Wingra Watershed Planning–Infiltration Team Recommends 25% Increase in Infiltration to Groundwater


In the Lake Wingra Watershed in an average year, the surface (storm water) runoff  from rainfall, snow melt, and other sources, totals an estimated 82,968,732 cubic feet (or 620,649,732 gallons.)  Of this volume, 37,892,637 cubic feet (283, 456,637 gallons) is absorbed by the soil and returned to the groundwater.  The rest, over 50% or 45, 076, 095 cubic feet (337,192,607 gallons) goes down the drain, literally.    This surface runoff, laden with pollutants, goes down the nearest storm drain, runs through the city’s storm sewers and ends up in Lake Wingra.

This is also what soil destruction looks like.  Manitou Way resurfacing and new curbs and gutters installed fall of 2012 are already giving way above a storm drain.

Manitou Way resurfacing and new curbs and gutters installed fall of 2012 are already giving way above a storm drain.  Storm water entering this point flows into the Arboretum’s West Marsh and on to Lake Wingra.

At its meeting of June 28, 2013,  the Wingra Watershed Plan Infiltration issue Team recommended a 25 % increase in infiltration of current surface water (storm water) flow to the groundwater.  Achieving this goal would require the absorption and infiltration of an additional estimated 9,473,159 cubic feet of surface water.    Currently, an estimated 37,892,637 cubic feet, surface water/storm water flows into the groundwater.   These figures according to minutes of the meeting provided by Strand Associates.  The recommendation of increased infiltration will go to the full Wingra Watershed Plan Steering Committee for consideration.  Click here to see the Lake Wingra watershed GroundwaterBoundary and sewer shed boundaries.

Timeline

Although no target date for achieving this goal was set, those in attendance at the meeting, unanimously agreed that “increasing infiltration in the surface water watershed/groundwater watershed by an amount equal to 25 percent of the current estimated groundwater flow to the lake is an appropriate assumption for trying to meet the 25 percent increase in spring flow target from the Lake Wingra: A Vision for the Future document.”   The Lake Wingra vision document refers to a 2009 plan produced by the Friends of Lake Wingra (FoLW).

How To Get Involved

The Lake Wingra Watershed plan process is guided by a Steering Team and various issue teams (chlorides/infiltration; pollutant-sediment and phosphorous; pollutant-reduction opportunities; lake response model; social marketing–strategies; and social marketing–pilot project.   The membership of the Steering Committee is not published on the City web page, however it is confirmed by FoLW that two of its “Advisors to the Board”, David Liebl and Rebecca Power sit on the Steering Team.

Participation in the steering team or issue team meetings is apparently by invitation only (according to the FoLW  summer 2013 issue of Wingra Watershed News you may volunteer to participate in planning meetings by contacting them at:  info@lakewingra.org).   Meeting dates are published but location and time of meetings are not.

Participants in the June 28th Infiltration Team Meeting included:

Genesis Steinhorst, City of Madison

Sue Ellingson, Alderperson

David Liebl, Friends of Lake Wingra

Roger Bannerman, Wisconsin Department of Natural Resources

Mike Parsen, Wisconsin Geologic and Natural History Survey

Jon Lindert, Strand Associates, Inc.

Luke Hellermann, Strand Associates, Inc.

Several invitees did not attend the meeting, including a representative of the UW-Madison Arboretum and several representatives of the Friends of Lake Wingra plus an invitee from the University of Wisconsin.  (See minutes of the June 28 meeting for a complete list of invitees and attendees.

Major Sources of Increased Infiltration

Participants in the meeting indicated that increased groundwater recharge would come from increased infiltration of surface (storm water) runoff.  Potential infiltration sources are the MG & E infiltration facility at Odana Hills Golf Course (an estimated 5,852,867 cubic feet) and the proposed Arbor Hills Greenway Infiltration Facility (an estimated 3,726,084 cubic feet) would meet this 25% increase.  However, meeting notes indicate that participants expect that the MG & E infiltration contribution will decrease.  The Arbor Hills contribution is uncertain if only because the idea has, in recent history, met with resistance from City Engineering Division officials.  Therefore, the meeting participants agreed that additional infiltration facilities will be needed.

Why Do We Care?

  1. According to recent estimates based upon historical records, approximately 22 of the more than 30 springs that once surrounded Lake Wingra have been lost due to decreased groundwater flow.
  2. Base flow of water from Lake Wingra flows into Wingra Creek which supplies some fresh water to Lake Monona; during periods of drought this flow is interrupted.
  3. Natural springs are a natural feature of the landscape that are valued for their aesthetic beauty that enchants old and young.  The springs and their surrounds provide unique habitat for both aquatic and terrestrial plants and animals.

The City’s infiltration target of a 25% increase in recharge to the groundwater reflects  the FoLW Goal #2 in it’s 2009 plan, that called for “Restored Spring Flow–Cool, clean spring water replenishes the lake, and maintains year-round flows into Wingra Creek.  Lake Wingra becomes predominately replenished by groundwater.” (FoLW, 2009 p. 16.)

"Council Spring"  below the Kenneth Jensen Wheeler Council Ring on the north side of Lake Wingra.  Photo by Stephen B. Glass.

“Council Spring” below the Kenneth Jensen Wheeler Council Ring on the north side of Lake Wingra. Photo by Stephen B. Glass.

The Friends of Lake Wingra vision stated three measures or indicators, with supporting targets, that would indicate that spring flow has been restored.  In addition to the indicator of increased spring flow, and the target of a 25% increase in spring flow, the other sets of measures are:

1.  Indicator: “Increased flow rates.”  Target: A 25% increase in spring flow.”

2.  Indicator: “Restored flow of lost springs.”  Target: “Lost springs flowing year-round”.

3.  Indicator: “Base flow to Wingra Creek.”  Target: “Year-round flows from Lake Wingra into Wingra Creek.”

Infiltration Options

If the existing MG & E infiltration facility at Odana Hills Golf Course and the proposed Arbor Hills Greenway infiltration project will not be enough to meet the 25% increase in spring flow, what can be done?

Jon Lindert of Strand Associates , who is the lead project engineer, presented a series of infiltration options to meet the 25% increase goal.  These options included rain gardens, or bio-retention facilities at residential and non-residential properties, and porous or permeable pavement.  These will be considered by the Steering Team and acted upon in the future.

A new rain garden at Thoreau Elementary School, planted in the spring of 2012.

A new rain garden at Thoreau Elementary School, planted in the spring of 2012.

The Planning Process

According to the summer 2013 of the Wingra Watershed News, published by the Friends of Lake Wingra (FoLW), the Friends of Lake Wingra are working with Strand Associates, the City of Madison Engineering Division, and Bret Shaw of the UW-Extension to develop the first installment of a comprehensive Lake Wingra watershed plan.

“This plan will provide a framework that integrates our vision for Lake Wingra’s future with the diversity of Lake Wingra management activities. In addition, the plan makes it easier for anyone interested in the future of the Lake Wingra watershed to make a difference — no matter what your interest or skill set.” according to Rebecca Power who wrote a description of the plan process for the summer 2013 Wingra Watershed News.

If you would like more information about the planning process or to get involved, FoLW advises that you email them at:  info@lakewingra.org    However, you may get a “Mail Delivery Failed” notice as I did recently but Jim Lorman assures me that information inquires are being forwarded to him.

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About Steve Glass

The blogger is a restoration ecologist practicing and writing in the Midwestern United States.
This entry was posted in Bioretention facility, City of Madison Engineering Division, Friends of Lake Wingra, Green stormwater infrastructure, Groundwater, Lake Wingra, Lake Wingra Watershed, Lake Wingra Watershed management plan, Lake Wingra Watershed management planning, Madison lakes and beaches, Rain gardens, Storm water, Stormwater best management practices and tagged , , , , , , , , , . Bookmark the permalink.

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