SEPA MITIGATED DETERMINATION OF NONSIGNIFIGANCE (MDNS)
WAC 197-11-350
DESCRIPTION OF PROPOSAL: The Moses Lake Irrigation and Rehabilitation District (MLIRD) proposes to reconstruct the Moses Lake North Dam facility located 1.44 miles south of 1-90 along Sand Dunes Road, in Grant County, WA. The project will include dam removal and reconstruction, bridge construction over the dam and site improvements.
The project will reconstruct the existing dam which consists of earthen fill, concrete walls, metal culverts and metal manual gates with a new dam consisting of driven sheet piles, a cast-in place headwall, sidewalls and concrete apron, a pre-cast bridge with cast-in-place abutments and metal articulated gates. Foundation support for the new dam will consist of deep foundations. The new dam will be constructed generally within the existing dam footprint (+10%) estimated at 9,200 square feet including the spillway apron. Project will include site improvements consisting of a new asphalt parking area located northeast of the dam. Power utilities on-site will be relocated and accessed for the new structure. The site is located within 200 feet of Moses Lake and work will occur within the Crab Creek waterway.
During construction, appropriate erosion control devices would be installed and maintained to prevent erosion and prevent stormwater from entering Moses Lake and Crab Creek.
LOCATION OF PROPOSAL: Moses Lake North Dam, 1.44 miles south of 1-90 on Sand Dunes Road, Grant County, WA
PROPONENT/LEAD AGENCY: Moses Lake Irrigation and Rehabilitation District
RESPONSIBLE OFFICIAL: Curt Carpenter
POSITION/TITLE: General Manager, Moses Lake Irrigation and Rehabilitation District
ADDRESS: P.O. Box 98 Moses Lake, WA 98837
DATE: December 19, 2013 SIGNATURE: ________________
The lead agency for this proposal has determined that it does not have a probable significant adverse impact on the environment subject to the stipulated mitigations under the State Environmental Policy Act Rules. The lead agency has determined that there are no probable significant adverse impacts that cannot be mitigated and has issued a Mitigated Determination on Non-significance. An environmental impact statement (EIS) is not required under RCW 43.21C.030(2)(c). This decision was made after review of a completed environmental checklist and other information on file with the lead agency. This information is available to the public on request.
MITIGATING CONDITIONS:
1. Prior to beginning the project the applicant shall obtain all necessary authorizations from all agencies with jursdiction.
2. The work area shall be isolated from Crab Creek and Moses Lake with a sheet pile, sediment boom or other equivalent method to prevent sediment laden water from negatively impacting these waters.
3. Construction stormwater BMPs and Temporary Erosion and Sediment Controls must be installed and left in place until final stabilization of the site.
4. Applicant shall apply for and obtain coverage under the Washington State Construction Stormwater General Permit.
This MDNS is issued under WAC 197-11-340(2); the lead agency will not act on this proposal for 14 days from the issue date. Comments must be submitted by January 2, 2014.
#12063/3496813
Pub.: December 19, 2013