BayCorp Announces Successful Completion of First Natural Gas Production Well Under Joint Development Agreement with Sonerra.

PORTSMOUTH, N.H. -- Nacogdoches Gas, LLC, a wholly-owned subsidiary of BayCorp Holdings, Ltd. ("BayCorp") (AMEX: MWH), today announced that it has completed the first natural gas production well in Nacogdoches County, Texas under its development agreement with Sonerra Resources Corporation ("Sonerra") announced on January 7, 2005. Drilled as a horizontal well with a single 6,586 foot lateral, the well was placed into production in early January at a cost of approximately $3 million and has been producing natural gas at a rate of approximately 2.5 million cubic feet per day. Under the agreement with Sonerra, Nacogdoches Gas will have a 90% working interest in this well until Nacogdoches Gas's investment is recovered. Once Nacogdoches Gas recovers its investment and other operating costs associated with the well, it will have a 50% working interest.

About BayCorp

BayCorp Holdings, Ltd. is an unregulated holding company incorporated in Delaware. BayCorp currently has five wholly owned subsidiaries including Great Bay Power Marketing, Inc., which purchases and markets power on the open market, BayCorp Ventures, LLC, which serves as a vehicle for the Company's investments, Great Bay Hydro Corporation which was formed for the purpose of holding the generating facilities in Vermont acquired from the Vermont Electric Division of Citizens Communications Company on April 1, 2004, Nacogdoches Power, LLC, which was formed for the purpose of holding the Sterne Power Project and Nacogdoches Gas, LLC, which was formed for the purpose of holding natural gas and oil assets. As of May 1, 2004, BayCorp had a majority interest in HoustonStreet Exchange, Inc., which operates HoustonStreet.com, an independent internet-based crude oil and refined products trading exchange. Prior to May 1, 2004, BayCorp held a minority interest in HoustonStreet.

Forward Looking Statements

Any statements contained in this release regarding the Company's goals, strategies, and expectations are "forward-looking statements." Such statements include those addressing the Company's participation in the future development of natural gas and oil wells, Sonerra's continued development of natural gas and oil wells, and the recovery of investment and other operating costs associated with the well. Factors that may affect future results include the actual cost of the wells, the success in well drilling and development and the amount of production from the wells, the period over which the wells will be developed, Sonerra Resources, Inc.'s continued operation and its success in oil and gas well development, on which Nacogdoches Gas, LLC is substantially dependant and the ability of BayCorp or its subsidiaries to acquire financing for the development of future wells. No assurances can be given that the results in any forward-looking statements will be achieved and actual results could differ materially. Please review reports filed by BayCorp with the Securities and Exchange Commission for information and factors that could affect the Company's business.