374Water Inc.

Item 5.03. Amendments to Articles of Incorporation or Bylaws; Change in Fiscal Year. On September 30, 2026, 374Water Inc. (the “Company”) filed a certificate of amendment to its amended and restated certificate of incorporation (the “Charter Amendment”) with the Secretary of State of the State of Delaware to (i) decrease the number of authorized shares of common stock of the Company from 1,000,000,000 shares to 75,000,000 shares and (ii) amend and restate Article EIGHT, Section A of the Company’s certificate of incorporation relating to the personal liability of directors and officers, in order to conform such provision to Section 102(b)(7) of the General Corporation Law of the State of Delaware (the “DGCL”). As further described under Item 5.07 below, the proposals for these amendments were approved by the Company’s stockholders at the Annual Meeting (as defined below). A copy of the Charter Amendment, which became effective upon its filing with the Secretary of State of the State of Delaware, is attached as Exhibit 3.1 to this Current Report on Form 8-K and is incorporated by reference in this Item 5.03. The foregoing description of the amendments effected by the Charter Amendment does not purport to be complete and is qualified in its entirety by reference to the full text of the Charter Amendment filed as Exhibit 3.1 hereto.

Item 5.07. Submission of Matters to a Vote of Security Holders. On September 18, 2026, the Company convened its 2026 Annual Meeting of Stockholders (the “Annual Meeting”) as a virtual-only meeting, as previously disclosed in the Company’s definitive proxy statement on Schedule 14A filed with the U.S. Securities and Exchange Commission on August 25, 2026 (the “2026 Proxy Statement”). At the Annual Meeting, the Company’s Inspector of Election reported that a quorum was not present. Pursuant to Section 1.4 of the Company’s Amended and Restated Bylaws, the chairman of the Annual Meeting adjourned the Annual Meeting to reconvene on September 25, 2026. The Annual Meeting reconvened on September 25, 2026, at which a quorum was present. As of July 31, 2026, the record date for the Annual Meeting, there were 17,493,924 outstanding shares of the Company’s common stock. The Company’s stockholders voted on the following matters at the Annual Meeting, which are described in detail in the 2026 Proxy Statement: (i) to elect six directors, James Pawloski, Marc Deshusses, Richard Davis, Bradley Freels, Stephen McKnight and Charles Weiser, to serve on the Company’s Board of Directors until the 2027 Annual Meeting of Stockholders or until successors have been duly elected and qualified (“Proposal 1”), (ii) to approve an amendment to the Company’s Certificate of Incorporation, as amended, to decrease the number of authorized shares of common stock of the Company from 1,000,000,000 shares to 75,000,000 shares (“Proposal 2”), (iii) to approve an amendment to the Company’s Certificate of Incorporation to amend and restate Article EIGHT, Section A relating to the personal liability of directors and officers, in order to conform such provision to Section 102(b)(7) of the DGCL (“Proposal 3”), and (iv) to ratify the appointment of Cherry Bekaert LLP as the Company’s independent registered public accounting firm for the fiscal year ending December 31, 2026 (“Proposal 4”). The Company’s stockholders approved the director nominees recommended for election in Proposal 1 at the Annual Meeting. The Company’s stockholders voted for directors as follows: Votes For Votes Against Votes Abstaining Broker Non-Votes ────────────────────────────────────────────────────────────────────────────────────────────────── James Pawloski 5,790,072 3,279,926 80,296 Marc Deshusses 5,851,090 3,263,577 35,627 Richard Davis 5,574,069 2,821,615 754,610 Bradley Freels 7,612,623 776,946 760,725 Stephen McKnight 7,612,633 783,051 754,610 Charles Weiser 8,170,674 946,660 32,960 The Company’s stockholders approved Proposal 2. The votes cast at the Annual Meeting were as follows: Votes For Votes Against Votes Abstaining Broker Non-Votes ────────────────────────────────────────────────────────────────────────────────────────────────────────────────── 9,073,279 71,377 5,638 The Company’s stockholders approved Proposal 3. The votes cast at the Annual Meeting were as follows: Votes For Votes Against Votes Abstaining Broker Non-Votes ─────────────────────────────────────────────────────────────────────────────────────────────────────────────────── 8,874,279 266,525 9,490 The Company’s stockholders approved Proposal 4. The votes cast at the Annual Meeting were as follows: Votes For Votes Against Votes Abstaining Broker Non-Votes ───────────────────────────────────────────────────────────────────────────────────────────────────────────────── 9,138,772 5,013 6,509