McDonald Creek is an independent drainage to salt water, entering the Strait of Juan de Fuca west of Dungeness Bay. The drainage is 13.6 miles long, draining approximately 23 square miles of the northwest flank of Blue Mountain. The headwaters originate at approximately 4,700 feet; it flows through a deeply incised coastal upland, and across a marine bluff to saltwater. The creek, similar to other streams with their headwaters in the foothills, is subject to hydrologic and stormwater effects as a result of permanent forest cover loss, (forestry and conversion to residential development). These impacts increase stream power, erosion, and sediment transport lower in the system. Primary land uses are commercial timber and private woodlots. An administrative closure for new water rights is in place.
McDonald historically supported coho and chum salmon, steelhead, cutthroat and rainbow trout. Currently coho salmon, winter steelhead and cutthroat are found. Excessive sediment impacts salmon when they are feeding, spawning and trying to see predators in order to keep away from them. Instability in the channel means habitat conditions are generally less than good for salmon survival and reproduction. Elevated dissolved oxygen is harmful to aquatic ecosystems and directly impacts fish. Irrigation water from the Dungeness River entering the creek can impact the migration patterns of both the McDonald Creek fish, as well as attract Dungeness River fish to McDonald Creek.
- State of the Waters of Clallam County 2004