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Tuesday, December 14, 2010

Impacts of the Big Storm on Shoreline Area


Cromwell Park is at the Headwaters of Thornton Creek.
The restored wetlands are retaining over 2 acre ft of stormwater,
that would otherwise have rushed into Ronald Bog downstream. 
This Week's Rainstorm Definitely Made 
an Impact of the Community for a few Days.

Ronald Bog was overtopping its normal
bank and was nearly up to the roadway at 175th and Meridian
photo credit-Janet Way
Close-up of Mallards enjoying the larger
Ronald Bog
Photo credit-Janet Way
Maybe it wasn't the worst storm ever, but the stormwater runoff was encroaching into people's consciousness more than last week's storm.
Shoreline is constructing a "flood containment" wall
just south of the Bog at Corliss Ave.
They do seem to have a muddy water problem though
on this side of the wall, and it's running
into this storm drain just below

Stormdrain does contain a water quality
"sock" or filter that is supposed to contain the
sediment, but I wonder if this one is
really doing the job?

Thornton Creek is the largest watershed in Shoreline and Seattle and is beset with many problems due to the impacts of stormwater.  It is a salmon stream, but one that has suffered many setbacks due to the impacts of unwise development over the last century. The stream provided habitat to 5 species of salmonids, and there were large numbers of these fish even until about 30 yrs ago. But as the cities and county permitted development and undetained stormwater runoff to detract from the water quality the fish need, it has been tough for the fish to survive. But they still want to come back and the cities are now trying to undo some of the damage of the last century.

Here, Littles Creek emerges from a culvert under 12th Ave NE and takes a sharp right turn heading for Paramount Park. 
Littles Creek was running very high on Sunday
Its volume of water is obviously overtaxing
this channel and culvert
Sunday, at Paramount Park, Littles Creek was overtopping
the crossing and making  temporary waterfall.
Every year these medium sized storms cause erosion
at this location and cause massive sedimentation in
the creek. The sediment is one of the most
destructive factors for salmon morbidity.
The salmon eggs ("reds")get smothered
by the sediments.
In another nearby watershed, MacAleer Creek is also running very full and caused some flooding downstream in Lake Forest Park.

MacAleer Creek emerges from under the
bridge and rushes into LFP with
heavy flows

Check Dam structure on MacAleer Creek.
Creek water is over topping the banks of the upstream section.
Residents and LFP City officials have been striving for many years to address the flooding and water quality problems which are caused by the stormwater runoff that impacts both MacAleer and Lyon Creek. Property damage, wildlife habitat and water quality issues are the subject of the Lake Ballinger Forum. Five Cities have been meeting for several years to work on solutions to these stormwater problems.

Also Lake Forest Park is trying to address these problems from several angles. Their Environmental Quality Commission and Urban Forests Task Force has championed a new Tree Ordinance which is based on increasing Tree Canopy. They acknowledge the need to utilize trees as a part of their infrastructure to combat stromwater problems.

There is clearly still a lot of work to be done to really get these problems under control, when the bigger storms come. It will take a lot of courage and concerted effort for municipalities to really get these problems under control. 

Low Impact Development (LID) is prescribed as the solution. It is mandated in the stormwater standards.
Let's look honestly at getting the ball rolling to put this technology to work. This is one way to bring green jobs to our communities to address a serious problem.

4 comments:

  1. Thank you, Janet, for all of these excellent photos and the valuable documentation of the recent storm event. Your blog is always interesting, so I deeply appreciate all the time you put into creating it.

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  2. when were these photos taken? When was the "big" storm? Sunday morning?

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  3. Thank you, Janet. There is great feedback on the "green tool kit" used for the designing of Aurora Avenue improvement project in the 2nd and 3rd miles.

    Let's keep advocating for the zero/low impact development standards to reduce the impacts of these 50-year and 100-year storm events that seem to occur more frequently.

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  4. Thanks all! These were taken on Sunday morning. The heavy rain was overnight mostly and had been building up all week. We had 2 - 3 inches in the area.

    Yes a good wake-up call on stormwater planning for Aurora. I didn't get over to Echo Lake that day, but it certainly has plenty of problems which also lead into MacAleer Creek

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