Eccles Creek Culvert and Fish Passage

DOWL provided hydrology and hydraulics analyses and fish passage design for Eccles Creek and Whiskey Creek in Cordova. The objective of this project was to improve fish and aquatic organism passage while providing adequate flood flow capacity to meet the State of Alaska Department of Transportation and Public Facilities design criteria. The design called for removing the existing eight-foot perched culvert in Eccles Creek and replacing it with a 19-foot arch culvert with a simulated channel and banks. The plunge pool created downstream of the existing culvert was filled and reconstructed to a natural channel section. The single 24-inch culvert in Whiskey Creek was replaced with a 66-inch by 51-inch pipe arch, incorporating a natural channel. The replacement culverts provide favorable fish passage conditions for juvenile and adult salmon and provide flood flow conveyance for the 50-year design storm event.