SEPA RULES
DESCRIPTION OF PROPOSAL: Wanapum Dam Upper Boat Launch Repair Project
RCW 197-11-970
DETERMINATION OF NONSIGNIFICANCE
DESCRIPTION OF PROPOSAL: Wanapum Dam Upper Boat Launch Repair Project
Proposed Improvements:
The proposed Project is to install wave and sediment barriers on the north and south sides of the existing Wanapum Dam Upper Boat Launch to protect the ramp from debris buildup and to protect the floats from wind and wave damage.
The proposed project includes the following items:
l Install and construct erosion control features and turbidity curtain
l Construct earthen dredge platform and upland stockpile erosion control features
l Dredge up to 500 cubic yards of accumulated sediment
l Boat launch float
o Remove two currently remaining boat launch floats
o Reinstall five launch floats post-construction
o Permanently remove outermost float and associated support pile (192 square feet)
l Wave and sediment barrier
o Install 69 z-sheetpile segments, with gap for fish movement, for northern wave barrier
o Install 37 z-sheetpile segments for southern sediment barrier
o Install six temporary 12-inch hollow steel piles or 12-inch steel H piles for sheetpile alignment and positioning
o Install five permanent 12-inch hollow steel piles to support barriers
o Install 60 cubic yards of quarry spalls for erosion protection at the float rest concrete planks and concrete ramp
The effect of the disturbance to fish use of the shallow water habitat areas associated with this boat launch repair project will be minimized and mitigated through the removal of an overwater structure at the Columbia Cliffs site, which is in the same Water Resource Inventory Area. This project was completed in October 2014, under a separate permitting process, to enable Grant PUD to complete the pier removal project in the dry, during the emergency drawdown of Wanapum Reservoir. The compensatory mitigation action at the Columbia Cliffs site will result in an immediate and long-term improvement to habitat conditions and functions within the Wanapum Reservoir through the removal of overwater shading to support juvenile rearing and migratory movement; removal of invasive vegetation and subsequent planting of native species to support prey resources, nutrient cycling, and natural habitat complexity along the riparian zone; and removal of creosote source material to improve water quality conditions.
PROPONENT: Public Utility District No. 2 of Grant County
LOCATION OF PROPOSAL, INCLUDING STREET ADDRESS, IF ANY:
The proposed boat launch repair project is located on the left bank (east side) of the Columbia River, immediately upstream from Wanapum Dam (river mile 416) just west of SR 243, Grant County, Washington (Section 16, Township 16 North, Range 23 East, WRIA 41).
The compensatory mitigation project at Columbia Cliffs is located within the same watershed as the boat launch repair project, on the left bank (east side) of the Columbia River at river mile 442.5 near Crescent Bar Resort in Douglas County, Washington (Section 14, Township 20 North, Range 22 East, WRIA 41).
LEAD AGENCY: Public Utility District No. 2 of Grant County
The lead agency for this proposal has determined that it does not have a probable significant adverse impact on the environment. 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.
o There is no comment period for this DNS.
o This DNS is issued after using the optional DNS process in WAC 197-11-355. There is no further comment period on the DNS.
6 This DNS is issued under WAC 197-11-340(2); the lead agency will not act on this proposal for 14 days from the date below. Comments must be submitted by February 10, 2015 5:00 PM Pacific Standard Time.
Responsible official: Ross Hendrick
Position/title: License Compliance and Implementation Services Manager
Phone: 509-793-1468
Address: P.O. Box 878
30 C St. SW
Ephrata, WA 98823
Date: 1/26/15 Signature: /s/Ross Hendrick _______________
6 There is no agency appeal.
#02009/4245032
Pub.: January 28 & February 3, 2015