

Sarah Klahn has over 20 years’ experience trying complex water cases, including matters in state district and water court, federal court, and before administrative agencies. To her trial practice, she brings a technical background in science and mathematics which facilitates her work with technical and engineering experts. Her clients value her willingness to take cases to trial when necessary, as well as her ability to negotiate durable solutions to complex matters when possible.
Sarah’s clients include municipalities, ground water districts, ranchers, and private entities in Colorado, New Mexico, Idaho, and Wyoming, for whom she has tried cases of first impression, settled large complex matters, and won appeals in both the Idaho and Colorado Supreme Courts. In addition to her expertise in water law, she has also litigated cases involving the extent of agency authority, state and federal jurisdictional questions, water quality, municipal law, and Taxpayer Bill of Rights (TABOR) issues. Sarah represents Texas in the dispute over the Rio Grande Compact, Texas v. New Mexico and Colorado (Original No. 141), pending before the United States Supreme Court.
In addition to her work on behalf of clients, she has acted as an expert witness on water law process and procedure, including serving as an expert witness in the Colorado redistricting case Hall v. Moreno. Moving to the other side of the courtroom, Sarah serves as the hearing officer for the Truckee River Operating Agreement, which provides a prospective means to resolve disputes under this complex agreement dividing up the waters of Truckee River basin between the two states of California and Nevada as well as numerous federal and local interests.
Sarah also makes time to give back to her profession in various writing and speaking engagements; annually she is the editor of the Water Law Chapter of Colorado Methods of Practice, the editor of the FNREL Mining Law chapter on water rights, and she edits the Water Rights-Water Quality chapter in the Colorado Bar Association’s Water Law Benchbook. She is a co-author of Law of Water Resource Utilization published by the ABA in 2019.
In her off hours, you’ll find Sarah in the mountains—running, hiking, or back-country skiing. She also enjoys open water swimming in various beautiful mountain lakes, including Lake Tahoe, which she swam across in 2018.
Sarah has represented the City of Pocatello, Idaho, in a series of matters of first impression involving the development of conjunctive management of ground and surface water rights.
Sarah also represented the City of Pocatello, Idaho, to prosecute a water right claim in the Snake River Basin Adjudication seeking water rights for the City under a federal law theory based on the 1888 Pocatello Township Act. This case was appealed to the United States Supreme Court, which denied certiorari.
In 2005, Sarah brought suit against the Colorado State Engineer for failure to protect vested water rights of ranching interests from the impacts of groundwater diversions associated with oil and gas development. The Colorado Supreme Court affirmed the water court, finding that the State Engineer had an obligation to regulate oil and gas groundwater diversions.
Colorado’s State Engineer determined to regulate oil and gas groundwater diversions by regulation, but gave a pass to regulation of tribal oil and gas development despite the fact that the Southern Ute Indian Tribe had adjudicated rights under the McCarran Amendment as well as state water rights. The Supreme Court reversed, determining that Tribal oil and gas development leading to groundwater diversions was susceptible to regulation.
Sarah has extensive experience in Colorado Water Court, including cases involving diligence, augmentation change of water rights, and the intersection between water quality and water quantity.
Sarah represented the Yellow Jacket Conservancy District in diligence cases in which the primary issue was whether the District, sitting with “holdover” board members, was authorized to seek diligence in the first place. The Supreme Court agreed that it was, and that the “holdovers” retained authority to act on behalf of the District so long as there was no showing of fraud.
Rangen, Inc. v. Idaho Dep’t of Water Res., 367 P.3d 193 (Idaho 2016) Widefield v. Witte, 340 P.3d 1118 (Colo. 2014) Yellow Jacket Water Conservancy Dist. v. Livingston, 318 P.3d 454 (Colo. 2013) Pawnee Well Users, Inc. v. Wolfe, 320 P.3d 320 (Colo. 2013) A & B Irrigation Dist. v. Spackman, 315 P.3d 828 (Idaho 2013) A & B Irrigation Dist. v. Idaho Dep’t of Water Res., 284 P.3d 225 (Idaho 2012) LoPresti v. Brandenburg, 267 P.3d 1211 (Colo. 2011) Well Augmentation Subdistrict of Cent. Colo. Water Conservancy Dist. v. City of Aurora, 221 P.3d 399 (Colo. 2009) William F. West Ranch, LLC v. Tyrrell, 206 P.3d 722 (Wyo. 2009) Vance v. Wolfe, 205 P.3d 1165 (Colo. 2009) Pocatello v. State, 180 P.3d 1048 (Idaho 2008), cert. denied, 129 S. Ct. 754 (2008) Gallegos v. Colo. Ground Water Comm’n, 147 P.3d 20 (Colo. 2006) City of Thornton v. City & County of Denver, 44 P.3d 1019 (Colo. 2002) Eagle Peak Farms, Ltd. v. Lost Creek Ground Water Mgmt. Dist., 7 P.3d 1006 (Colo. App. 1999)