Cooperator: Wisconsin
Department of Natural Resources
Project Chief: Charles P. Dunning
Location: Dane County
Project Number: 9KH32
Period of Project: July 2001 to October 2007
updated 2/20/07
Problem
Starting in 2004, the state of Wisconsin has new construction performance standards
requiring reduction of runoff at a site through infiltration. However, there
is a lack of knowledge on how effective these infiltration practices will be.
The primary goal of this project is to understand the mass balance of a newly
constructed rain garden that is designed to meet state standards. A secondary
goal of this project is to help the Wisconsin Department of Natural Resources
(WDNR) establish a technical standard on implementation of infiltration practices.
Objective
The objective is to evaluate the effectiveness of the rain garden's ability to
infiltrate stormwater and to reduce the temperature of the runoff prior to spilling
into a cold-water trout stream. This will be done by installing surface and
subsurface equipment in each cell to calculate a volumetric mass balance.
Approach
The Lodi rain garden was constructed by The Wisconsin Department
of Transportations (WDOT) to buffer the stream from roadway runoff. This site
has three bioretention cells (A, B and C) connected by a perforated pipe. Each
cell has a bottom layer of 2 feet of coarse aggregate, then a 2-foot layer of
engineered soils, and a top layer that will be planted with a prairie seed mixture.
Surface and subsurface equipment will be
installed at the inlet structure and in Cell A to
measure water level, discharge, precipitation, and water temperature in the inflow
and outflow from the cell. A volumetric mass balance will be determined, and
inflow and outflow water temperatures will be compared to the water temperature
of the receiving stream.
Progress (January 2006 to June 2006)
Data collection continued for inflow, outflow, water temperature, and precipitation
with all data being stored in the USGS Watstore database. Real-time data were
available at: http://waterdata.usgs.gov/wi/nwis/uv/?site_no=431837089313401&PARAmeter_cd=00065,00060
Plans (July 2006 to December 2006)
Data collection will continue at the existing inflow and Cell A sites. “H” flumes
will be installed at the outlet drains from cells B and C to
quantify the volume of runoff that is produced from those cells. Data reduction
and interpretation will continue.
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