State Water Resources Research Institute Program
Project ID: 2009NY119B
Title: Performance of a Retrofit Stormwater Treatment System in an Institutional Setting, New Paltz, NY.
Project Type: Research
Start Date: 3/01/2009
End Date: 2/28/2010
Congressional District: 22
Focus Categories: Hydrology, Floods, Law, Institutions, and Policy
Principal Investigators: Geohring, Larry D (Cornell University); Richards, Brian; Steenhuis, Tammo; Vanucchi-Hartung, Jamie
Federal Funds: $ 0
Non-Federal Matching Funds: $ 37,634
Abstract: Stormwater has become a major regulatory emphasis in the US as problems of flooding, stream erosion and sedimentation, stream habitat destruction, and water quality degradation persist in urban and suburban areas. Stormwater has a documented major impact in the Lower Hudson Basin. Of the area's nearly 9000 river miles, over 20% are on the State's Priority Water Bodies List because they have or are threatened by water quality problems. Urban/Storm Runoff is listed as a major cause for the largest mileage of any cause (by far) in the two most severe classes "precluded" and "impaired" (NYS DEC, 2008). Folding in the third severity class "stressed", one third of the impaired 1800 miles have developed area stormwater as a contributing cause.
Impervious surface that is connected to streams via overland paths or pipes, such as storm sewers, is recognized as a dominant culprit. Effects on stream health become notable with as little as 10% imperviousness in an area (Arnold and Gibbons, 1996). Effects on the receiving water include channel scour by high transient velocities, quick delivery of sediment and debris accumulated on the impervious surface and pipe network, and delivery of pollutants that might have sorbed or been segregated biologically, had they been deposited on vegetated soil instead of being discharged to a rapid drainageway.
Mitigating measures for new development very often try to reduce impervious surfaces, particularly connected ones. This, together with stormwater velocity reduction and infiltration at optimal sites on a property, lets new development have a much lower impact on streams than older development (NRDC, 2006; Prince George's County, 1999). Land that is already developed represents a large share of total stormwater impact in cities and suburbs of the lower Hudson valley. In mature communities having stormwater impact problems, developed lots may be able to be retrofitted with some of the toolbox but lots may not have much space, there may be no good infiltration locations, topography may be adverse, and impervious surface may be unable to be reduced (Center for Watershed Protection, 2003, chapter 9 on redevelopment).
There is an existing redevelopment site in the lower Hudson region that offers a case study of what is possible for stormwater within site constraints -- the NYS DEC Region 3 office in New Paltz. Some of the stormwater handling was upgraded when the building was expanded recently, but there are some shortcomings of the site and the drainage design that hamper performance.
Progress/Completion Report, 2009, PDF