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Monday, August 24, 2015

Storm water runoff--we have seen the enemy and it is us!

    This past week I had a chance to hike around Lake Elkhorn to learn about the nature around the lake and the efforts to manage the health of the lake.   The hike was sponsored by the Columbia Association and led by Ned Tillman.   Managing the health of our town's man made lakes is challenging with the amount of silt and nutrients that enter the lakes from our developed land.  The islands pictured above and below are just one small way that CA tries to filter some of the nutrients out of the lakes.  These nutrients come primarily from the fertilizers we put on our lawns.  

    The rain garden pictured below is another way that CA is trying to manage the storm runoff from the streams that flow into the lake.  I will talk a little more about rain gardens a little later in the post.

The warm temperatures and nutrient rich water make the growth of hydrilla an ongoing problem for our lakes.   
       The machine shown below is used to cut and remove the hydrilla that grows in our lakes. 
Much of the hydrilla is used by CA as organic material to be mixed with mulch and soil that is used by CA.

The Columbia Association has been piping in oxygen into the water to keep the water oxygen level sufficient to support the needs of fish in the lake.

     There are very few natural lakes or ponds in Maryland and the United States for that matter.  Our lakes were created by damming up streams that flowed through marsh areas.  The dam pictured below at one end of Lake Elkhorn it what created the lake.

    When we pave over land to build parking lots and drive ways a storm drain system has to be built to channel the rain water away from these lots.

    Ned pointed out in the picture below how one storm drain dumped water into a small stream that leads down to Lake Elkhorn.  Unfortunately the stream is too small to handle the amount of water dumped into it and the soil is eroded into the lake.

   Below is the small delta that is being created in the lake from the soil flowing into the lake from the stream.

   Ned's knowledge of geology was useful in explaining the rock formations that are at one end of the lake.  The large rocks pictured behind him are mostly sedimentary rocks made from compressed sand that washed away from the mountains that once were located where we live.  They were higher than today's Himalayas.  The soil erosion from these mountains ended up flowing east and creating the Eastern Shore and the Continental Shelf off the Atlantic Coast.

    Below is a vein of granite squeezed between two layers of sedimentary rock.

     It is not hard to see examples of the granite like pictured below as you go around the lake.

      The area around the BG&E power lines at one end of the lake creating a healthy marsh land for ecological and wildlife benefit shows how development doesn't have to be negative.

     Berries on the bushes below are an important aspect of any wildlife habitat.

     As mentioned earlier CA can only manage a part of the problem with soil erosion and storm runoff.  We as homeowners can often do damaging things that increase the problems.  The owners of the home below have cleared trees and our shrubs that will increase the amount of storm water runoff that is only a few feet from the lake.

      So the message of this post is that CA is at the "small end of the funnel" to control storm water runoff that is creating the problems in our lakes.   We as homeowners are at the "large end of the funnel" with our yards that are a major source of the problem.  If we we continue to fertilize our yards and not control the storm water runoff through installing rain gardens CA will never be able to create the healthy lakes that we all want to enjoy in Columbia.   Fortunately CA has a program that will pay for the majority of the cost to install a rain garden.  Additionally Howard County will rebate $250 to the homeowner for installing a rain garden.   For very little out of pocket cost homeowners in Columbia can have a beautiful rain garden like the one below for very little cost.

      Here is the link to the CA rain garden cost share program.   John McCoy explains the program in this You Tube video.  Time to do our part as homeowners.


1 comment:

Ned Tillman said...

Great photos and very good coverage of a very important aspect for our community.