Projects & Programs
Suncadia Resort/Cle Elum Urban Growth Area Environmental Impact Statement Project, Washington
The impact on streams and aquifers of developing a water supply system within the surrounding watershed was a critical issue in the environmental review of the proposed Suncadia Master Planned Resort (MPR). The 7,500 acre resort overlaps the urban growth area of the City of Cle Elum in the upper Yakima River Basin of central Washington. Potential impacts include reduction of irrigation storage and third-party impacts resulting from water right transfers. The basin contains five U.S. Bureau of Reclamation (Reclamation) projects, five major irrigation districts, three counties, and over a thousand individual water rights. PNNL staff determined the amount of water available within this over-allocated basin for consumption by the MPR, evaluated water resource impacts on third-parties and developed a mitigation plan.
PNNL staff worked closely with the resort’s water rights attorney during development of the water supply plan. For each water right purchase and subsequent change application to the State, PNNL staff estimated the former net consumptive use of the irrigation water rights and the amount of water available to these crop demands. PNNL staff also evaluated the change in streamflow and reservoir storage that would result from a proposed transfer contract between the resort and Reclamation. PNNL staff developed a water balance model to determine cumulative effects on tributary and mainstem streamflows in the upper basin due to the proposed changes to the place, purpose, period of use and point of diversion of 28 water rights.
The Washington State Department of Ecology was concerned about ground-surface water interactions and increasing water demands due to induced growth. PNNL staff integrated groundwater models into the water balance model. The model showed that groundwater return flow of drainage from the resort golf courses would offset the effect of eliminating tributary irrigation return flows to the mainstem. The availability of water to meet the net consumptive water use of future, induced growth was assessed for mitigation and water banking purposes. PNNL prepared a streamflow monitoring plan to determine diversion allowances for the resort during drought and long-term average conditions. PNNL designed real-time streamflow monitoring stations on two tributaries, which will transmit data via a geostationary operational eEnvironmental satellite.
Project Highlights:
- Water availability was determined for 28 water rights
- Water balance model was developed to assess cumulative impacts
- A ground-surface water model was integrated into water supply and drainage plans
- Developed monitoring a water bank plan and streamflow gauge station designs
- Proposed to mitigate for induced growth
- strategic watershed planning via the environmental impact statement process