Sheryl A. Sweeney

Legal Assistant: Lisa Gefroh


Sheryl joined Ryley Carlock & Applewhite in 1984. She practices in the areas of energy law, water law (both Arizona specific and the “Law of the River” with respect to the Colorado River), environmental law, electric-utility law, public power, and special taxing districts. Sheryl currently serves as Practice Group Leader for the firm’s Water, Energy, Resources and Environmental Law Practice.

Sheryl has extensive experience representing both public and private energy interests. She acts as counsel to several entities that contract for hydroelectric power from the Western Area Power Administration and the Arizona Power Authority.  She is involved in all aspects of the industry, including power supply contracting, rate setting, transmission access, including interconnection agreements, renewable generation, conventional generation, distributed generation, siting and retail electric competition.

She has extensive experience in all aspects of Arizona water issues and represents numerous land developers, successfully securing 100-year assured water supply certificates for several major developers in the state of Arizona.

Sheryl also has represented many golf course owners and assisted in securing the necessary water rights for a variety of golf courses and lakes. She also has represented golf course owners dealing with compliance and enforcement matters.

Her practice includes all aspects of documenting, acquiring, transferring and perfecting groundwater and surface water rights in Arizona. She also has prepared hundreds of water rights claims in the two Arizona general stream adjudications.

Sheryl serves as counsel to several irrigation and electrical districts, addressing all aspects of special taxing district issues. Her practice in this area includes everything from open meeting law compliance to election law compliance to advice regarding the investment of public funds.

Sheryl's practice also includes environmental real estate due diligence and environmental permitting and compliance. Her experience ranges from underground storage tank cleanups, asbestos removal contracting and "community right to know" compliance to effluent reuse permitting. She has undertaken the environmental due diligence review for hundreds of properties in Arizona and elsewhere.

Sheryl has participated in a number of matters involving the National Environmental Policy Act (NEPA) and the Endangered Species Act. She also has participated in drafting and structuring many regulatory rulemakings, both at the state level and federal level, and has been actively involved in drafting legislation in all areas of her practice.

She is a native of Kansas and received her bachelor's degree in sociology from Kansas State University in 1980. She received her law degree from the University of Kansas in 1984.


Sheryl has written and spoken on topics including retail electric competition, effluent reuse, developments in environmental law, and underground storage tank compliance. Her recent publications and speaking engagements include:

Speaking Engagements

  • "How to Turn Colorado and Arizona Water Rights Into a Valuable Asset," Ryley Carlock & Applewhite Seminar, May 2016
  • "Without a Paddle: Navigating the Murky Waters of the Clean Water Act's Definition of 'Waters of the U.S.'," U.S. Society for Irrigation and Drainage Professionals' Water Management Conference, Co-Presenter, December 2014
  • "Water and Energy," Law Seminars International, April 2011
  • "Arizona Water Laws and Regulations," Halfmoon Seminars, February 2009
  • "Future Leadership Opportunities for Women in the Water Industry," Arizona Women in Water Network, May 2007
  • "Water Rights Sales and Transfers as a Water Management Tool in Arizona," Lorman Education Services, May 2007
  • "Recent Amendments to ADWR's Assured and Adequate Water Supply Rules for New Subdivisions," MCBA Environmental Law Section, October 2006
  • "Effluent Reuse 2000," Arizona Water & Pollution Control Association, July 2000
  • "Electric Retail Competition," MCBA Corporate Counsel Division Seminar, November 1997
  • "Environmental Consulting Contracts," MCBA Ethics and Contracting Concerns of Environmental, Legal and Consulting Practices Seminar, May 1997
  • "Development in Soil Clean-up Standards," Ryley Carlock & Applewhite's Recent Changes in Arizona's UST Program Seminar, May 1996
  • "Essential Issues in Natural Resources and Environmental Law for Lawyers and Lay People," Flagstaff Chamber of Commerce and Northern Arizona University Seminar, May 1993


  • American Bar Association
  • Maricopa County Bar Association, Environmental and Natural Resource Law Section
  • State Bar of Arizona, Environmental and Natural Resource Law Section
  • Colorado River Water Users Association, Member
  • Valley Forward, Member
  • Arizona Farm Bureau, Member
  • Arizona Town Hall, Member
  • Arizona Women Lawyers Association, Member
  • American Society for Testing Materials, Member
  • Audubon Arizona, Director, 2010-present


Sheryl is an AV-Rated attorney by Martindale-Hubbell. She has been ranked by Chambers USA since 2011 in Environmental Law. In 2014, she was ranked a Band 1 attorney, the highest ranking awarded by Chambers. She has also been listed in Best Lawyers in America® and in Super Lawyers, both since 2007. Best Lawyers named Sheryl “Lawyer of the Year” in the 2022 and 2019 editions in the area of Natural Resources Law. Sheryl was named one of 2017’s Most Influential Women and 2018’s Top 100 Lawyers in Arizona by AZBusiness Magazine. In September 2021, the Agribusiness & Water Council of Arizona presented Sheryl with a Lifetime Achievement Award to recognize her deep knowledge of Arizona water law and her decades of experience providing advice to irrigation and drainage districts across the state.

Ranking Arizona