A Clearer Weir!

Posted By Dwight on September 2, 2010

The willows in the center of the photo are blocking the low-flow channel; to the left is the freshly mowed high-flow channel.

Shortly after our meeting with King County and the Army Corps of Engineers, I went over to the weir to see if the clearing had started–and it had.
The county took an important first step in resolving the water flow problem from Lake Sammamish into the Sammamish River. These photos show the results of the mowing operation that began late last week.
Still a concern are the willows and additional sediment accumulation that might restrict the higher flows come winter. On September 9 we’re meeting on-site to discuss future maintenance and what other steps need to be taken to ensure that the lake will continue to drain during higher flows.
As for right now, however, the water–and King County–are moving in the right direction!

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Government & Citizens Work on Sammamish Water Level–Together

Posted By Dwight on August 20, 2010

It’s a rare and wonderful thing when concerned citizens, noted experts, and members of Federal, State and Local government sit down together and take concrete steps to fix a big problem.

Yesterday was one of those meetings.

Followers of this blog know that I’ve been actively involved in a variety of issues concerning Lake Sammamish. The high water levels that occurred earlier this summer have been a focus of my efforts.

The water was not flowing properly from the lake through the outlet at the Sammamish River, and it caused major problems for people who both live on this lake and use it for recreational purposes.

Yesterday a number of lake residents, leaders from local municipalities, officials from King County, the Army Corps of Engineers and representatives of state government sat down and had a meeting of the minds–and formulated the next steps to fix the water flow.

The work is only beginning, and we have a way to go, but we are on a positive path–thanks to all involved.

This is the way government is supposed to work!

Dwight

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August Update: Shoreline Master Plans Move Forward

Posted By Dwight on August 19, 2010

Approved: The City of Kirkland’s Shoreline Master Plan (SMP) has been approved by the State Department of Ecology. It includes regulations for a number of new uses as well as general performance standards, and you can see the highlights of the plan by clicking here.

Seeking Local Approval: The City of Bellevue’s proposed SMP is in the “Local Approval” phase, which needs to be completed prior to submitting the plan to the state in the fall. Take a look at the working draft here.

Upcoming Public Hearing: The City of Sammamish reports that the Department of Ecology will hold a public hearing—tentatively scheduled for October 7—on the city’s proposed SMP. You can get schedule updates and see the proposed plan here

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Wood Ducks from Dump to Jump

Posted By Dwight on July 22, 2010

Last year I put up six wood duck boxes, and early this spring I went out to check on them, clean them out and set up a few new boxes. Wood ducks are generally shy and they usually nest in tree cavities, so I feel lucky if I get a good view of one.

In two of the existing boxes I found fresh eggs, and within weeks there were two pair of wood ducks parading past our house daily.

I thought it was very late in the season, they should be brooding by now, maybe the nest boxes are all full? That weekend I made more boxes, and put one up right in front of my house and another at my neighbors. Within a week we had a duck in our box and about two weeks later our neighbors had “tenants” as well.

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The drakes hung around for a while, and the hens were very discrete. We rarely saw her enter or leave the house. One day I noticed the drake sitting on the fence, and the hen sitting on the house, just hanging out. It was kind of unusual.

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After a while I noticed there was a second hen, a hooded merganser, who flew up and stuck her head in the house. Our wood duck, on the roof, forced this interloper down into the drink. Clearly the merganser was interested in taking over the nest. They jockeyed for position, up on the roof, around the water, over on the fence, the ladies doing all the negotiating, a peck or hiss now and then, with the drake just staring straight ahead.

The turf war heats up

The turf war heats up

The male jumps off the fence

The male jumps off the fence

duck-winnerFinally the wood duck hen went in the house turned right around and sat half in and half out blocking the entrance. The hooded merganser was beat, and she flew away. Seconds later the wood duck hen took off and the drake followed.

I had not checked the nest for a while, so I decided to go have a look. As I set up my ladder I bumped the duck house and a third hen came flying out of the house! Our duck was sitting on her eggs the whole time. No wonder the other hen did not stay in the house for long, she probably got a nip in the butt from the duck on the eggs!

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When I opened the house there were 24 eggs, fresh and clean as any you might see at the grocery store. A typical clutch is 10-15 eggs, so we had at least two ducks “dumping” in our nest. While not ideal conditions, our hen hatched out 9 ducklings from the batch.

My neighbor’s eggs hatched about a week later. They had a dozen in the nest, and I just happened to see six fluff balls right after they jumped, following their mama on a maiden voyage toward the lily pads.

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Wall of Willows

Posted By Dwight on July 22, 2010

It appears to me that work which was done at the Sammamish weir in 1998 may have had the unintended consequence of plugging the outlet to Lake Sammamish.
It is clear to me that the vegetation below the weir is now the critical factor for draining the lake, this vegetation is more restrictive than the weir itself in all but the lowest summer flow rates.

How could this have happened? Here is my take on it:

Prior to 1998 the weir was at elevation 25.5, mostly level with a wide and shallow outlet to the transition zone. The low flow channel just downstream of the weir was open and about 50′ wide (my estimate from the 1991 photo posted below).

Two improvements for fish passage in 1998 narrowed the low flow channel; a notch was created in the center of the weir, and a log sill with a 4′ wide notch was added just below a small fish resting pool below the weir. It seems that these two improvements narrowed the low flow channel and allowed the willows to grow together into the channel in the low flow summer months. Now it is hard to identify any low flow channel at all. The view from the weir downstream is a “wall of willows” where the low flow channel once was. This has become the limiting factor for the outflow of Lake Sammamish in low, high, and normal flow conditions. It is great to do things which are good for fish passage, but this work may have also caused lake levels to be substatially higher. That was not part of the plan.

I hope that this situation will be quickly rectified so that the lake flood levels can be better contoled next year.

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Sammamish River 1991

Posted By Dwight on July 22, 2010

This is the low flow channel July 15, 2010

This is the low flow channel July 15, 2010

[caption id="attachment_204" align="alignleft" width="824" caption="note the open low flow chanel and the mowed high flow area"]note the open low flow chanel and the mowed high flow area[/caption]

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Study of Flow Rates at Lake Sammamish – trending down

Posted By Dwight on July 3, 2010

lk-samm-annual-outflow-averages-at-weir-bar-graph

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A Look at Why Lake Sammamish is so High

Posted By Dwight on June 29, 2010

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If you’re wondering why the water level on Lake Sammamish is at an all-time high, take a look at this video. 

In it you’ll see the area around the weir that sits between Lake Sammamish and the Sammamish River.  This small area is the only outlet for Lake Sammamish.  It looks like the vegetation below the weir is backing the water up over the top of the weir and restricting the flow at the outlet. 

I have asked both King County Flood Control and the Army Corp of Engineers why the lake is so high this year; it will be interesting to see what they have to say.

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Here is how one family is affected by the high water:

Posted By Dwight on June 26, 2010

no-party-here-4th-of-july

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Posted By Dwight on June 26, 2010

usgs-chart-june-2010-high-water-and-4-year-median

The above graph shows that we had some very high winter lake levels this year, but we were trending down to typical seasonal levels. Then Lake levels really spiked in April and June, quickly rising and slowly falling.

The blue line is this year, the brown line is an average of the previous four years, which shows an average June 1 level at about 26.5.

I Have asked both King County Flood Control and the Army Corp of Engineers why they think we are have such historic high levels. Although we have had a wet Spring, it has not been extreme, like the lake level has. I will report back as I learn more.

Dwight

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