 2023 NORTHWEST PIPE COMPANY (Exact name of registrant as specified in its charter) Oregon 0-27140 93-0557988 (State or other jurisdiction of incorporation) (Commission File

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 OR 15(d) of The Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): February 22, 2023 NORTHWEST PIPE

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 OR 15(d) of The Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): February 22, 2023 NORTHWEST PIPE COMPANY (Exact name of registrant as specified in its charter) Oregon 0-27140 93-0557988 (State or other jurisdiction of incorporation) (Commission Fi

Northwest Pipe Company Elects Irma Lockridge to its Board of Directors New Director brings expertise in human capital and executive leadership.

Exhibit 99.1 MEDIA RELEASE FOR IMMEDIATE RELEASE – February 24, 2023 Contact: Aaron Wilkins Chief Financial Officer Northwest Pipe Company 360-397-6294 • [email protected] Northwest Pipe Company Elects Irma Lockridge to its Board of Directors New Director brings expertise in human capital and executive leadership. VANCOUVER, Washington: Northwest Pipe Company (Nasdaq: NWPX), a leading manufactur

NWPX / Northwest Pipe Company / DIMENSIONAL FUND ADVISORS LP - SEC SCHEDULE 13G Passive Investment

SC 13G/A 1 SEC13GFiling.htm SEC SCHEDULE 13G UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 13G Under the Securities Exchange Act of 1934 (Amendment No. 22 )* Northwest Pipe Co (Name of Issuer) Common Stock (Title of Class of Securities) 667746101 (CUSIP Number) December 30, 2022 (Date of Event Which Requires Filing of this Statement) Check the appropriate box to

Current Report

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 OR 15(d) of The Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): December 6, 2022 NORTHWEST PIPE COMPANY (Exact name of registrant as specified in its charter) Oregon 0-27140 93-0557988 (State or other jurisdiction of incorporation) (Commission Fil

Form of Indemnification Agreement, incorporated by reference to the Company’s Current Report on Form 8‑K as filed with the Securities and Exchange Commission on December 12, 2022

Exhibit 10.1 NORTHWEST PIPE COMPANY FORM OF INDEMNIFICATION AGREEMENT This Indemnification Agreement (this ?Agreement?) is dated as of , and is between Northwest Pipe Company, an Oregon corporation (the ?Company?), and (?Indemnitee?). RECITALS A. Indemnitee?s service to the Company substantially benefits the Company. B. Individuals are reluctant to serve as directors or officers of corporations or

3.1 Amended and Restated Bylaws

Exhibit 3.1 AMENDED AND RESTATED BYLAWS OF NORTHWEST PIPE COMPANY (Adopted December 6, 2022) ARTICLE I OFFICES 1.1 Principal Office. The principal office of the corporation shall be located at the place designated by the Board of Directors from time to time. The corporation may have such other offices as the Board of Directors may designate or as the business of the corporation may from time to ti

Interim Funding Agreement dated August 2, 2022 by and between Wells Fargo Equipment Finance, Inc. and Geneva Pipe and Precast Company, incorporated by reference to the Company’s Form 10‑Q for the quarter ended September 30, 2022, as filed with the Securities and Exchange Commission on November 9, 2022

Exhibit 99.1 Interim Funding Agreement Wells Fargo Equipment Finance, Inc. I 600 South 4th Street I MAC N9300-100 I Minneapolis, MN 55415 This Agreement dated as of August 2, 2022 by and between Wells Fargo Equipment Finance, Inc. ("Creditor") and the undersigned lessee or purchaser or borrower from Creditor, as the case may be (the "Customer"). WHEREAS Creditor has agreed to finance certain equip

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-Q

Table of Contents UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-Q ☒ QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the quarterly period ended: September 30, 2022 or ☐ TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period from to Commission File Number: 0-27140

Northwest Pipe Company Announces Third Quarter 2022 Financial Results

Exhibit 99.1 Northwest Pipe Company Announces Third Quarter 2022 Financial Results ? Net sales of $123.0 million increased 45.3% year-over-year ? Gross profit of $25.1 million increased 103.2% year-over-year ? Net income of $0.99 per diluted share; adjusted net income of $1.05 per diluted share ? Backlog1 of $295 million; backlog including confirmed orders2 of $347 million for the Engineered Steel

Financial Statements and Exhibits, Results of Operations and Financial Condition

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 OR 15(d) of The Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): November 8, 2022 NORTHWEST PIPE COMPANY (Exact name of registrant as specified in its charter) Oregon 0-27140 93-0557988 (State or other jurisdiction of incorporation) (Commission Fil

Current Report

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 OR 15(d) of The Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): September 2, 2022 NORTHWEST PIPE COMPANY (Exact name of registrant as specified in its charter) Oregon 0-27140 93-0557988 (State or other jurisdiction of incorporation) (Commission Fi

Up to $50,000,000 Common Stock

Table of Contents ?Filed Pursuant to Rule 424(b)(5) ?Registration No. 333?249637 PROSPECTUS SUPPLEMENT (To Prospectus dated November 3, 2020) Up to $50,000,000 Common Stock We have entered into an Open Market Sale Agreement SM (the ?Sales Agreement?) with Jefferies LLC (?Jefferies?) relating to shares of our common stock, par value $0.01 per share, offered by this prospectus supplement and the acc

Open Market Sale AgreementSM, dated September 2, 2022 between Northwest Pipe Company and Jefferies LLC, incorporated by reference to the Company’s Current Report on Form 8‑K, as filed with the Securities and Exchange Commission on September 2, 2022

Exhibit 1.1 OPEN MARKET SALE AGREEMENT SM September 2, 2022 JEFFERIES LLC 520 Madison Avenue New York, New York 10022 Ladies and Gentlemen: Northwest Pipe Company, an Oregon corporation (the ?Company?), proposes, subject to the terms and conditions stated herein, to issue and sell from time to time through Jefferies LLC, as sales agent and/or principal (the ?Agent?), shares of the Company?s common

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-Q

Table of Contents UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-Q ? QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the quarterly period ended: June 30, 2022 or ? TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period from to Commission File Number: 0-27140 NORT

Financial Statements and Exhibits, Results of Operations and Financial Condition

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 OR 15(d) of The Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): August 8, 2022 NORTHWEST PIPE COMPANY (Exact name of registrant as specified in its charter) Oregon 0-27140 93-0557988 (State or other jurisdiction of incorporation) (Commission File

Northwest Pipe Company Announces Second Quarter 2022 Financial Results

Exhibit 99.1 Northwest Pipe Company Announces Second Quarter 2022 Financial Results ? Net sales of $118.5 million increased 60.6% year-over-year ? Gross profit of $24.1 million increased 152.5% year-over-year ? Net income of $0.97 per diluted share; adjusted net income of $1.04 per diluted share ? Record quarterly profits and revenues for both of the recently acquired Precast Infrastructure and En

Financial Statements and Exhibits, Other Events

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 OR 15(d) of The Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): June 23, 2022 NORTHWEST PIPE COMPANY (Exact name of registrant as specified in its charter) Oregon 0-27140 93-0557988 (State or other jurisdiction of incorporation) (Commission File N

Departure of Directors or Certain Officers; Election of Directors; Appointment of Certain Officers; Compensatory Arrangements of Certain Officers, Financial Statements and Exhibits

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 OR 15(d) of The Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): June 16, 2022 NORTHWEST PIPE COMPANY (Exact name of registrant as specified in its charter) Oregon 0-27140 93-0557988 (State or other jurisdiction of incorporation) (Commission File N

Form of Restricted Stock Unit Agreement, incorporated by reference to the Company’s Current Report on Form 8‑K, as filed with the Securities and Exchange Commission on June 23, 2022 *

Exhibit 10.2 NORTHWEST PIPE COMPANY RESTRICTED STOCK UNIT AGREEMENT This RESTRICTED STOCK UNIT AGREEMENT (?Agreement?) is made and entered into as of June 16, 2022 (?Effective Date?) by and between Northwest Pipe Company (the ?Company?), and XXX (the ?Employee?) (collectively, the ?Parties?). RECITALS The Company has determined that it would like to provide certain financial incentives to the Empl

Form of Performance Share Unit Agreement, incorporated by reference to the Company’s Current Report on Form 8‑K, as filed with the Securities and Exchange Commission on June 23, 2022 *

Exhibit 10.1 NORTHWEST PIPE COMPANY PERFORMANCE SHARE UNIT AGREEMENT This PERFORMANCE SHARE UNIT AGREEMENT (?Agreement?) is made and entered into as of June 16, 2022 (?Effective Date?) by and between Northwest Pipe Company (the ?Company?), and XXX (the ?Employee?) (collectively, the ?Parties?). RECITALS The Company has determined that it would like to provide certain financial incentives to the Em

Filing Fee Table

Exhibit 107 Calculation of Filing Fee Tables FORM S-8 (Form Type) Northwest Pipe Company (Exact Name of Registrant as Specified in its Charter) Table 1: Newly Registered Securities Security Type Security Class Title Fee Calculation Rule Amount Registered (1) Proposed Maximum Offering Price Per Unit Per Share Maximum Aggregate Offering Price Fee Rate Amount of Registration Fee Equity Common Stock, par value $.

Current Report

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 OR 15(d) of The Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): June 16, 2022 NORTHWEST PIPE COMPANY (Exact name of registrant as specified in its charter) oregon 0-27140 93-0557988 (State or other jurisdiction of incorporation) (Commission File N

99.1 2022 Annual Shareholder Meeting Presentation dated June 16, 2022

Exhibit 99.1

As filed with the Securities and Exchange Commission on June 16, 2022

As filed with the Securities and Exchange Commission on June 16, 2022 Registration No.

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM SD SPECIALIZED DISCLOSURE REPORT NORTHWEST PIPE COMPANY (Exact name of registrant as specified in its charter)

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM SD SPECIALIZED DISCLOSURE REPORT NORTHWEST PIPE COMPANY (Exact name of registrant as specified in its charter) OREGON 0-27140 (State or other jurisdiction of incorporation) (Commission file number) 201 NE Park Plaza Drive, Suite 100 Vancouver, WA 98684 (Address of principal executive offices and Zip code) Aaron Wilkins Se

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-Q

Table of Contents UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-Q ? QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the quarterly period ended: March 31, 2022 or ? TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period from to Commission File Number: 0-27140 NOR

Second Amendment to Credit Agreement dated April 29, 2022 by and among Northwest Pipe Company, NWPC, LLC, Geneva Pipe and Precast Company, Park Environmental Equipment, LLC, certain other subsidiaries of Northwest Pipe Company, and Wells Fargo Bank, National Association, incorporated by reference to the Company’s Form 10‑Q for the quarter ended March 31, 2022, as filed with the Securities and Exchange Commission on May 6, 2022

Exhibit 10.2 Execution Copy SECOND AMENDMENT TO CREDIT AGREEMENT This SECOND AMENDMENT TO CREDIT AGREEMENT, dated as of April 29, 2022 (this ?Amendment?), is by and among NORTHWEST PIPE COMPANY, an Oregon corporation (?Administrative Borrower?), NWPC, LLC, a Delaware limited liability company (?NWPC?), GENEVA PIPE AND PRECAST COMPANY, a Utah corporation (?Geneva?), PARK ENVIRONMENTAL EQUIPMENT, LL

Northwest Pipe Company Announces First Quarter 2022 Financial Results

Exhibit 99.1 Northwest Pipe Company Announces First Quarter 2022 Financial Results ? Net sales of $109.3 million increased 51.2% year-over-year ? Gross profit of $14.8 million increased 68.5% year-over-year ? Backlog1 of $200 million; backlog including confirmed orders2 of $341 million for the Engineered Steel Pressure Pipe segment (?SPP?), a new quarterly record ? Record order book3 of $66 millio

Financial Statements and Exhibits, Results of Operations and Financial Condition

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 OR 15(d) of The Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): May 4, 2022 NORTHWEST PIPE COMPANY (Exact name of registrant as specified in its charter) Oregon 0-27140 93-0557988 (State or other jurisdiction of incorporation) (Commission File Num

2022 Stock Incentive Plan, incorporated by reference to the Company’s definitive proxy statement on Schedule 14A filed with the Securities and Exchange Commission on April 28, 2022

Table of Contents UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 14A INFORMATION Proxy Statement Pursuant to Section 14(a) of the Securities Exchange Act of 1934 (Amendment No. ) Filed by the Registrant ? Filed by a party other than the Registrant ? Check the appropriate box: ? Preliminary Proxy Statement ? Confidential, for Use of the Commission Only (as permitte

Departure of Directors or Certain Officers; Election of Directors; Appointment of Certain Officers; Compensatory Arrangements of Certain Officers, Financial Statements and Exhibits

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 OR 15(d) of The Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): April 7, 2022 NORTHWEST PIPE COMPANY (Exact name of registrant as specified in its charter) Oregon 0-27140 93-0557988 (State or other jurisdiction of incorporation) (Commission File N

Separation Agreement dated April 8, 2022 between Northwest Pipe Company and William Smith, incorporated by reference to the Company’s Current Report on Form 8‑K, as filed with the Securities and Exchange Commission on April 13, 2022

Exhibit 10.1 April 7, 2022 William M. Smith Re: Confidential Employment Separation Agreement Dear Bill: As we discussed, you have notified Northwest Pipe Co. (the ?Company?) that you wish to resign, and the Company has accepted your resignation from your full time role, effective April 15, 2022. Provided below in Part I (?Separation from Employment?) are details regarding your final pay and other

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-K

Table of Contents UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-K (Mark One) ? ANNUAL REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the fiscal year ended: December 31, 2021 or ? TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period from to Commission file number: 0-271

Second Restated Articles of Incorporation, incorporated by reference to the Company’s Annual Report on Form 10‑K for the year ended December 31, 2021, as filed with the Securities and Exchange Commission on March 16, 2022

Exhibit 3.1 SECOND RESTATED ARTICLES OF INCORPORATION OF NORTHWEST PIPE COMPANY Pursuant to ORS 60.451, these Second Restated Articles of Incorporation supersede the existing articles and all previous amendments (these ?Articles?). ARTICLE I The name of this Corporation shall be Northwest Pipe Company and its duration shall be perpetual. ARTICLE II A. The authorized capital stock of the Corporatio

Subsidiaries of the Registrant, filed herewith

EXHIBIT 21.1 NORTHWEST PIPE COMPANY SUBSIDIARIES OF THE REGISTRANT As of December 31, 2021 Permalok Corporation, Missouri Thompson Tank Holdings, Inc., Oregon NWPC, LLC, Delaware WTG Holding U.S., Inc., California Bolenco Corporation, California NWPC de SLRC, S de RL de CV, Mexico NWPC de Mexico, S de RL de CV, Mexico Rio Co., S de RL de CV, Mexico Corporacion Californiana de Tuberias APS, S de RL

Financial Statements and Exhibits, Results of Operations and Financial Condition

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 OR 15(d) of The Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): March 15, 2022 NORTHWEST PIPE COMPANY (Exact name of registrant as specified in its charter) Oregon 0-27140 93-0557988 (State or other jurisdiction of incorporation) (Commission File

Northwest Pipe Company Announces Fourth Quarter and Full Year 2021 Financial Results

Exhibit 99.1 Northwest Pipe Company Announces Fourth Quarter and Full Year 2021 Financial Results ? Annual net sales of $333.3 million increased 16.6% year-over-year ? Record full-year sales levels achieved at both recently acquired precast companies ? Backlog of $183 million; record backlog including confirmed orders of $290 million for the Engineered Steel Pressure Pipe segment ? Record order bo

Financial Statements and Exhibits

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 OR 15(d) of The Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): March 3, 2022 NORTHWEST PIPE COMPANY (Exact name of registrant as specified in its charter) Oregon 0-27140 93-0557988 (State or other jurisdiction of incorporation) (Commission File N

Departure of Directors or Certain Officers; Election of Directors; Appointment of Certain Officers; Compensatory Arrangements of Certain Officers, Financial Statements and Exhibits

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 OR 15(d) of The Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): February 9, 2022 NORTHWEST PIPE COMPANY (Exact name of registrant as specified in its charter) Oregon 0-27140 93-0557988 (State or other jurisdiction of incorporation) (Commission Fil

NWPX / Northwest Pipe Company / DIMENSIONAL FUND ADVISORS LP - SEC SCHEDULE 13G Passive Investment

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 13G Under the Securities Exchange Act of 1934 (Amendment No. 21 )* Northwest Pipe Co (Name of Issuer) Common Stock (Title of Class of Securities) 667746101 (CUSIP Number) December 31, 2021 (Date of Event Which Requires Filing of this Statement) Check the appropriate box to designate the rule pursuant to which this Sch

Financial Statements and Exhibits

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K/A (Amendment No. 1) CURRENT REPORT Pursuant to Section 13 OR 15(d) of The Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): October 5, 2021 NORTHWEST PIPE COMPANY (Exact name of registrant as specified in its charter) Oregon 0-27140 93-0557988 (State or other jurisdiction of incorporati

TABLE OF CONTENTS

Exhibit 99.1 Park Environmental Equipment, Ltd. Financial Statements December 31, 2020 TABLE OF CONTENTS Page No. Independent Auditor's Report 1 Balance Sheet 2 Statement of Income 3 Statement of Changes in Partners' Capital 4 Statement of Cash Flows 5 Notes to Financial Statements 6-10 INDEPENDENT AUDITOR'S REPORT To the Partners of Park Environmental Equipment, Ltd. Houston, TX We have audited t

UNAUDITED PRO FORMA CONDENSED COMBINED FINANCIAL INFORMATION

EX-99.3 5 ex314893.htm EXHIBIT 99.3 Exhibit 99.3 UNAUDITED PRO FORMA CONDENSED COMBINED FINANCIAL INFORMATION Northwest Pipe Company (the “Company”) acquired Park Environmental Equipment, LLC (“ParkUSA”) on October 5, 2021 for total consideration of approximately $87.5 million, subject to a post-closing adjustment based on changes in net working capital. The Company financed the acquisition primar

PARK ENVIRONMENTAL EQUIPMENT, LLC Interim Financial Statements As of September 30, 2021 and December 31, 2020 and for the Nine Months Ended September 30, 2021 and 2020 PARK ENVIRONMENTAL EQUIPMENT, LLC INTERIM FINANCIAL STATEMENTS TABLE OF CONTENTS

Exhibit 99.2 PARK ENVIRONMENTAL EQUIPMENT, LLC Interim Financial Statements (Unaudited) As of September 30, 2021 and December 31, 2020 and for the Nine Months Ended September 30, 2021 and 2020 PARK ENVIRONMENTAL EQUIPMENT, LLC INTERIM FINANCIAL STATEMENTS TABLE OF CONTENTS (Unaudited) Page Statements of Operations for the nine months ended September 30, 2021 and 2020 1 Balance Sheets as of Septemb

Departure of Directors or Certain Officers; Election of Directors; Appointment of Certain Officers; Compensatory Arrangements of Certain Officers, Financial Statements and Exhibits

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 OR 15(d) of The Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): December 9, 2021 NORTHWEST PIPE COMPANY (Exact name of registrant as specified in its charter) Oregon 0-27140 93-0557988 (State or other jurisdiction of incorporation) (Commission Fil

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-Q

Table of Contents UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-Q ? QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the quarterly period ended: September 30, 2021 or ? TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period from to Commission File Number: 0-27140

Northwest Pipe Company Announces Third Quarter 2021 Financial Results

Exhibit 99.1 Northwest Pipe Company Announces Third Quarter 2021 Financial Results ? Net sales of $84.6 million increased 9.0% year-over-year and 14.7% from prior quarter ? Backlog of $191 million; $273 million including confirmed orders representing the second highest level on record ? Net income of $4.9 million, or $0.50 per diluted share, increased 132.1% from prior quarter ? Completed acquisit

Financial Statements and Exhibits, Results of Operations and Financial Condition

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 OR 15(d) of The Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): November 8, 2021 NORTHWEST PIPE COMPANY (Exact name of registrant as specified in its charter) Oregon 0-27140 93-0557988 (State or other jurisdiction of incorporation) (Commission Fil

Incremental Amendment dated October 22, 2021 by and among Northwest Pipe Company, NWPC, LLC, Geneva Pipe and Precast Company, Park Environmental Equipment, LLC, certain other subsidiaries of Northwest Pipe Company, and Wells Fargo Bank, National Association, incorporated by reference to the Company’s Current Report on Form 8‑K, as filed with the Securities and Exchange Commission on October 28, 2021

Exhibit 10.1 Execution Copy INCREMENTAL AMENDMENT This INCREMENTAL AMENDMENT, dated as of October 22, 2021 (this ?Amendment?), is by and among NORTHWEST PIPE COMPANY, an Oregon corporation (?Administrative Borrower?), NWPC, LLC, a Delaware limited liability company (?NWPC?), GENEVA PIPE AND PRECAST COMPANY, a Utah corporation (?Geneva?), PARK ENVIRONMENTAL EQUIPMENT, LLC, a Texas limited liability

Current Report

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 OR 15(d) of The Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): October 22, 2021 NORTHWEST PIPE COMPANY (Exact name of registrant as specified in its charter) Oregon 0-27140 93-0557988 (State or other jurisdiction of incorporation) (Commission Fil

Northwest Pipe Company Announces Acquisition of ParkUSA Water transmission pipe leader acquires Texas-based water technology focused company for cash consideration of $87.4 million

Exhibit 99.1 MEDIA RELEASE FOR IMMEDIATE RELEASE October 5, 2021 Contact: Aaron Wilkins Chief Financial Officer Northwest Pipe Company 360-397-6294 ? [email protected] Northwest Pipe Company Announces Acquisition of ParkUSA Water transmission pipe leader acquires Texas-based water technology focused company for cash consideration of $87.4 million VANCOUVER, Washington: Northwest Pipe Company (Na

Current Report

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 OR 15(d) of The Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): October 5, 2021 NORTHWEST PIPE COMPANY (Exact name of registrant as specified in its charter) Oregon 0-27140 93-0557988 (State or other jurisdiction of incorporation) (Commission File

99.2 Presentation made available for reference in connection with the conference call to be held at 8:00 a.m. Pacific time on October 6, 2021

Exhibit 99.2

Membership Interest Purchase Agreement dated as of October 5, 2021 by and among Northwest Pipe Company, EBSR, LLC, the equity holders of EBSR, LLC, and Park Environmental Equipment, LLC, incorporated by reference to the Company’s Current Report on Form 8‑K, as filed with the Securities and Exchange Commission on October 6, 2021**

Exhibit 2.1 Execution Version MEMBERSHIP INTEREST PURCHASE AGREEMENT among NORTHWEST PIPE COMPANY and EBSR, LLC and MEMBERS OF EBSR, LLC and PARK ENVIRONMENTAL EQUIPMENT, LLC and EBSR, LLC, as Seller Representative dated as of October 5, 2021 TABLE OF CONTENTS Page ARTICLE I. Definitions 2 ARTICLE II. PURCHASE AND SALE 17 Section 2.01 Purchase and Sale 17 Section 2.02 Closing 17 Section 2.03 Closi

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-Q

Table of Contents UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-Q ? QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the quarterly period ended: June 30, 2021 or ? TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period from to Commission File Number: 0-27140 NORT

Financial Statements and Exhibits, Results of Operations and Financial Condition

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 OR 15(d) of The Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): August 4, 2021 NORTHWEST PIPE COMPANY (Exact name of registrant as specified in its charter) Oregon 0-27140 93-0557988 (State or other jurisdiction of incorporation) (Commission File

Northwest Pipe Company Announces Second Quarter 2021 Financial Results

Exhibit 99.1 Northwest Pipe Company Announces Second Quarter 2021 Financial Results ? Net sales of $73.8 million increased 5.5% year-over-year ? Strong backlog of $195 million; $234 million including confirmed orders representing the 12th consecutive quarter over $200 million ? Net income of $2.1 million or $0.21 per diluted share ? Completed refinancing to increase borrowing capacity to $100 mill

Credit Agreement dated June 30, 2021 by and among Wells Fargo Bank, National Association, Wells Fargo Securities, LLC, Northwest Pipe Company, NWPC, LLC, and Geneva Pipe and Precast Company, incorporated by reference to the Company’s Current Report on Form 8‑K, as filed with the Securities and Exchange Commission on July 7, 2021

Exhibit 10.1 Execution Copy CREDIT AGREEMENT dated as of June 30, 2021, by and among NORTHWEST PIPE COMPANY, NWPC, LLC and GENEVA PIPE AND PRECAST COMPANY, as Borrowers, the Lenders referred to herein, as Lenders, and WELLS FARGO BANK, NATIONAL ASSOCIATION, as Administrative Agent, Swingline Lender and Issuing Lender WELLS FARGO SECURITIES, LLC, as Sole Lead Arranger and Sole Bookrunner TABLE OF C

Entry into a Material Definitive Agreement, Termination of a Material Definitive Agreement, Financial Statements and Exhibits, Creation of a Direct Financial Obligation or an Obligation under an Off-Balance Sheet Arrangement of a Registrant

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 OR 15(d) of The Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): June 30, 2021 NORTHWEST PIPE COMPANY (Exact name of registrant as specified in its charter) Oregon 0-27140 93-0557988 (State or other jurisdiction of incorporation) (Commission File N

Guaranty and Security Agreement dated June 30, 2021 among Northwest Pipe Company, NWPC, LLC, Geneva Pipe and Precast Company, Permalok Corporation, Thompson Tank Holdings, Inc., WTG Holding U.S., Inc., Bolenco Corporation, and Wells Fargo Bank, National Association, incorporated by reference to the Company’s Current Report on Form 8‑K, as filed with the Securities and Exchange Commission on July 7, 2021

EX-10.2 3 ex261714.htm EXHIBIT 10.2 Exhibit 10.2 Execution Copy GUARANTY AND SECURITY AGREEMENT This GUARANTY AND SECURITY AGREEMENT (this “Agreement”), dated as of June 30, 2021, among the Persons listed on the signature pages hereof as “Grantors” and those additional entities that hereafter become parties hereto by executing the form of Joinder attached hereto as Annex 1 (each, a “Grantor” and c

Change in Control Agreement dated June 10, 2021 between Northwest Pipe Company and Miles Brittain, incorporated by reference to the Company’s Current Report on Form 8‑K/A, as filed with the Securities and Exchange Commission on June 11, 2021*

Exhibit 10.1 June 10, 2021 Miles Brittain Northwest Pipe Company, an Oregon corporation (the ?Company?), considers the establishment and maintenance of a sound and vital management to be essential to protecting and enhancing the best interests of the Company and its shareholders. In this connection, the Company recognizes that, as is the case with many publicly held corporations, the possibility o

Departure of Directors or Certain Officers; Election of Directors; Appointment of Certain Officers; Compensatory Arrangements of Certain Officers, Financial Statements and Exhibits

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K/A (Amendment No. 1) CURRENT REPORT Pursuant to Section 13 OR 15(d) of The Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): May 6, 2021 NORTHWEST PIPE COMPANY (Exact name of registrant as specified in its charter) Oregon 0-27140 93-0557988 (State or other jurisdiction of incorporation)

Financial Statements and Exhibits

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 OR 15(d) of The Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): June 10, 2021 NORTHWEST PIPE COMPANY (Exact name of registrant as specified in its charter) Oregon 0-27140 93-0557988 (State or other jurisdiction of incorporation) (Commission File N

Current Report

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 OR 15(d) of The Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): June 10, 2021 NORTHWEST PIPE COMPANY (Exact name of registrant as specified in its charter) oregon 0-27140 93-0557988 (State or other jurisdiction of incorporation) (Commission File N

99.1 2021 Annual Shareholder Meeting Presentation dated June 10, 2021

Exhibit 99.1

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM SD Specialized Disclosure Report NORTHWEST PIPE COMPANY (Exact name of registrant as specified in its charter)

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM SD Specialized Disclosure Report NORTHWEST PIPE COMPANY (Exact name of registrant as specified in its charter) OREGON 0-27140 93-0557988 (State or other jurisdiction of incorporation or organization) (Commission File Number) (IRS Employer Identification No.) 201 NE Park Plaza Drive, Suite 100 Vancouver, WA 98684 (Address

Departure of Directors or Certain Officers; Election of Directors; Appointment of Certain Officers; Compensatory Arrangements of Certain Officers, Financial Statements and Exhibits

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 OR 15(d) of The Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): May 6, 2021 NORTHWEST PIPE COMPANY (Exact name of registrant as specified in its charter) Oregon 0-27140 93-0557988 (State or other jurisdiction of incorporation) (Commission File Num

Quarterly Report - FORM 10-Q

Table of Contents UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-Q ? QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the quarterly period ended: March 31, 2021 or ? TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period from to Commission File Number: 0-27140 NOR

Financial Statements and Exhibits, Results of Operations and Financial Condition

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 OR 15(d) of The Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): May 3, 2021 NORTHWEST PIPE COMPANY (Exact name of registrant as specified in its charter) Oregon 0-27140 93-0557988 (State or other jurisdiction of incorporation) (Commission File Num

Northwest Pipe Company Announces First Quarter 2021 Financial Results

Exhibit 99.1 Northwest Pipe Company Announces First Quarter 2021 Financial Results ? Net sales of $72.3 million increased 4.9% year-over-year ? Strong backlog of $178 million; $210 million including confirmed orders representing the eleventh consecutive quarter over $200 million ? Net income of $2.2 million or $0.22 per diluted share VANCOUVER, Washington?May 3, 2021?Northwest Pipe Company (NASDAQ

- FORM DEF 14A

Table of Contents UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 14A Proxy Statement Pursuant to Section 14(a) of the Securities Exchange Act of 1934 (Amendment No. ) Filed by the Registrant ? Filed by a party other than the Registrant ? Check the appropriate box: ? Preliminary Proxy Statement ? Confidential, for Use of the Commission Only (as permitted by Rule 14

Financial Statements and Exhibits, Other Events

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 OR 15(d) of The Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): April 8, 2021 NORTHWEST PIPE COMPANY (Exact name of registrant as specified in its charter) Oregon 0-27140 93-0557988 (State or other jurisdiction of incorporation) (Commission File N

Form of Performance Share Unit Agreement, incorporated by reference to the Company’s Current Report on Form 8‑K, as filed with the Securities and Exchange Commission on March 19, 2021*

Exhibit 10.1 PERFORMANCE SHARE UNIT AGREEMENT This PERFORMANCE SHARE UNIT AGREEMENT (?Agreement?) is made and entered into as of March 18, 2021 (?Effective Date?) by and between Northwest Pipe Company (the ?Company?), and XXX (?Employee?) (collectively, ?the parties?). RECITALS The Company has determined that it would like to provide certain financial incentives to Employee in order to encourage c

Form of Restricted Stock Unit Agreement, incorporated by reference to the Company’s Current Report on Form 8‑K, as filed with the Securities and Exchange Commission on March 19, 2021*

Exhibit 10.2 NORTHWEST PIPE COMPANY RESTRICTED STOCK UNIT AGREEMENT 1. Grant. Northwest Pipe Company (the ?Company?) hereby grants you, XXX (the ?Employee?), in your position as XXX, an award of XXX Restricted Stock Units under the Company?s 2021 Long Term Incentive Grant (the ?2021 LTI Grant?), subject to all of the terms and conditions of this Agreement, the 2021 LTI Grant and the Company?s stoc

Departure of Directors or Certain Officers; Election of Directors; Appointment of Certain Officers; Compensatory Arrangements of Certain Officers, Financial Statements and Exhibits

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 OR 15(d) of The Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): March 18, 2021 NORTHWEST PIPE COMPANY (Exact name of registrant as specified in its charter) Oregon 0-27140 93-0557988 (State or other jurisdiction of incorporation) (Commission File

Subsidiaries of the Registrant, filed herewith

EXHIBIT 21.1 NORTHWEST PIPE COMPANY SUBSIDIARIES OF THE REGISTRANT As of December 31, 2020 Permalok Corporation, Missouri Thompson Tank Holdings, Inc., Oregon NWPC, LLC, Delaware WTG Holding U.S., Inc., California Bolenco Corporation, California NWPC de SLRC, S de RL de CV, Mexico NWPC de Mexico, S de RL de CV, Mexico Rio Co., S de RL de CV, Mexico Corporacion Californiana de Tuberias APS, S de RL

Annual Report - FORM 10-K

Table of Contents UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-K ? ANNUAL REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the fiscal year ended: December 31, 2020 or ? TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period from to Commission file number: 0-27140 NORTHWES

Financial Statements and Exhibits, Results of Operations and Financial Condition

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 OR 15(d) of The Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): March 3, 2021 NORTHWEST PIPE COMPANY (Exact name of registrant as specified in its charter) Oregon 0-27140 93-0557988 (State or other jurisdiction of incorporation) (Commission File N

Northwest Pipe Company Announces Fourth Quarter and Full Year 2020 Financial Results

Exhibit 99.1 Northwest Pipe Company Announces Fourth Quarter and Full Year 2020 Financial Results ? Annual net sales of $285.9 million increased 2.4% year-over-year ? Annual gross profit of $50.5 million increased 7.1% year-over-year ? Strong backlog of $167 million; $221 million including confirmed orders representing the tenth consecutive quarter over $200 million ? Annual net income of $1.93 pe

SCHEDULE 13G

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 13G Under the Securities Exchange Act of 1934 (Amendment No. 20 )* Northwest Pipe Co (Name of Issuer) Common Stock (Title of Class of Securities) 667746101 (CUSIP Number) December 31, 2020 (Date of Event Which Requires Filing of this Statement) Check the appropriate box to designate the rule pursuant to which this Sch

SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 Schedule 13G Under the Securities Exchange Act of 1934 (Amendment No.: 1)*

SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 Schedule 13G Under the Securities Exchange Act of 1934 (Amendment No.: 1)* Name of issuer: Northwest Pipe Co Title of Class of Securities: Common Stock CUSIP Number: 667746101 Date of Event Which Requires Filing of this Statement: December 31, 2020 Check the appropriate box to designate the rule pursuant to which this Schedule is filed: ☒ R

Departure of Directors or Certain Officers; Election of Directors; Appointment of Certain Officers; Compensatory Arrangements of Certain Officers, Financial Statements and Exhibits - FORM 8-K

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 OR 15(d) of The Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): December 9, 2020 NORTHWEST PIPE COMPANY (Exact name of registrant as specified in its charter) oregon 0-27140 93-0557988 (State or other jurisdiction of incorporation) (Commission Fil

Quarterly Report - FORM 10-Q

Table of Contents UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-Q ☒ QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the quarterly period ended: September 30, 2020 or ☐ TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period from to Commission File Number: 0-27140

Financial Statements and Exhibits, Results of Operations and Financial Condition - FORM 8-K

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 OR 15(d) of The Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): November 4, 2020 NORTHWEST PIPE COMPANY (Exact name of registrant as specified in its charter) oregon 0-27140 93-0557988 (State or other jurisdiction of incorporation) (Commission Fil

Northwest Pipe Company Announces Third Quarter 2020 Financial Results

Exhibit 99.1 Northwest Pipe Company Announces Third Quarter 2020 Financial Results • Gross profit of $15.6 million and gross profit margin of 20.1% • Strong backlog of $143 million; $231 million including confirmed orders representing the ninth consecutive quarter over $200 million • Net income of $0.73 per diluted share; adjusted net income of $0.78 per diluted share • Net sales of $77.6 million,

Northwest Pipe Company 201 NE Park Plaza Drive, Suite 100 Vancouver, Washington 98684

Northwest Pipe Company 201 NE Park Plaza Drive, Suite 100 Vancouver, Washington 98684 October 29, 2020 VIA EDGAR United States Securities and Exchange Commission Division of Corporation Finance 100 F Street, N.

Form of Indenture

Exhibit 4.4 NORTHWEST PIPE COMPANY INDENTURE Dated as of , 20 [], Trustee TABLE OF CONTENTS Page ARTICLE I. DEFINITIONS AND INCORPORATION BY REFERENCE 1 Section 1.1. Definitions. 1 Section 1.2. Other Definitions. 3 Section 1.3. Incorporation by Reference of Trust Indenture Act. 3 Section 1.4. Rules of Construction. 4 ARTICLE II. THE SECURITIES 4 Section 2.1. Issuable in Series. 4 Section 2.2. Esta

- FORM S-3

Table of Contents As filed with the Securities and Exchange Commission on October 23, 2020 Registration No.

Quarterly Report - FORM 10-Q

Table of Contents UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-Q ☒ QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the quarterly period ended: June 30, 2020 or ☐ TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period from to Commission File Number: 0-27140 NORT

Financial Statements and Exhibits, Results of Operations and Financial Condition

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 OR 15(d) of The Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): August 4, 2020 NORTHWEST PIPE COMPANY (Exact name of registrant as specified in its charter) OREGON 0-27140 93-0557988 (State or other jurisdiction of incorporation) (Commission File

Northwest Pipe Company Announces Second Quarter 2020 Financial Results

Exhibit 99.1 Northwest Pipe Company Announces Second Quarter 2020 Financial Results • Gross profit of $13.0 million increased 57.7% year-over-year • Net income of $0.61 per diluted share; adjusted net income of $0.45 per diluted share • Restarted production at the Company’s San Luis Río Colorado facility in June; all facilities are now operating through the COVID-19 pandemic • Settled insurance cl

Northwest Pipe Company Elects Amanda Kulesa to its Board of Directors Addition to the Board expected to enhance overall organizational development and leadership

Exhibit 99.1 MEDIA RELEASE FOR IMMEDIATE RELEASE – July 9, 2020 Contact: Aaron Wilkins Chief Financial Officer Northwest Pipe Company 360-397-6294 • [email protected] Northwest Pipe Company Elects Amanda Kulesa to its Board of Directors Addition to the Board expected to enhance overall organizational development and leadership VANCOUVER, Washington: Northwest Pipe Company (Nasdaq: NWPX), an ind

Departure of Directors or Certain Officers; Election of Directors; Appointment of Certain Officers; Compensatory Arrangements of Certain Officers, Financial Statements and Exhibits

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 OR 15(d) of The Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): July 7, 2020 NORTHWEST PIPE COMPANY (Exact name of registrant as specified in its charter) OREGON 0-27140 93-0557988 (State or other jurisdiction of incorporation) (Commission File Nu

Submission of Matters to a Vote of Security Holders

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 OR 15(d) of The Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): June 4, 2020 NORTHWEST PIPE COMPANY (Exact name of registrant as specified in its charter) OREGON 0-27140 93-0557988 (State or other jurisdiction of incorporation) (Commission File Nu

Regulation FD Disclosure, Financial Statements and Exhibits

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 OR 15(d) of The Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): June 4, 2020 NORTHWEST PIPE COMPANY (Exact name of registrant as specified in its charter) OREGON 0-27140 93-0557988 (State or other jurisdiction of incorporation) (Commission File Nu

99.1 2020 Annual Shareholder Meeting Presentation dated June 4, 2020

Exhibit 99.1

- FORM SD

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM SD Specialized Disclosure Report NORTHWEST PIPE COMPANY (Exact name of registrant as specified in its charter) OREGON 0-27140 93-0557988 (State or other jurisdiction of incorporation or organization) (Commission File Number) (IRS Employer Identification No.) 201 NE Park Plaza Drive, Suite 100 Vancouver, WA 98684 (Address

Quarterly Report - FORM 10-Q

Table of Contents UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-Q ☒ QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the quarterly period ended: March 31, 2020 or ☐ TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period from to Commission File Number: 0-27140 NOR

Financial Statements and Exhibits, Results of Operations and Financial Condition

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 OR 15(d) of The Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): May 7, 2020 NORTHWEST PIPE COMPANY (Exact name of registrant as specified in its charter) OREGON 0-27140 93-0557988 (State or other jurisdiction of incorporation) (Commission File Num

Northwest Pipe Company Announces First Quarter 2020 Financial Results

Exhibit 99.1 Northwest Pipe Company Announces First Quarter 2020 Financial Results • U.S. plants have been deemed essential and continue to operate amidst the COVID-19 pandemic • Gross profit of $9.6 million increased 45.8% year-over-year • Net income of $0.06 per diluted share; Adjusted net income of $0.33 per diluted share • Strong backlog of $170 million; $224 million including confirmed orders

Definitive Proxy Statement on Schedule 14A (filed on April 23, 2020)

Table of Contents UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 14A Proxy Statement Pursuant to Section 14(a) of the Securities Exchange Act of 1934 (Amendment No. ) Filed by the Registrant ☒ Filed by a party other than the Registrant ☐ Check the appropriate box: ☐ Preliminary Proxy Statement ☐ Confidential, for Use of the Commission Only (as permitted by Rule 14

Amendments to Articles of Incorporation or Bylaws; Change in Fiscal Year, Financial Statements and Exhibits

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 OR 15(d) of The Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): April 15, 2020 NORTHWEST PIPE COMPANY (Exact name of registrant as specified in its charter) OREGON 0-27140 93-0557988 (State or other jurisdiction of incorporation) (Commission File

First Amendment to the Third Amended and Restated Bylaws

Exhibit 3.1 FIRST Amendment to third amended and restated Bylaws of northwest pipe company (Adopted 4/15/2020) Article II, Sections 2.3, 2.4 and 2.10 of the Third Amended and Restated Bylaws of Northwest Pipe Company are hereby amended in their entirety and replaced with the following: 2.3 Place of Meetings; Remote Communication. Meetings of the shareholders shall be held at the principal business

Northwest Pipe Company Ordered to Temporarily Close Plant Operations in Mexico U.S. based plants continue to operate

Exhibit 99.1 MEDIA RELEASE FOR IMMEDIATE RELEASE – April 7, 2020 Contact: Aaron Wilkins Chief Financial Officer Northwest Pipe Company 360-397-6294 • [email protected] Northwest Pipe Company Ordered to Temporarily Close Plant Operations in Mexico U.S. based plants continue to operate VANCOUVER, Washington: Northwest Pipe Company (Nasdaq: NWPX), an industry leader of engineered pipeline systems f

Financial Statements and Exhibits, Other Events

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 OR 15(d) of The Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): April 7, 2020 NORTHWEST PIPE COMPANY (Exact name of registrant as specified in its charter) OREGON 0-27140 93-0557988 (State or other jurisdiction of incorporation) (Commission File N

Separation Agreement dated March 30, 2020 between Northwest Pipe Company and Robin Gantt, incorporated by reference to the Company’s Current Report on Form 8-K, as filed with the Securities and Exchange Commission on April 3, 2020

Exhibit 10.1 March 27, 2020 Robin Gantt Re: Confidential Employment Separation Agreement Dear Robin: As we discussed, you have notified Northwest Pipe Co. (the “Company”) that you wish to resign, and the Company has accepted your resignation from your full time role, effective March 31, 2020. Provided below in Part I (“Separation from Employment”) are details regarding your final pay and other emp

Change in Control Agreement dated April 1, 2020 between Northwest Pipe Company and Aaron Wilkins, incorporated by reference to the Company’s Current Report on Form 8‑K, as filed with the Securities and Exchange Commission on April 3, 2020*

Exhibit 10.2 April 1, 2020 Aaron Wilkins Northwest Pipe Company, an Oregon corporation (the “Company”), considers the establishment and maintenance of a sound and vital management to be essential to protecting and enhancing the best interests of the Company and its shareholders. In this connection, the Company recognizes that, as is the case with many publicly held corporations, the possibility of

Departure of Directors or Certain Officers; Election of Directors; Appointment of Certain Officers; Compensatory Arrangements of Certain Officers, Financial Statements and Exhibits

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 OR 15(d) of The Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): March 30, 2020 NORTHWEST PIPE COMPANY (Exact name of registrant as specified in its charter) OREGON 0-27140 93-0557988 (State or other jurisdiction of incorporation) (Commission File

Board of Directors of Northwest Pipe Company Elect William Yearsley to the Board Addition to the Board will further infrastructure and utilities insight.

Exhibit 99.1 MEDIA RELEASE FOR IMMEDIATE RELEASE – April 1, 2020 Contact: Aaron Wilkins Chief Financial Officer Northwest Pipe Company 360-397-6294 • [email protected] Board of Directors of Northwest Pipe Company Elect William Yearsley to the Board Addition to the Board will further infrastructure and utilities insight. VANCOUVER, Washington: Northwest Pipe Company (Nasdaq: NWPX), an industry le

Form of Performance Share Unit Agreement, incorporated by reference to the Company’s Current Report on Form 8‑K, as filed with the Securities and Exchange Commission on April 1, 2020*

Exhibit 10.1 PERFORMANCE SHARE UNIT AGREEMENT This PERFORMANCE SHARE UNIT AGREEMENT (“Agreement”) is made and entered into as of March 26, 2020 (“Effective Date”) by and between Northwest Pipe Company (the “Company”), and XXX (“Employee”) (collectively, “the parties”). RECITALS The Company has determined that it would like to provide certain financial incentives to Employee in order to encourage c

Departure of Directors or Certain Officers; Election of Directors; Appointment of Certain Officers; Compensatory Arrangements of Certain Officers, Financial Statements and Exhibits, Other Events

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 OR 15(d) of The Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): March 26, 2020 NORTHWEST PIPE COMPANY (Exact name of registrant as specified in its charter) OREGON 0-27140 93-0557988 (State or other jurisdiction of incorporation) (Commission File

Form of Restricted Stock Unit Agreement, incorporated by reference to the Company’s Current Report on Form 8‑K, as filed with the Securities and Exchange Commission on April 1, 2020*

Exhibit 10.2 NORTHWEST PIPE COMPANY RESTRICTED STOCK UNIT AGREEMENT 1. Grant. Northwest Pipe Company (the “Company”) hereby grants you, XXXX (the “Employee”), in your position as XXXX, an award of XXX Restricted Stock Units under the Company’s 2020 Long Term Incentive Grant (the “2020 LTI Grant”), subject to all of the terms and conditions of this Agreement, the 2020 LTI Grant and the Company’s st

Subsidiaries of the Registrant, filed herewith

EXHIBIT 21.1 NORTHWEST PIPE COMPANY SUBSIDIARIES OF THE REGISTRANT As of December 31, 2019 Permalok Corporation, Missouri Thompson Tank Holdings, Inc., Oregon NWPC, LLC, Delaware WTG Holding U.S., Inc., California Bolenco Corporation, California NWPC de SLRC, S de RL de CV, Mexico NWPC de Mexico, S de RL de CV, Mexico Rio Co., S de RL de CV, Mexico Corporacion Californiana de Tuberias APS, S de RL

NWPX / Northwest Pipe Co. 10-K - Annual Report - FORM 10-K

Table of Contents UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-K ☒ ANNUAL REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the fiscal year ended: December 31, 2019 or ☐ TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period from to Commission file number: 0-27140 NORTHWES

Description of Securities Registered Under Section 12 of the Securities Exchange Act of 1934

Exhibit 4.2 DESCRIPTION OF SECURITIES REGISTERED UNDER SECTION 12 OF THE SECURITIES EXCHANGE ACT OF 1934 Northwest Pipe Company (“Company”), has one class of securities registered under Section 12 of the Securities Exchange Act of 1934, as amended: common stock. The following description of our common stock and preferred stock is summarized from, and qualified in its entirety by reference to, our

Northwest Pipe Company Reports Strong Profitability and Backlog and Announces Fourth Quarter Conference Call

Exhibit 99.1 MEDIA RELEASE FOR IMMEDIATE RELEASE – March 2, 2020 Contact: Robin Gantt Chief Financial Officer Northwest Pipe Company 360-397-6325 • [email protected] Northwest Pipe Company Reports Strong Profitability and Backlog and Announces Fourth Quarter Conference Call Fourth Quarter Highlights • The Company achieved its highest quarterly gross profit since 2013, with significant increases fr

Financial Statements and Exhibits, Results of Operations and Financial Condition

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 OR 15(d) of The Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): March 2, 2020 NORTHWEST PIPE COMPANY (Exact name of registrant as specified in its charter) OREGON 0-27140 93-0557988 (State or other jurisdiction of incorporation) (Commission File N

NWPX / Northwest Pipe Co. / DIMENSIONAL FUND ADVISORS LP - SCHEDULE 13G/A Passive Investment

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 13G Under the Securities Exchange Act of 1934 (Amendment No. 19)* NORTHWEST PIPE CO (Name of Issuer) Common Stock (Title of Class of Securities) 667746101 (CUSIP Number) December 31, 2019 (Date of Event Which Requires Filing of this Statement) Check the appropriate box to designate the rule pursuant to which this Sche

NWPX / Northwest Pipe Co. / VANGUARD GROUP INC - SCHEDULE 13G Passive Investment

SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 Schedule 13G Under the Securities Exchange Act of 1934 Name of issuer: Northwest Pipe Co Title of Class of Securities: Common Stock CUSIP Number: 667746101 Date of Event Which Requires Filing of this Statement: December 31, 2019 Check the appropriate box to designate the rule pursuant to which this Schedule is filed: ☒ Rule 13d-1(b) ☐ Rule

Regulation FD Disclosure, Financial Statements and Exhibits

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 OR 15(d) of The Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): February 7, 2020 NORTHWEST PIPE COMPANY (Exact name of registrant as specified in its charter) OREGON 0-27140 93-0557988 (State or other jurisdiction of incorporation) (Commission Fil

Presentation made available in connection with the conference call to be held at 7:00 a.m. PST on February 7, 2020

Exhibit 99.1

Entry into a Material Definitive Agreement, Financial Statements and Exhibits, Creation of a Direct Financial Obligation or an Obligation under an Off-Balance Sheet Arrangement of a Registrant, Completion of Acquisition or Disposition of Assets

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 OR 15(d) of The Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): January 31, 2020 NORTHWEST PIPE COMPANY (Exact name of registrant as specified in its charter) OREGON 0-27140 93-0557988 (State or other jurisdiction of incorporation) (Commission Fil

Agreement and Plan of Merger dated as of January 31, 2020 among Northwest Pipe Company, Hatch Acquisition Corporation, Geneva Pipe Company, Inc., the Shareholders of Geneva Pipe Company, Inc., and Kurt Johnson, as Shareholder Representative (incorporated by reference to the Company’s Current Report on Form 8-K, as filed with the Securities and Exchange Commission on February 6, 2020)

Exhibit 2.1 AGREEMENT AND PLAN OF MERGER among NORTHWEST PIPE COMPANY and HATCH ACQUISITION CORPORATION and GENEVA PIPE COMPANY, INC. and THE SHAREHOLDERS OF GENEVA PIPE COMPANY, INC. and KURT JOHNSON, AS SHAREHOLDER REPRESENTATIVE dated as of January 31, 2020 TABLE OF CONTENTS Page ARTICLE I. DefinitionS 2 ARTICLE II. The Merger 15 Section 2.01 The Merger 15 Section 2.02 Closing 15 Section 2.03 C

Consent and Amendment No. 1 to Credit Agreement dated January 31, 2020 by and among Wells Fargo Bank, National Association, Northwest Pipe Company, and NWPC, LLC, incorporated by reference to the Company’s Current Report on Form 8-K, as filed with the Securities and Exchange Commission on February 6, 2020

Exhibit 10.1 CONSENT AND AMENDMENT NO. 1 TO CREDIT AGREEMENT THIS CONSENT AND AMENDMENT NO. 1 TO CREDIT AGREEMENT (this "Amendment") is entered into as of January 31, 2020, by and among WELLS FARGO BANK, NATIONAL ASSOCIATION, ("Lender"), NORTHWEST PIPE COMPANY, an Oregon corporation ("Administrative Borrower"), and NWPC, LLC, a Delaware limited liability company (f/k/a Ameron Water Transmission Gr

Northwest Pipe Company Announces Acquisition of Geneva Pipe Company, Inc. The leader in water transmission pipe acquired the Utah-based precast concrete manufacturer for $49.4 million

Exhibit 99.1 MEDIA RELEASE FOR IMMEDIATE RELEASE – February 3, 2020 Contact: Robin Gantt Chief Financial Officer Northwest Pipe Company 360-397-6325 • [email protected] Northwest Pipe Company Announces Acquisition of Geneva Pipe Company, Inc. The leader in water transmission pipe acquired the Utah-based precast concrete manufacturer for $49.4 million VANCOUVER, Washington: Northwest Pipe Company (

NWPX / Northwest Pipe Co. 10-Q - Quarterly Report - FORM 10-Q

Table of Contents UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-Q ☒ QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the quarterly period ended: September 30, 2019 or ☐ TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period from to Commission File Number: 0-27140

Northwest Pipe Company Reports Strong Operating Profitability and Announces Third Quarter Conference Call

Exhibit 99.1 MEDIA RELEASE FOR IMMEDIATE RELEASE – October 30, 2019 Contact: Robin Gantt Chief Financial Officer Northwest Pipe Company 360-397-6325 • [email protected] Northwest Pipe Company Reports Strong Operating Profitability and Announces Third Quarter Conference Call Quarterly Highlights • The Company achieved its highest quarterly operating results since 2014, with significant increases fr

Financial Statements and Exhibits, Results of Operations and Financial Condition

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 OR 15(d) of The Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): October 30, 2019 NORTHWEST PIPE COMPANY (Exact name of registrant as specified in its charter) OREGON 0-27140 93-0557988 (State or other jurisdiction of incorporation) (Commission Fil

Northwest Pipe Company Announces Robin Gantt’s Retirement as Senior Vice President and Chief Financial Officer

Exhibit 99.1 MEDIA RELEASE FOR IMMEDIATE RELEASE – October 9, 2019 Contact: Robin Gantt Chief Financial Officer Northwest Pipe Company 360-397-6325 • [email protected] Northwest Pipe Company Announces Robin Gantt’s Retirement as Senior Vice President and Chief Financial Officer VANCOUVER, Washington: Northwest Pipe Company (Nasdaq: NWPX), an industry leader of engineered welded steel pipe products

Departure of Directors or Certain Officers; Election of Directors; Appointment of Certain Officers; Compensatory Arrangements of Certain Officers, Financial Statements and Exhibits

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 OR 15(d) of The Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): October 8, 2019 NORTHWEST PIPE COMPANY (Exact name of registrant as specified in its charter) OREGON 0-27140 93-0557988 (State or other jurisdiction of incorporation) (Commission File

Departure of Directors or Certain Officers; Election of Directors; Appointment of Certain Officers; Compensatory Arrangements of Certain Officers

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K/A (Amendment No. 1) CURRENT REPORT Pursuant to Section 13 OR 15(d) of The Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): August 14, 2019 NORTHWEST PIPE COMPANY (Exact name of registrant as specified in its charter) OREGON 0-27140 93-0557988 (State or other jurisdiction of incorporati

Departure of Directors or Certain Officers; Election of Directors; Appointment of Certain Officers; Compensatory Arrangements of Certain Officers, Financial Statements and Exhibits

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 OR 15(d) of The Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): August 14, 2019 NORTHWEST PIPE COMPANY (Exact name of registrant as specified in its charter) OREGON 0-27140 93-0557988 (State or other jurisdiction of incorporation) (Commission File

Northwest Pipe Company Elects John Paschal to Board of Directors

Exhibit 99.1 MEDIA RELEASE FOR IMMEDIATE RELEASE – August 19, 2019 Contact: Robin Gantt Chief Financial Officer Northwest Pipe Company 360-397-6325 • [email protected] Northwest Pipe Company Elects John Paschal to Board of Directors VANCOUVER, Washington: Northwest Pipe Company (Nasdaq: NWPX), an industry leader of engineered welded steel pipe products for the water transmission market, announced

NWPX / Northwest Pipe Co. 10-Q - Quarterly Report - FORM 10-Q

Table of Contents UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-Q ☒ QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the quarterly period ended: June 30, 2019 or ☐ TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period from to Commission File Number: 0-27140 NORT

Northwest Pipe Company Reports Profitable Quarterly Results and Announces Second Quarter Conference Call

Exhibit 99.1 MEDIA RELEASE FOR IMMEDIATE RELEASE – August 5, 2019 Contact: Robin Gantt Chief Financial Officer Northwest Pipe Company 360-397-6325 • [email protected] Northwest Pipe Company Reports Profitable Quarterly Results and Announces Second Quarter Conference Call Quarterly Highlights • Net income per diluted share was $0.31, compared to a loss per diluted share of $0.59 in the second quart

Financial Statements and Exhibits, Results of Operations and Financial Condition

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 OR 15(d) of The Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): August 5, 2019 NORTHWEST PIPE COMPANY (Exact name of registrant as specified in its charter) OREGON 0-27140 93-0557988 (State or other jurisdiction of incorporation) (Commission File

NWPX / Northwest Pipe Co. 15-12G - - FORM 15-12G

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D. C. 20549 FORM 15 CERTIFICATION AND NOTICE OF TERMINATION OF REGISTRATION UNDER SECTION 12(g) OF THE SECURITIES EXCHANGE ACT OF 1934 OR SUSPENSION OF DUTY TO FILE REPORTS UNDER SECTIONS 13 AND 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934. Commission File Number: 0-27140 NORTHWEST PIPE COMPANY (Exact name of registrant as specified in i

NWPX / Northwest Pipe Co. 25 - - FORM 25

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D. C. 20549 FORM 25 NOTIFICATION OF REMOVAL FROM LISTING AND/OR REGISTRATION UNDER SECTION 12(b) OF THE SECURITIES EXCHANGE ACT OF 1934. Commission File Number: 0-27140 NORTHWEST PIPE COMPANY Nasdaq Global Select Market (Exact name of Issuer as specified in its charter, and name of Exchange where security is listed and/or registered) 201

NWPX / Northwest Pipe Co. 8-A12G/A - - FORM 8-A12G/A

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, DC 20549 FORM 8-A/A (Amendment No.

Termination of a Material Definitive Agreement, Material Modification to Rights of Security Holders, Notice of Delisting or Failure to Satisfy a Continued Listing Rule or Standard; Transfer of Listing

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 OR 15(d) of The Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): June 28, 2019 NORTHWEST PIPE COMPANY (Exact name of registrant as specified in its charter) OREGON 0-27140 93-0557988 (State or other jurisdiction of incorporation) (Commission File N

Departure of Directors or Certain Officers; Election of Directors; Appointment of Certain Officers; Compensatory Arrangements of Certain Officers, Submission of Matters to a Vote of Security Holders

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 OR 15(d) of The Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): June 20, 2019 NORTHWEST PIPE COMPANY (Exact name of registrant as specified in its charter) OREGON 0-27140 93-0557988 (State or other jurisdiction of incorporation) (Commission File N

Regulation FD Disclosure, Financial Statements and Exhibits

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 OR 15(d) of The Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): June 20, 2019 NORTHWEST PIPE COMPANY (Exact name of registrant as specified in its charter) OREGON 0-27140 93-0557988 (State or other jurisdiction of incorporation) (Commission File N

99.1 2019 Annual Shareholder Meeting Presentation dated June 20, 2019

Exhibit 99.1

NWPX / Northwest Pipe Co. SD - - FORM SD

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM SD Specialized Disclosure Report NORTHWEST PIPE COMPANY (Exact name of registrant as specified in its charter) OREGON 0-27140 93-0557988 (State or other jurisdiction of incorporation or organization) (Commission File Number) (IRS Employer Identification No.) 201 NE Park Plaza Drive, Suite 100 Vancouver, WA 98684 (Address

NWPX / Northwest Pipe Co. 10-Q Quarterly Report FORM 10-Q

Table of Contents UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-Q ☒ QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the quarterly period ended: March 31, 2019 or ☐ TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period from to Commission File Number: 0-27140 NOR

Financial Statements and Exhibits, Results of Operations and Financial Condition

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 OR 15(d) of The Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): May 8, 2019 NORTHWEST PIPE COMPANY (Exact name of registrant as specified in its charter) OREGON 0-27140 93-0557988 (State or other jurisdiction of incorporation) (Commission File Num

Northwest Pipe Company Reports Profitable Quarterly Results and Announces First Quarter Conference Call

Exhibit 99.1 MEDIA RELEASE FOR IMMEDIATE RELEASE – May 8, 2019 Contact: Robin Gantt Chief Financial Officer Northwest Pipe Company 360-397-6325 • [email protected] Northwest Pipe Company Reports Profitable Quarterly Results and Announces First Quarter Conference Call Quarterly Highlights • Net income per diluted share was $0.22, compared to a loss per diluted share of $0.20 in the first quarter of

NWPX / Northwest Pipe Co. FORM DEF 14A

Table of Contents UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 14A Proxy Statement Pursuant to Section 14(a) of the Securities Exchange Act of 1934 Filed by the Registrant ☒ Filed by a Party other than the Registrant ☐ Check the appropriate box: ☐ Preliminary Proxy Statement ☐ Confidential, for Use of the Commission Only (as permitted by Rule 14a-6(e)(2)) ☒ Defi

Other Events

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 OR 15(d) of The Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): April 18, 2019 NORTHWEST PIPE COMPANY (Exact name of registrant as specified in its charter) OREGON 0-27140 93-0557988 (State or other jurisdiction of incorporation) (Commission File

Form of Performance Share Unit Agreement, incorporated by reference to the Company’s Current Report on Form 8-K, as filed with the Securities and Exchange Commission on April 1, 2019*

Exhibit 10.1 PERFORMANCE SHARE UNIT AGREEMENT This PERFORMANCE SHARE UNIT AGREEMENT (“Agreement”) is made and entered into as of March 26, 2019 (“Effective Date”) by and between Northwest Pipe Company (the “Company”), and XXX (“Employee”) (collectively, “the parties”). RECITALS The Company has determined that it would like to provide certain financial incentives to Employee in order to encourage c

Form of Restricted Stock Unit Agreement, incorporated by reference to the Company’s Current Report on Form 8-K, as filed with the Securities and Exchange Commission on April 1, 2019*

Exhibit 10.2 NORTHWEST PIPE COMPANY RESTRICTED STOCK UNIT AGREEMENT 1. Grant. Northwest Pipe Company (the “Company”) hereby grants you, XXXX (the “Employee”), in your position as XXXX, an award of XXX Restricted Stock Units under the Company’s 2019 Long Term Incentive Grant (the “2019 LTI Grant”), subject to all of the terms and conditions of this Agreement, the 2019 LTI Grant and the Company’s st

Departure of Directors or Certain Officers; Election of Directors; Appointment of Certain Officers; Compensatory Arrangements of Certain Officers, Financial Statements and Exhibits

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 OR 15(d) of The Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): March 26, 2019 NORTHWEST PIPE COMPANY (Exact name of registrant as specified in its charter) OREGON 0-27140 93-0557988 (State or other jurisdiction of incorporation) (Commission File

Subsidiaries of the Registrant, filed herewith

EXHIBIT 21.1 NORTHWEST PIPE COMPANY SUBSIDIARIES OF THE REGISTRANT Permalok Corporation, Missouri Thompson Tank Holdings, Inc., Oregon North American Pipe Fabricators, Mexico NWPC, LLC, Delaware WTG Holding U.S., Inc., California Bolenco Corporation, California NOV Ameron de SLRC, S de RL de CV, Mexico NOV Ameron de Mexico, S de RL de CV, Mexico Rio Co., S de RL de CV, Mexico Corporacion Californi

NWPX / Northwest Pipe Co. FORM 10-K (Annual Report)

Table of Contents UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-K ☒ ANNUAL REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the fiscal year ended: December 31, 2018 or ☐ TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period from to Commission file number: 0-27140 NORTHWES

Financial Statements and Exhibits, Results of Operations and Financial Condition

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 OR 15(d) of The Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): March 13, 2019 NORTHWEST PIPE COMPANY (Exact name of registrant as specified in its charter) OREGON 0-27140 93-0557988 (State or other jurisdiction of incorporation) (Commission File

Northwest Pipe Company Reports Profitable Quarterly Results and Announces Fourth Quarter Conference Call

Exhibit 99.1 MEDIA RELEASE FOR IMMEDIATE RELEASE – March 13, 2019 Contact: Robin Gantt Chief Financial Officer Northwest Pipe Company 360-397-6325 • [email protected] Northwest Pipe Company Reports Profitable Quarterly Results and Announces Fourth Quarter Conference Call Quarterly Highlights • Net income from continuing operations per diluted share was $0.02, compared to a loss per diluted share o

NWPX / Northwest Pipe Co. / WILLIAM BLAIR INVESTMENT MANAGEMENT, LLC - SC 13G/A Passive Investment

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 13G* (Rule 13d-102) INFORMATION TO BE INCLUDED IN STATEMENTS FILED PURSUANT TO § 240.13d-1(b), (c), AND (d) AND AMENDMENTS THERETO FILED PURSUANT TO § 240.13d-2 (Amendment No. 3)* Northwest Pipe Company (Name of Issuer) Common Stock (Title of Class of Securities) 667746101 (CUSIP Number) 12/31/2018 (Date of Event Whic

NWPX / Northwest Pipe Co. / DIMENSIONAL FUND ADVISORS LP - SCHEDULE 13G/A Passive Investment

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 13G Under the Securities Exchange Act of 1934 (Amendment No. 18)* NORTHWEST PIPE CO (Name of Issuer) Common Stock (Title of Class of Securities) 667746101 (CUSIP Number) December 31, 2018 (Date of Event Which Requires Filing of this Statement) Check the appropriate box to designate the rule pursuant to which this Sche

NWPX / Northwest Pipe Co. FORM 10-Q (Quarterly Report)

Table of Contents UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D. C. 20549 FORM 10-Q ☒ QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the quarterly period ended: September 30, 2018 or ☐ TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period from to Commission File Number: 0-2714

NORTHWEST PIPE COMPANY

Exhibit 99.1 NEWS RELEASE FOR IMMEDIATE RELEASE November 7, 2018 Northwest Pipe Company Reports Improved Third Quarter Results and Announces Conference Call Quarterly Highlights • Net income from continuing operations per diluted share was $2.86, compared to a prior quarter net loss of $0.59 per diluted share and net loss of $0.16 per diluted share in the third quarter of 2017 • Excluding one-time

Financial Statements and Exhibits, Results of Operations and Financial Condition

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 Date of Report (Date of earliest event reported): November 7, 2018 NORTHWEST PIPE COMPANY (Exact name of registrant as specified in its charter) OREGON 0-27140 93-0557988 (State or other jurisdiction of incorporation) (Commission Fil

Guaranty and Security Agreement dated October 25, 2018 among Northwest Pipe Company, Ameron Water Transmission Group, LLC, Permalok Corporation, Thompson Tank Holdings, Inc., WTG Holding U.S., Inc., Bolenco Corporation, and Wells Fargo, National Association, incorporated by reference to the Company’s Current Report on Form 8-K, as filed with the Securities and Exchange Commission on October 31, 2018

Exhibit 10.2 GUARANTY AND SECURITY AGREEMENT This GUARANTY AND SECURITY AGREEMENT (this "Agreement"), dated as of October 25, 2018, among the Persons listed on the signature pages hereof as "Grantors" and those additional entities that hereafter become parties hereto by executing the form of Joinder attached hereto as Annex 1 (each, a "Grantor" and collectively, the "Grantors"), and WELLS FARGO BA

Credit Agreement dated October 25, 2018 by and among Wells Fargo Bank, National Association, Northwest Pipe Company, and Ameron Water Transmission Group, LLC, incorporated by reference to the Company’s Current Report on Form 8-K, as filed with the Securities and Exchange Commission on October 31, 2018

Exhibit 10.1 CREDIT AGREEMENT by and among WELLS FARGO BANK, NATIONAL ASSOCIATION, as Lender, NORTHWEST PIPE COMPANY, and AMERON WATER TRANSMISSION GROUP, LLC as Borrowers Dated as of October 25, 2018 TABLE OF CONTENTS Page 1. DEFINITIONS AND CONSTRUCTION. 1 1.1. Definitions 1 1.2. Accounting Terms 42 1.3. Code 42 1.4. Construction 43 1.5. Time References 43 1.6. Schedules and Exhibits 43 2. LOANS

Entry into a Material Definitive Agreement, Financial Statements and Exhibits, Creation of a Direct Financial Obligation or an Obligation under an Off-Balance Sheet Arrangement of a Registrant

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 OR 15(d) of The Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): October 25, 2018 NORTHWEST PIPE COMPANY (Exact name of registrant as specified in its charter) OREGON 0-27140 93-0557988 (State or other jurisdiction of incorporation) (Commission Fil

UNAUDITED PRO FORMA CONDENSED COMBINED FINANCIAL INFORMATION

Exhibit 99.2 UNAUDITED PRO FORMA CONDENSED COMBINED FINANCIAL INFORMATION Northwest Pipe Company (the “Company”) acquired Ameron Water Transmission Group, LLC (“Ameron”) on July 27, 2018 for total consideration of approximately $38.3 million, subject to a post-closing adjustment based on changes in net working capital. The Company financed the acquisition with cash on hand. The following unaudited