Sediment Ponds

 A sediment pond to the SW of Old Middleton Rd.

Settling basins or sediment ponds are an important protection for our lakes.  They keep litter, sediment, and nutrients out of our lakes.  The ponds are dredged at intervals to remove the accumulated sludge.

With proper landscaping, trails, and planting, basins can be beautiful green places within the city.  This is a potential that hasn't been realized.  More photos.

Basins are an ideal solution for new developments, where the required space can be planned for.  But the developed parts of Madison, new basins can be a problem.  The City has a tendency to prefer basins to more innovative solutions, like rain gardens, because basins don't involve a lot of interaction with the public.

Some of the problems with basins...
  • Construction of basins causes serious construction site erosion. Example
  • Often involves cutting many trees
  • Basins often can't replenish groundwater, like rain gardens can
  • Require large amounts of land
  • Require maintenance to keep working
Wherever possible, we favor rain gardens over basins in parts of Madison that are already developed.  Obviously, for rain gardens to do the job of one large basin, there have to be thousands.  That's great--they will beautify our city.

Around the UW Arboretum, a number of sediment ponds have failed over the years.  Several of these are being reconstructed--generating some controversy.  Generally, we support the reconstruction plans for these basins because they are existing basins--and they must be maintained to work properly.