Somach Simmons and Dunn, Attorneys at Law Somach Simmons & Dunn | Attorneys at Law

Areas

Education

  • University of the Pacific, McGeorge School of Law (J.D., 2010)
  • California State University, Sacramento (M.P.P.A., 2001)
  • University of California, Santa Barbara (B.A., 1995)

Selected Admissions

  • California
  • Washington

Spotlight

Read the full transcript from Aaron’s September 2020 virtual presentation for GRA’s Third Annual Western Groundwater Congress. “SGMA is complicated, groundwater adjudications can be complicated, but we’ve identified four key issues to focus on when determining whether the SGMA process has run its course and it is time to adjudicate.”

Aaron A. Ferguson
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LinkedIn Bio

Aaron Ferguson’s expertise in water law is the result of a unique combination of working on complex water law issues coupled with previous careers as a water supply analyst and a regulatory affairs specialist. He provides a well-rounded vision on the water issues that face his clients.

Aaron helps clients understand and protect their water rights, maximize the value of their water supplies, and achieve their water supply planning objectives. He regularly advises landowners and public agencies with respect to the existence and scope of their water rights and memorializes his findings in water right opinions. Recently, he helped a client challenge a State Water Resources Control Board (State Water Board) Cease and Desist Order determining the client does not possess a riparian right to a specific parcel of land.

Aaron combines his knowledge of water law with his experience in water supply planning to assist clients in the development of water supply plans such as Urban Water Management Plans and Water Supply Assessments consistent with relevant legal requirements. He applies these skills to help clients develop Groundwater Sustainability Plans (GSPs) under the Sustainable Groundwater Management Act (SGMA) and continues to assist these clients with the implementation of their GSPs. He also provides advice to public agencies on Proposition 218 compliance for imposition of water rates. He has advised clients in the development and adoption of groundwater management fees pursuant to the SGMA.

Aaron applies his expertise in water rights law to deliver efficient solutions to complex water resources challenges facing his clients, including negotiating and drafting facility capacity agreements and surface water and groundwater transfer agreements. He also assists clients in developing creative solutions to regulations proposed by administrative agencies, including his current work crafting alternatives to the State Water Board’s flow-based approach to maintaining and improving water quality in the Bay-Delta watershed in what is known as the Healthy Rivers and Landscapes program. He helps clients challenge administrative agency decisions through agency appeals and litigates agency decisions in court. His current work includes litigation contesting bond resolutions for the Delta Conveyance Project (DCP), challenging State Water Project (SWP) contract determinations by the California Department of Water Resources (DWR) and disputing the constitutionality of the State Water Board’s water quality certification fee.

Outside of his law practice, Aaron enjoys spending time with his family, hiking, and skiing.

Representative Matters

Water Resources

Serve as special counsel to the Sites Project Authority (Authority) in its pursuit of a water right permit from the State Water Board for the Sites Reservoir Project, a proposed new reservoir in the Sacramento Valley with a storage capacity of 1.5 million acre-feet. Represented Authority in quasi-judicial administrative hearing before the State Water Board Administrative Hearings Office (AHO) assisting in the preparation of expert testimony, presentation and defense of expert witnesses, and cross-examination of protestant witnesses.

Serve as special counsel to the County of Sacramento, Sacramento County Water Agency (SCWA), City of San Diego, City of Yuba City, and Carmichael Water District on water rights and resources matters.

On behalf of municipal and irrigation district clients, negotiated Central Valley Project repayment contracts pursuant to the Water Infrastructure Improvements for the Nation Act. Successfully defended these clients in district court litigation challenging these contracts. Currently representing these clients in appeal to the Ninth Circuit Court of Appeals.

Advised San Luis Obispo County Flood Control and Water Conservation District on water rights matters related to petitions for changes to the appropriative rights supporting its Nacimiento River water supply and secured approval of these petitions by the State Water Board to facilitate implementation of a water sales program.

Counsel clients regarding transfers of appropriative, contract, and remediated water rights and supplies, including preparation of purchase and sale agreements and related regulatory matters.

Litigation/Administrative Proceedings

Manage litigation filed by Napa County Flood Control & Water Conservation District, Solano County Water Agency, and the City of Yuba City in Sacramento Superior Court against DWR challenging DWR’s interpretation of the water accounting and carryover storage provisions in their SWP contracts.

Secured a favorable judgment for the County of Sacramento, SCWA, and the City of Yuba City as defendants in state court litigation wherein DWR sought to validate its authority to adopt bond resolutions and issue bonds for the DCP. Successfully defended this judgment on appeal before the Third District Court of Appeal. Represent the same clients in new litigation filed by DWR attempting to validate new DCP bond resolutions.

Manage the City of San Diego and San Diego County Water Authority’s Proposition 26 litigation in Sacramento Superior Court challenging the constitutionality of the State Water Board’s water quality certification fee.

Managed County of Sacramento and SCWA’s protests of the California WaterFix Project’s petitions for changes before the State Water Board, including preparation, presentation, and defense of expert witnesses and cross-examination of DWR’s witnesses. Assisted in the preparation of SCWA witness testimony and defense of witnesses before the AHO in the DCP water right change petition hearing.

Managed SCWA’s petitions for changes through a quasi-adjudicative hearing before the AHO, including preparation, presentation, and defense of expert witnesses and cross-examination of opposing party witness. Secured a favorable order from the AHO/State Water Board approving changes to SCWA’s water rights, thereby providing almost 1,000 acre-feet of new water for municipal uses throughout a portion of Sacramento County.

Local Government

Serve as general counsel to Carmichael Water District and Glenn-Colusa Irrigation District.

Sustainable Groundwater Management Act

Advised municipal and irrigation district clients and negotiated agreements forming Groundwater Sustainability Agencies (GSAs) pursuant to the SGMA.

Advise GSAs in the preparation and implementation of GSPs.

Successfully developed and implemented strategies for the adoption of Proposition 218 compliant water rates for irrigation districts and a joint powers authority fee for SGMA planning costs.

Land Use

Counsel clients in the preparation of Water Code section 10910 Water Supply Assessments and Urban Water Management Plans.

Insights and Activities

  • Co-wrote article titled, “Testing NEPA’s Flexibility for Forest Management Projects in California,” for the Spring/Summer 2022 edition of the Environmental Law News, published by the California Lawyers Association. The article assesses the capacity for the National Environmental Policy Act to accommodate critical forest management projects. [Read the article here [PDF]]
  • Co-Presenter, “SGMA Isn’t Working – When It’s Time to Adjudicate. Wait, When Is it Time?” Third Annual Western Groundwater Congress, Groundwater Resources Association of California, Virtual Event, Sept. 2020 [Read full transcript]
  • Panelist, “Sustainable Groundwater Pumping: Long-term Agricultural Sustainability,” American Ground Water Trust Annual Colorado Groundwater Conference, Denver, Nov. 2019
  • Panelist, “Western Water Infrastructure,” (Delta Tunnels and WaterFix Update) CLE International 23rd Annual Western Water Law Conference, Las Vegas, NV, Feb. 2018
  • Member, Groundwater Resources Association of California
  • Affiliate, Association of California Water Agencies (ACWA)
  • Affiliate, Northern California Water Association (NCWA)

Recent Articles

Ninth Circuit Confirms Reclamation Could Convert Water Service Contracts to Repayment Contracts Without Environmental Review

On August 17, 2026, the Ninth Circuit Court of Appeals affirmed the District Court ruling that the United States Bureau of Reclamation (Reclamation) did not need to undertake National Environmental ... Read More

Court of Appeal Affirms Trial Court’s Rejection of Financing Scheme for Delta Conveyance Project

On December 31, 2025, the Third District Court of Appeal issued an opinion rejecting the Department of Water Resources’ (DWR) attempt to validate its authority to issue revenue bonds for ... Read More

Ferguson and Chester Write for ENVIRONMENTAL LAW NEWS - Testing NEPA’s Flexibility for Forest Management Projects in California

In an article for the Spring/Summer 2022 edition of the Environmental Law News, published by the California Lawyers Association, Aaron Ferguson and Michelle Chester assess the capacity for the National ... Read More

Governor Newsom’s Latest Executive Order Takes Local Approach to Drought Response

Last week, Governor Newsom issued an executive order calling on state and local agencies to increase water conservation measures following the driest January, February, and March on record. Executive Order ... Read More

Water Users Legally Obligated to Rein in Certain Outdoor Water Uses

Despite the exceptionally heavy rain events in October and December 2021, California is still experiencing severe drought conditions. In response to these statewide dry conditions, and Governor Newsom’s October 2021 ... Read More

Education

  • University of the Pacific, McGeorge School of Law (J.D., 2010)
  • California State University, Sacramento (M.P.P.A., 2001)
  • University of California, Santa Barbara (B.A., 1995)

Selected Admissions

  • California
  • Washington

Spotlight

Read the full transcript from Aaron’s September 2020 virtual presentation for GRA’s Third Annual Western Groundwater Congress. “SGMA is complicated, groundwater adjudications can be complicated, but we’ve identified four key issues to focus on when determining whether the SGMA process has run its course and it is time to adjudicate.”