Walker River Basin Research Walker River Basin Research ProjectsProjects

James Thomas, Desert Research Institution

Walker Lake Basin Diverse Walker Lake Basin Diverse InterestsInterests

• Farming—Mason Valley is the largest economic agricultural valley in Nevada

• Native American tribe in lower part of the basin

• Large recreational area—fishing, hunting, boating, hiking

• Life style--Small Town pastoral way of life

• Lake—native Lahontan Cutthroat Trout, common loon migration stop over

• Walker Lake is one of only three desert terminal lakes in North America with a fresh water fishery

• 1882-2008, lake level has dropped 145 feet, and volume has decreased from about 10 to <2 million acre-feet

• Salinity (TDS) has increased from about 2,500 to 16,000 mg/l, threatening the fresh water fishery

• 1939-93, average Walker River inflow to lake was about 76,000 afy (84,000 afy), total Walker River flow for Sierra Nevada was 327,000 afy

• About 75% of Walker River flow is consumed by agricultural and native vegetation before reaching the lake

• About an additional 50,000 afy of flow, above the average annual natural flow is needed to maintain the lake at 10,000 mg/l

• 10,000 mg/l TDS needed to maintain the LCT fishery

Walker Lake Basin InformationWalker Lake Basin Information

Walker Lake Information—cont.Walker Lake Information—cont.• Recent legal action by downstream users seeks more flow to the lake

• Agricultural community built on full appropriation of the surface water flows and now have supplemental groundwater rights, so no water rights for the lake

• Can a healthy and viable agricultural community be maintained and have enough water for the lake to maintain a fishery and a healthy ecosystem

• Upstream users are concerned about the loss of water and agriculture on their economies and way of life

• The lawsuit prompted a mediation effort as well as a Federal allocation of $95M for studies on the effects of potential water rights acquisitions on the ecosystem and economy of the basin, conveyance improvements, and acquisition of water rights

Walker River Basin Research Walker River Basin Research ProjectsProjects

• Nevada System of Higher Education Walker Basin Project– Desert Research Institute– University of Nevada, Reno

• U.S. Geological Survey Walker Projects

• U.S. Fish and Wildlife projects– Lahontan cutthroat trout (LCT)

WHAT IS BEING STUDIED by DRI and UNR (NSHE)--Handout

1. Decision Support Tool (Watershed Model) for Water Rights Acquisition 2. Project Historical Account 3. Alternative Agriculture and Vegetation Management 4. Plant, Soil and Water Interactions 5. Current Ecological Health of Walker River and Lake 6. Health of River Channel and Lake with Increased Flows 7. Water Conservation Practices for Agriculture Producers 8. Economic Impact and Strategies 9. GIS Database Development: Water Rights and Distribution, Demographics and Economics10. Wild Horse and Burro Marketing

SeedingSeeding

• Cool season grasses and most revegetation grasses were planted Nov-Dec 2007

SummarySummary

Science will be used to inform water rights purchases:

• Which potential purchases from willing sellers will deliver the most water to the lake?

• Can water rights be purchased for the lake and not adversely affect the Walker basin economy?

• What are the effects of water right purchases on the Walker Lake basin ecosystem?

• Are lower water use alternative crops viable economically and can they be grown in the Walker basin?

• Can native vegetation be re-established on fallowed farm land to prevent invasive weed and dust problems?

Summary--continuedSummary--continued

Walker Lake basin projects (DRI, UNR, and USGS studies) will provide a unique opportunity to obtain a wealth of information on understanding the hydrology of the basin from the Sierra Nevada to the lake, the health of the river and lake, agricultural alternatives, restoration of fallowed land, and the economics of the basin.

The following presentations by DRI, UNR, and USGS scientists will provide an update on some of the ongoing research in the basin.