A Strategy to Minimize Sediment Delivery to a Wetland Restoration at Juanita Beach Park in Kirkland, Washington

This paper discusses the design of a marsh restoration at Juanita Beach Park in Kirkland, Washington. The marsh attempts to recreate lakeside habitat and hydrologic function that has become relatively rare in contemporary times. The marsh design presented many challenges, primarily associated with the depositional environment near the mouth of Juanita Creek and a reversed hydrologic regime on Lake Washington. The project team developed a diversion weir design featuring a slot with stop logs. With the stop logs in place, the weir slot excludes higher wintertime flows and accompanying sediment from the marsh; with the stop logs removed during the spring and summer, the weir slot will facilitate fish passage and feed lower flows into the marsh. The low-profile overflow weir maintains floodplain hydraulic function during extreme events. The design team also developed an operation plan that attempts to minimize potential sediment delivery to the marsh, while maximizing the opportunity for fish passage.