California Water Service Group (NYSE: CWT) adds Huntington to $350M ATM syndicate

Rhea-AI Filing Summary

California Water Service Group amended its equity distribution agreement to reflect the addition of Huntington Securities, Inc. as a Manager and the prior termination of Janney Montgomery Scott LLC for itself. The prospectus supplement covers the sale of common stock with an aggregate offering price up to $350,000,000.

The amendment is dated May 1, 2026; the Original Prospectus Supplement is dated May 14, 2025. The company’s common stock trades on the NYSE under the symbol CWT (last reported sale price $42.24 on April 30, 2026).

Insights

Capital Markets Counsel

Amendment updates distribution agents for an existing at‑the‑market program; economics unchanged.

The filing records a change in the syndicate: Janney withdrew as a Manager on Feb 27, 2026 and Huntington was added on May 1, 2026 under an amended Equity Distribution Agreement tied to an ATM program with an aggregate capacity of $350,000,000.

Operational impact is procedural: the amendment reallocates selling/placement capability among dealers. Timing and usage of the program remain at management’s discretion; prospectus risk references and distribution mechanics persist as previously disclosed.

Key Figures

Aggregate offering capacity: $350,000,000 Last reported sale price: $42.24 per share Prospectus Supplement date: May 14, 2025 +2 more

5 metrics

Aggregate offering capacity $350,000,000 aggregate offering price stated in prospectus supplement

Last reported sale price $42.24 per share NYSE last reported sale price as of April 30, 2026

Prospectus Supplement date May 14, 2025 date of the original Prospectus Supplement referenced

Janney termination date February 27, 2026 date Janney terminated its role as Manager

Amendment / Huntington addition date May 1, 2026 date Huntington was added and amendment executed

Key Terms

Equity Distribution Agreement, Manager, Forward Purchaser, aggregate offering price

4 terms

Equity Distribution Agreement financial

"relating to the sale of shares of our common stock"

An equity distribution agreement is a formal plan between a company and financial institutions to sell newly issued shares of the company's stock to investors over a period of time. It helps the company raise money gradually, similar to filling a container with water in stages, rather than all at once. For investors, it provides an organized way to buy shares and can influence the stock's supply and price.

Manager financial

"each, a “Manager” and, together, the “Managers”"

Forward Purchaser financial

"each of Robert W. Baird..., each as forward purchaser"

A forward purchaser is an investor or firm that signs an agreement to buy a security or asset at a set price on a specified future date, similar to pre-ordering a product today to receive it later. It matters to investors because the contract locks in a future purchase price and creates a binding commitment that can change a company’s future ownership, available shares, or cash flow; if market prices move, the forward purchaser’s gain or loss is determined by that pre-agreed price rather than current market swings.

aggregate offering price regulatory

"Having an Aggregate Offering Price of up to $350,000,000"

The aggregate offering price is the total dollar amount that will be raised if all the securities in an offering are sold at the stated offering price, before fees or expenses are taken out. Investors use it to gauge the size of the fundraising and its potential effects—such as how much cash the company will get and how much existing ownership might be reduced—similar to totaling every item’s price in a shopping cart to see the full bill.

Filed Pursuant to Rule 424(b)(5)

Registration No. 333-287273

SUPPLEMENT

To Prospectus Supplement dated May 14, 2025

(To Prospectus dated May 14, 2025) 

California Water Service Group

Common Stock

Having an Aggregate Offering Price of up to $350,000,000

This supplement amends, supplements or modifies certain information contained in the prospectus supplement, dated May 14, 2025 (the “Prospectus Supplement”), and the accompanying prospectus, dated May 14, 2025 (the “Base Prospectus,” and together with the Prospectus Supplement, any supplement thereto, and the documents deemed incorporated by reference in each, the “Prospectus”), which relate to the offer and sale of shares of our common stock, par value $0.01 per share (“our common stock”), pursuant to the Equity Distribution Agreement (as defined below). Capitalized terms used and not defined herein shall have the meanings ascribed to such terms in the Prospectus Supplement.

You should carefully read the entire Prospectus and this supplement before investing in our common stock. This supplement should be read in conjunction with the Prospectus, and is qualified by reference thereto, except to the extent that the information herein amends or supersedes the information contained in the Prospectus. This supplement is not complete without, and may only be delivered or utilized in connection with, the Prospectus and any future amendments or supplements thereto.

On May 14, 2025, we entered into an equity distribution agreement (the “Original Equity Distribution Agreement”) with Robert W. Baird & Co. Incorporated, BofA Securities, Inc., Morgan Stanley & Co. LLC, Wells Fargo Securities, LLC, Janney Montgomery Scott LLC, RBC Capital Markets, LLC, Blaylock Van, LLC and Samuel A. Ramirez & Company, Inc., each as sales agent and, if applicable, as forward seller (in any such capacity, each, a “Manager” and, together, the “Managers”), and each of Robert W. Baird & Co. Incorporated, Bank of America, N.A., Morgan Stanley & Co. LLC, Wells Fargo Bank, National Association and Royal Bank of Canada, each as forward purchaser (in such capacity, each a “Forward Purchaser” and together the “Forward Purchasers”), relating to the sale of shares of our common stock, having an aggregate gross sales price of up to $350,000,000.

This supplement is being filed to reflect that, on February 27, 2026, Janney Montgomery Scott LLC (“Janney”) terminated the Original Equity Distribution Agreement with respect to itself as Manager, and on May 1, 2026, we added Huntington Securities, Inc. (“Huntington”) as an additional Manager under the Original Equity Distribution Agreement. In connection with the addition of Huntington as Manager, we entered into an amendment, dated May 1, 2026, to the Original Equity Distribution Agreement (as amended, the “Amended Equity Distribution Agreement”). Accordingly, each reference to the term “Managers” in the Prospectus Supplement is hereby amended to include Huntington and remove Janney, and each reference to the term “Equity Distribution Agreement” is hereby amended to refer to the Amended Equity Distribution Agreement.

Our common stock is listed on the New York Stock Exchange (“NYSE”) under the symbol “CWT.” On April 30, 2026, the last reported sale price of our common stock on the NYSE was $42.24 per share.

Investing in our common stock involves risks. See “Risk Factors” beginning on page S-6 of the Prospectus Supplement and page 2 of the Base Prospectus and in the documents incorporated by reference into the Prospectus for a description of various risks you should consider in evaluating an investment in the shares. 

Neither the Securities and Exchange Commission nor any state securities commission has approved or disapproved of these securities or passed upon the adequacy or accuracy of this prospectus supplement or the accompanying prospectus. Any representation to the contrary is a criminal offense. 

Baird BofA Securities Morgan Stanley Wells Fargo Securities Huntington  Capital Markets RBC Capital Markets

Blaylock Van, LLC Ramirez & Co., Inc.

The date of this supplement is May 1, 2026.

FAQ

What does the California Water Service Group (CWT) prospectus supplement change?

It updates the dealer group by removing Janney and adding Huntington as a Manager. The amendment dated May 1, 2026 modifies references to the Equity Distribution Agreement in the May 14, 2025 prospectus supplement.

How large is the equity program referenced in the CWT supplement?

The Equity Distribution Agreement permits sales of common stock with an aggregate offering price up to $350,000,000. This is stated in the prospectus supplement and remains the documented program capacity.

Will California Water Service Group receive proceeds from these stock sales?

Sales under the Equity Distribution Agreement are described as the offer and sale of common stock; the prospectus contemplates issuer sales. The filing does not change the proceeds treatment disclosed in the May 14, 2025 prospectus supplement.

When did the Manager changes occur for the Equity Distribution Agreement?

Janney terminated its role as Manager on February 27, 2026; Huntington was added and the amendment executed on May 1, 2026. The prospectus supplement reflects these dates verbatim.

What ticker and recent price are disclosed in the supplement for CWT?

The company’s common stock trades on the NYSE under the symbol CWT. The last reported sale price stated is $42.24 per share on April 30, 2026.