Winchester Lake is located within the exterior boundaries of the Nez Perce Reservation, about 30 miles southeast of Lewiston, Idaho. Originally, the lake served as a mill pond from 1910 to 1963. The 100-acre body of water is now the central focus of a 218-acre State Park that surrounds the lake.
In the late 1980s, local residents and visitors increasingly complained about the lake's nuisance algae blooms and poor water clarity. In 1990, through EPA's Clean Lakes Program, high levels of nutrients and low levels of dissolved oxygen were identified as adversely affecting water quality in the lake. In 1996 Idaho's 303(d) list of impaired waters identified Winchester Lake as not meeting state water quality standards, requiring the development of a Total Maximum Daily Load (TMDL).
A local Watershed Advisory Group (WAG) was formed in 1998 to develop recommendations for improvements that they wanted to see installed in the area. The WAG members are local residents from all sectors, including stakeholders from the agriculture and grazing communities, forestry, the Nez Perce Tribe, the Road District, city government, and recreation. A Memorandum of Understanding (MOU) was developed between the state of Idaho, Nez Perce Tribe, and EPA with the intent to work collectively on the development of the TMDL. In February 1999 the TMDL was completed and approved, representing the success of the collaborative approach of the many agencies and the WAG.
Following the completion of the TMDL, the Nez Perce Tribe received 319 funding to help implement water quality projects in the watershed, as an integral piece of the TMDL's phased implementation plan. Funds were used to restore two forest road segments noted as high sediment producers in the TMDL. Gates for seasonal closure were also installed to restrict travel during the wet season.
Using 319 funds, the tribe collaborated with private landowners along the stream corridor to enhance riparian shading and stabilize streambanks. In spring 2000, volunteers and personnel from Nez Perce Tribe Water Resources, the Natural Resources Conservation Service, and the Soil Conservation Commission planted 150 trees and shrubs. A larger planting effort for 2,500 shrubs was planned for the remainder of the corridor.
These ongoing improvements are possible because of the collaborative efforts among the many Nez Perce tribal departments, state and federal agencies, private landowners, and members of the watershed group. Restoration efforts in this watershed will continue with additional 319 funding for agricultural practices, livestock best management practices, riparian plantings, culvert replacements for fish passage and maintenance, and road rehabilitation.