Lake Type: Freshwater Resevoir
Surface Area: 708 acres 
Shoreline Length: 4.4 miles
Elevation: 2073 feet
Average Depth: 23 feet
Maximum Depth: 30 feet
Water Residence Time: 3 years
Trophic State: Mesotrophic
Water to Aquifer: 4 mgd
Liberty Lake is located near the Spokane River in the northeast portion of Washington State. The lake was made through glacial activity and is surrounded by hills on three sides. Land use in this area is mainly residential development, and is experiencing rapid growth. The watershed, located over the Spokane-Rathdrum Prairie Sole-Source aquifer, is made up of shallow, permeable soils that rapidly drain over bedrock to the lake.
In the mid 1960s Liberty Lake began to show symptoms of eutrophication. Eutrophication is the process in lakes when plant life, especially algae, begins to rapidly increase due to the abundance of mineral and organic nutrients. Numerous sources were identified as contributors to nutrient enrichment of the lake, including a marshy area adjacent to the lake; unsewered homes near the lake; leaking sewer pipes; and stormwater.
Since 1973, the Liberty Lake Sewer and Water District has taken many measures to protect the lake and maintain the aesthetic beauty which has brought many residents to the area. As part of these efforts, water quality monitoring efforts dating back as far as 1968 have been conducted by Washington State University. These efforts include involvement in a restoration project, numerous thesis studies, an Alum treatment, a dredging of the lake bottom to remove nutrient rich sediment, and annual lake and watershed monitoring.
Organizations Protecting Liberty Lake
Liberty Lake Sewer & Water District No 1
Washington Department of Ecology – TMDL Phosphorus
City of Liberty Lake, WA
Spokane County Liberty Lake Regional Park
Studies, Reports, Articles and Presentations
Liberty Lake Total Phosphorus Total Maximum Daily Load Ecology
2010 Liberty Lake Solving Pollution Problems – Ecology
2008 Liberty Lake Data Set Evaluation
1993 Liberty Lake TMDL Phosphorus – Ecology
1979 Liberty Lake Effect of Restoration Project – EPA
1976 Liberty Lake Algae Bloom
