Water Conservation & Supply
Water supply management has become more difficult in recent decades due to increases in demand, changes in volume and timing of available runoff, and a greater understanding of the need to leave water instream for aquatic habitat. WPN has conducted numerous Basin Studies and Conservation Plans that evaluate an entire water supply system to ensure reliable, cost-effective, and sustainable water supply and management. Key parts of this work are:
- Evaluating existing and future water supply - Surface water, groundwater, and snowpack (and in some cases glacial melt) provide the water that is available to meet demand. Evaluating the sustainability of these sources, or the potential for further development of them, typically involves field investigations, analysis of historical data, and climate, hydrologic, groundwater, and water resource modeling.
- Water Rights and Water Use - An analysis of any water system must include compiling all potable, irrigation, hydropower, storage, and instream water rights and actual water use. Although much of this data is typically available from government agencies, water use data often needs to undergo a quality review as well as make sure the seasonal variability is represented.
- Instream flow assessments - Recent decades have seen an increased understanding of the need to leave more water instream for aquatic habitat. WPN has been involved with fisheries habitat analysis and instream flow assessments (IFIM)
- Water Conservation Plans - Most potable and irrigation districts have the potential to increase the efficiency of their delivery systems, and therefore can meet a greater demand more reliably with less water. Increases in efficiency can be achieved through piping open canals (reducing seepage and overflows), eliminating pipe leaks or operation overflows (using telemetry or other to have diversions more closely match usage), or reducing on-site usage (e.g., low-flow fixtures in homes or micro irrigation systems on farms). Although Water Conservation Plans should evaluate the whole system, an emphasis is typically placed on the summertime when natural streamflow is the lowest and withdrawals from rivers are the highest. The plans may also want to evaluate potential funding sources for implementation.
- Surface Water Storage / Reservoir Planning - Many basins seeing water shortages or low summer streamflows can benefit from new or expanded reservoir sites. Evaluating the potential for this typically involves the determining the following; target volume based on timing of inflow and water use, geology and topography for feasibility and stage/storage relationships, reservoir operating rule curves, planning-level design and cost estimates, and evaluating fisheries and other downstream impacts. Any evaluation of reservoir sites should be accompanied by a water conservation assessment to determine if comparable reliability may be met through alternative means.