Regional commission accepts Cold Springs water-balance analysis; model to be shared with agencies

The Truckee Meadows Regional Planning Commission on a unanimous voice vote accepted a presentation and report on the Cold Springs water-balance analysis, a regionally funded study that models how groundwater and surface water interact within the Cold Springs closed hydro basin. The presentation was led by Kim Rigdon of the Western Regional Water Commission and Dwayne Smith, utilities and capital projects director for Washoe County, and the commission voted to accept the report after a question-and-answer period with commissioners.

The analysis was developed by Washoe County with Stantec as the consultant and funded through the Western Regional Water Commission (WRWC). Dwayne Smith said staff compiled precipitation, well pumping and reclamation inflow data, calibrated a groundwater–surface-water model, and is now running scenarios to show how new development, storm events and changes in water use would affect groundwater levels, White’s Lake and wastewater flows. Smith said, “that facility is a 700,000 gallon per day permitted facility. We’re flowing at about 400,000 gallons a day currently.”

Commissioners pressed staff on several operational and planning points. Commissioner Rob Pierce asked whether Cold Springs connects to neighboring basins; Smith replied that the Cold Springs boundary shown in the model defines a closed basin where precipitation falling inside the boundary remains in the basin and leaves only by evaporation absent a regional import or export project. Commissioner Michael Flick asked where the line is for initiating wastewater expansion; Smith cited Nevada Administrative Code requirements and described the multi-step facility-planning process used in other Washoe County projects. He told commissioners, “NAC, specifically requires, municipal wastewater purveyors to initiate planning processes when we hit a certain threshold of of flow coming in to the treatment plant.”

Kim Rigdon described how the WRWC prioritizes and funds projects. She said WRWC funding comes from a surcharge on public water systems, stating, “our budget comes from a 1 and a half percent surcharge fee to the public water systems in the area.” The project team also confirmed Stantec’s project lead, Dr. Claire Archer, and said the resulting numerical model will be turned over to agencies for continued use. In response to a question about model access, Dwayne Smith said the model “would be turned over to the agencies so that we can utilize that model and yes, test it, stress it, different scenarios etcetera.”

Presenters emphasized that the study addresses both quantity and quality. Smith noted the analysis includes stormwater and runoff impacts, evapotranspiration differences among land covers, septic-system and reclaimed-water effects on groundwater and potential mitigation tools such as reuse of highly treated recycled water. He said lessons from this Cold Springs model will be applied to other closed basins such as Lehi Valley.

The commission’s acceptance is an informational action; staff said the Cold Springs findings will be included in the public infrastructure plan and used to update capital improvement program data in the coming months. The governing board for the WRWC and related agencies will receive a version of the presentation at the October 9 meeting, and Washoe County staff indicated they will continue facility planning and scenario analysis to inform the timing and design of any wastewater expansions.

Commissioners and presenters repeatedly framed the model as a planning tool rather than a change in legal water rights. Commissioner Lazarevsky asked whether the model would enable taking water rights; a Washoe County representative answered clearly that the model provides technical information but does not create or revoke water rights, which are governed by law and judicial processes.

The commission accepted the report by motion and voice vote. Staff and the consultant will continue to refine the model, run additional scenarios and integrate findings into the regional public infrastructure and capital planning materials that will be presented in later hearings.