Wednesday, March 14, 2012

Feeding the Lake


In 1990 then-mayor Al Fowler told me of his vision to create holding ponds for the water that fed the lake. Silt in the water would settle, resulting in cleaner water in the lake, and thus less sedimentation.

I'm happy to say Al's dream has come at least partly true.

I'll lead off with material from a November post from The Dredge Report.



Until a few weeks ago, the flow into the lake was controlled by a contraption consisting of a Stop sign wrapped in a plastic bag. Low-concept; low-design; very effective. As the dozens of residents witnessed on October 30 with the turning of the red wheel (see photos below), the city now has something even better than a Stop-In-A-Bag: three separate valves that attenuate water flow into the lake and the creek.
I'll show the red wheel in a bit, but first take a look at this little dam. It's located at the far edge of the eastern (upstream) wetlands.


Below the dam Snapfinger Creek take a 90-degree turn and flows along the edge of the wetland, eventually crossing beneath Spruce and running beside the north shore of the lake to the western wetlands.

A metal grate keeps large objects from blocking an intake pipe at the dam.


The red wheel is just about at the vantage point of the photo. It looks like this:



 The wheel regulates water intake to the lake.

Below the sluice there's a  five-foot wide channel that runs maybe 100 yards:




At the end are two more sluices.


The wheel on the left controls water input into a trough that runs to the lake.


The wheel on the right controls intake to a series of pond that flow between the path and Snapfinger Creek.


The watercourses come back together here, about 100' from Spruce Drive:


... and flow through a trough to the lake.


Water enters the lake through this pipe:


It's quite an improvement from the stop sign, huh?

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