US Army Corps of Engineers
Walla Walla District

Sweetwater & Lapwai Creeks Aquatic Ecosystem Restoration Study

The U.S. Army Corps of Engineers, Walla Walla District (Corps), seeks public comments regarding the scope of the Sweetwater and Lapwai Creeks Aquatic Ecosystem Restoration Study. The Corps, in partnership with the non-federal sponsor, the Nez Perce Tribe, is developing a plan to restore aquatic and riparian habitats on Sweetwater and Lapwai creeks and prepare a Feasibility Report/Environmental Assessment (FR/EA). 

Scoping comments will be accepted from April 5, 2019, through May 4, 2019. The Corps is particularly interested in input regarding alternatives and environmental effects that should be considered. Scoping comments will be used in: 1) identifying issues to address; 2) exploring alternatives; and 3) identifying potential environmental effects of possible changes to the watershed. 

Electronic comments may be emailed to NEPANWW@usace.army.mil, inserting “Sweetwater 203” in the subject line. You may also mail comments to: 

U.S. Army Corps of Engineers
Walla Walla District, ATTN: PPL-C Sweetwater 203
201 North 3rd Avenue
Walla Walla, WA  99362-1876

Background – Sweetwater Creek is a tributary to Lapwai Creek, which flows into the Clearwater River, located predominantly on the Nez Perce Reservation and near the cities of Lapwai and Lewiston, Idaho.

The Sweetwater and Lapwai creeks' watersheds contain important spawning and rearing habitat for ESA-listed Snake River steelhead and re-introduced coho salmon. 

In addition to supporting important fisheries populations, the watershed and its streams have cultural significance to the Nez Perce Tribe. 

Vulnerabilities – Conditions in the watershed have been negatively impacted by development and land management. Numerous opportunities exist to restore the ecosystem including restoration of floodplain habitat and connectivity, improving in-stream habitat quality, channel capacity, protection of cool spring refugia, improvement of fish passage, and restoration of environmental flows.

The Study – The Sweetwater and Lapwai Creeks Aquatic Ecosystem Restoration Study will evaluate the current conditions of Sweetwater and lower-Lapwai creeks in terms of water quality, aquatic habitat and stream channel condition. Based on this assessment, the study will determine potential restoration actions to improve in-stream habitat conditions. The focus of the study will be on developing ecosystem improvements to benefit ESA-listed Snake River steelhead and other native species, and protect natural and cultural resources of significance to the Nez Perce Tribe. Habitat improvements for ESA-listed fish at all life stages will contribute to stronger returns, benefiting the entire Columbia River basin. The project would enhance sustainability, restore floodplain form, function and processes, and benefit fish populations in the Pacific Northwest.

The Corps is committed to working with our non-federal sponsor, the Nez Perce Tribe, and the larger community to restore significant ecosystem function, structure and dynamic processes that have become degraded in Sweetwater and Lapwai creeks. Alternatives considered might include channel naturalization, riparian plantings and restoration, creating gravel beds, placing large woody debris, and improving off-channel habitat.

The Sweetwater Creek study will also include coordination and consultation with other federal and state agencies to integrate and leverage agency knowledge of the Sweetwater and Lapwai Creek ecosystems.

The study process will include outreach activities with citizens and stakeholders across the community to gather their thoughts and ideas related to the way we could restore ecological and cultural values and other important water-resources considerations.

Contact Us

201 N. 3rd Ave.
Walla Walla, WA 99362
509-527-7239
NEPANWW@usace.army.mil