op:coop

King County and other Counties in the Pacific Northwest, has spent a significant amount of money annually on watershed restoration and stream habitat improvement. Unfortunately, the streams in urban, densely developed areas remain a lower priority in hierarchy of the State watershed restoration plans. We plan to create a small wildlife refuge in the middle of the city, a diversified micro-environment attractive to residential fish and birds.

The aim of this project is to restore the portion of Willow creak approx. 300 ft from NE 89th St to NE 92 nd St along Ravenna Ave NE. We will increase the water flow by narrowing the channel in the middle part of the creek (see photo) using a variety of techniques. Increased water flow is expected to reduce sediment already in the channel while we will prevent excess new sediment going into the creek on and off our property. We will remove invasive plants such as ivy, bamboo and yellow iris from the slopes and water, and replant the slopes with native plants such as Salal, Oregon grape, and other species.

The approximately 300 foot long portion of Willow creek, a tributary of Thornton Creek runs in the middle of Ravenna Woods Condominium property at 2300 NE 89th St, between three buildings erected in 1982. Although the narrow space around the creek had been designated and maintained as protected buffer area, there was not enough attention paid to the stream channel and slopes. As a result, the slopes erosion during the rainy season and uncontrolled growth of the invasive plants are choking the flow of water.

A substantial part of Willow creek is under the shade of two huge willow trees that are limbed and pruned regularly to let filtered light in. Plants on the creek’s slopes include both native vegetation such as dogwood thickets, rhododendrons and sword ferns, and alien invasive plants and weeds such as bamboo thicket, yellow iris and ivy, chocking the water flow and propagating uncontrollably. Streamside plantings are thick and chest high at the upstream end toward NE 89th St to provide a people barrier, then continue to decline in height. Past the last building, grass lines the creek. This portion of the creek receives almost full day sun. Beneath and between the rhododendrons and other ornamentals, like day lilies, the ground is mostly bare. The open grassy bank section is flat and marshy. The slope height declines from three feet tall at the upstream end to less than a foot tall at the downstream end; stream width follows a similar pattern, except that with each passing year the stream becomes shallower and wider because of slope erosion and excessive sediment deposition, and flow velocity declines while the marshy part of the creak increases.

The abundant wildlife we witnessed around the creek: raccoons, squirrels, opossums, mallards and a number of bird species, such as Anna hummingbirds, American robin, American goldfinch and many others are still around, although observed less frequently. Mallards that used to winter in our creek and even hatched their eggs there, all but disappeared because the creek became too shallow for them to swim in. Only American crow and squirrels seem to thrive as before.

Habitat conservation will benefit the 50 people living in our complex but also the Maple Leaf and Wedgwood neighborhoods around us, as well as for attracting back the wild life, as did similar projects on creeks restoration done on a greater scale by the City of Seattle at the NE 100th St, and in the Meadowbrook neighborhood, both downstream from us. Fish already have returned to these streams.