Stormwater Separation Environmental Assessment

In collaboration with the City of Port Angeles, the Olympic National Park is inviting the public to review and comment on the Port Angeles Stormwater Separation Project, a component project of Elwha Restoration.

The proposed project is part of mitigation proposed by the National Park Service (NPS) to protect the Lower Elwha Klallam Tribe community from impacts of removing the two dams on the Elwha River. After the dams are removed, additional sediment will be carried downstream by the river, leading to higher stream flows and higher groundwater in the river's flood plains, which include areas within the Lower Elwha Klallam reservation. In turn, higher groundwater will increase the risk of septic system failures on the reservation.

To protect the tribal community from this increased risk and provide for continued collection and treatment of the community's wastewater, the NPS is constructing a wastewater collection system for the reservation. In collaboration with the City of Port Angeles, the collected wastewater will then be treated and discharged to the City's existing wastewater treatment plant.

The preferred alternative proposes to collect stormwater from impervious surfaces in a four-block area of downtown Port Angeles and keep it separate from household wastewater and sewage. The proposed project involves construction of a new storm drain which would collect stormwater from this area, and add it to an existing storm drain system along Valley Street which discharges Valley Creek into Port Angeles Harbor. All construction would occur within existing City streets.

Document Content:

Stormwater Separation Environmental Assessment   (8.1 MB, PDF file) Disclaimer: Links within the above document(s) were valid as of the date published. Note: Some of the files may be in PDF format and can be viewed using the Adobe Acrobat Reader software. You may download a free copy of from Adobe Systems.