Along the arterial 35th Ave NE there is a low point in the road between NE 105th and 115th Streets. In past times before the building of roads and houses, the area was a natural flood plain for The Confluence of Thornton Creek. The two branches, North and South converge at this point. In 1996-98 the Meadowbrook Pond was created by Seattle Public Utilities as a flood control measure for holding stormwaters and filtering the water so that sediments would not “plug up the creek” downstream.
Since the time of its creation Meadowbrook Pond has functioned successfully at filtering sediments out of the water, but periodic flooding has still occurred on nearby streets and up into houses. The year 2014 is the third in the cycle of improvements and enlargements to Meadowbrook Pond and to the creek outlets into the pond, to increase the capacity for water.
Dramatic changes are underway along 35th Ave NE at NE 107th in Meadowbrook, where the roadway is being replaced with a bridge-like structure so that the South Branch of Thornton Creek now flows underneath, eastward into Meadowbrook Pond.
The rebuilding and repairing of 35th Ave NE is being done by a private contractor under supervision of the project by Seattle Public Utilities. Because of the time needed for rebuilding and waiting for the concrete to dry, no date has yet been set for re-opening of 35th Ave NE.
On both sides of 35th Ave NE, the creekbed of the South Branch of Thornton Creek was widened and meanders created to help slow the flow of water and filter sediment. All of the creek banks within the project area including the new flood plain, are now covered with coconut fiber erosion control blankets. These woven mats provide cover to stabilize the stream banks, prevent erosion and help hold plants in place. Landscaping work is continuing and there is still a lot of work to be done to replant the area.
so do you think builders way back when built knowing the homes in the area may flood? Oh how important all these drainage problems be addressed before hand!
North Seattle has been rapidly built up with houses and roads in the past seventy years since World War Two. The Thornton Creek drainage system extends over eighteen miles with the two branches converging in Meadowbrook. I think that in the past builders of roads and houses thought that putting in culverts would be enough to handle the water. Flooding is not specifically a problem caused just in Meadowbrook but over the entire watershed. We are all hopeful that this current Confluence Project will be enough to handle the water from now on. Only time will tell.