Filed pursuant to Rule 425 under the

Securities Act of 1933, as amended, and

deemed filed under Rule 14a-12 under the

Securities Exchange Act of 1934, as amended

Filer: SJW Group

Commission File No.: 1-08966

Subject Company: Connecticut Water Service, Inc.

Commission File No.: 0-08084

From: Tang, John

Sent: Friday, May 18, 2018 6:39 PM

To: Tang, John

Subject: SJW Group - Connecticut Water Merger Update (5/18/2018)

Dear Elected Officials, Staff and Community Leaders,

I write to provide an update on SJW Group’s merger of equals with Connecticut Water. We are excited about the progress we have made towards completing our merger of equals including:

Our combined company will have the scale, geographic diversity, and financial strength to deliver benefits to all stakeholders, including everyone we serve here in San Jose. Specifically, the merger of equals includes the following commitments from us to our communities:

As you know, California Water Service Group (Cal Water) has initiated a hostile takeover attempt of our company after their non-binding indication of interest was carefully considered and unanimously rejected by SJW Group’s Boards of Directors. Cal Water is now resorting to contacting our employees, union representatives, shareholders, and community and elected leaders to pitch what we believe to be an inferior and non-binding indication of interest that will inevitably result in job losses and could affect water quality and service.

In a recent letter sent to you by San Jose Water employees, they expressed their fear that Cal Water will cut their jobs. They don’t want the “fair severance,” Cal Water indicated they would offer (Cupertino Today, April 5, 2018). They believe in their company’s more than 150 years of service to our community and they are proud to continue that tradition of service.

Cal Water is suggesting, without evidence, that their offer would lead to potential cost-savings for customers. If not from job losses, where will these cost savings come from?

Additionally, we are concerned about Cal Water’s ability to operate a large scale contiguous water system when considering the average size of their disparate water system is approximately 10% the size of ours. This consideration, coupled with the loss of institutional knowledge via the potential elimination of jobs, will no doubt impact Cal Water’s ability to deliver safe, high quality, and reliable water service to the community.

Despite the distraction caused by Cal Water’s attempt to undermine our value-creating merger of equals, we remain committed to keeping you informed of the latest developments. Should you have any questions, please reach me directly at 408-234-6691.

Best,

John

* * * * * *

Forward Looking Statements

This document contains forward-looking statements within the meaning of the Private Litigation Reform Act of 1995, as amended. Some of these forward-looking statements can be identified by the use of forward-looking words such as “believes,” “expects,” “may,” “will,” “should,” “seeks,” “approximately,” “intends,” “plans,” “estimates,” “projects,” “strategy,” or “anticipates,” or the negative of those words or other comparable terminology.

The accuracy of such statements is subject to a number of risks, uncertainties and assumptions including, but not limited to, the following factors: (1) the risk that the conditions to the closing of the transaction are not satisfied, including the risk that required approvals from the shareholders of Connecticut Water or the shareholders of SJW Group for the transaction are not obtained; (2) the risk that the regulatory approvals required for the transaction are not obtained, or that in order to obtain such regulatory approvals, conditions are imposed that adversely affect the anticipated benefits from the proposed transaction or cause the parties to abandon the proposed transaction; (3) the risk that the anticipated tax treatment of the transaction is not obtained; (4) the effect of water, utility, environmental and other governmental policies and regulations; (5) litigation relating to the transaction; (6) uncertainties as to the timing of the consummation of the transaction and the ability of each party to consummate the transaction; (7) risks that the proposed transaction disrupts the current plans and operations of Connecticut Water or SJW Group; (8) the ability of Connecticut Water and SJW Group to retain and hire key personnel; (9) competitive responses to the proposed transaction; (10) unexpected costs, charges or expenses resulting from the transaction; (11) potential adverse reactions or changes to business relationships resulting from the announcement or completion of the transaction; (12) the combined companies’ ability to achieve the growth prospects and synergies expected from the transaction, as well as delays, challenges and expenses associated with integrating the combined companies’ existing businesses; and (13) legislative and economic developments. These risks, as well as other risks associated with the proposed transaction, are more fully discussed in the joint proxy statement/prospectus that is included in the Registration Statement on Form S-4 that has been filed with the Securities and Exchange Commission (“SEC”) in connection with the proposed transaction.

In addition, actual results are subject to other risks and uncertainties that relate more broadly to SJW Group’s overall business, including those more fully described in SJW Group’s filings with the SEC, including its annual report on Form 10-K for the fiscal year ended December 31, 2017 and its quarterly report on Form 10-Q for the fiscal quarter ended March 31, 2018, and Connecticut Water’s overall business and financial condition, including those more fully described in Connecticut Water’s filings with the SEC, including its annual report on Form 10-K for the fiscal year ended December 31, 2017 and its quarterly report on Form 10-Q for the fiscal quarter ended March 31, 2018. Forward looking statements are not guarantees of performance, and speak only as of the date made, and neither SJW Group or its management nor Connecticut Water or its management undertakes any obligation to update or revise any forward-looking statements.

Additional Information and Where to Find It

In connection with the proposed transaction between SJW Group and Connecticut Water, on April 25, 2018, SJW Group filed with the SEC a Registration Statement on Form S-4 that includes a joint proxy statement of SJW Group and Connecticut Water that also constitutes a prospectus of SJW Group. These materials are not yet final and will be amended. SJW Group and Connecticut Water may also file other documents with the SEC regarding the proposed transaction. This document is not a substitute for the joint proxy statement/prospectus, Form S-4 or any other document which SJW Group or Connecticut Water may file with the SEC. INVESTORS AND SECURITY HOLDERS OF SJW GROUP AND CONNECTICUT WATER ARE URGED TO READ THE REGISTRATION STATEMENT, THE JOINT PROXY STATEMENT/PROSPECTUS AND ALL OTHER RELEVANT DOCUMENTS THAT ARE FILED OR WILL BE FILED WITH THE SEC, AS WELL AS ANY AMENDMENTS OR SUPPLEMENTS TO THESE DOCUMENTS, CAREFULLY AND IN THEIR ENTIRETY BECAUSE THEY CONTAIN OR WILL CONTAIN IMPORTANT INFORMATION ABOUT THE PROPOSED TRANSACTION AND RELATED MATTERS. Investors and security holders may obtain free copies of the Form S-4 and the joint proxy statement/prospectus and other documents filed with the SEC by SJW Group and Connecticut Water through the website maintained by the SEC at www.sec.gov. Copies of documents filed with the SEC by SJW Group are available free of charge on SJW Group’s investor relations website at https://sjwgroup.com/investor_relations. Copies of documents filed with the SEC by Connecticut Water are available free of charge on Connecticut Water’s investor relations website at https://ir.ctwater.com/.

No Offer or Solicitation

This communication is for informational purposes only and is not intended to and does not constitute an offer to sell, or the solicitation of an offer to subscribe for or buy, or a solicitation of any vote or approval in any jurisdiction, nor shall there be any sale, issuance or transfer of securities in any jurisdiction in which such offer, sale or solicitation would be unlawful prior to registration or qualification under the securities laws of any such jurisdiction. No offer of securities shall be made except by means of a prospectus meeting the requirements of Section 10 of the Securities Act of 1933, as amended, and otherwise in accordance with applicable law.

Participants in the Solicitation

SJW Group, Connecticut Water and certain of their respective directors and officers, and other members of management and employees, may be deemed to be participants in the solicitation of proxies from the holders of SJW Group and Connecticut Water securities in respect of the proposed transaction. Information regarding SJW Group’s directors and officers is available in SJW Group’s annual report on Form 10-K for the fiscal year ended December 31, 2017 and its proxy statement for its 2018 annual meeting dated March 6, 2018, which are filed with the SEC. Information regarding Connecticut Water’s directors and officers is available in Connecticut Water’s annual report on Form 10-K for the fiscal year ended December 31, 2017, and its proxy statement for its 2018 annual meeting dated April 6, 2018, which are filed with the SEC. Investors may obtain additional information regarding the interest of such participants by reading the Form S-4 and the joint proxy statement/prospectus and other documents filed with the SEC by SJW Group and Connecticut Water. These documents are available free of charge from the sources indicated above.