Recent Projects

On this page you will find recent projects that the UNH Stormwater Center has been involved in. They are searchable by title* or by the date in which the project was completed.

* For the Title field, you can enter a word or partial title listing or leave it blank and filter your search by Date only.

Porous Pavement Rehabilitation Project

Oct 2019

The UNH Stormwater Center in cooperation with Triverus and UNH Facilities conducted a product demonstration and subsequent quantification of the effectiveness of an enhance vacuuming technology by Triverus called the municipal cleaning vehicle.  Overall, the restoration effort was extremely successful.  Our research supports further exploration of restoration activities followed by more routine operation and maintenance such as vacuum sweeping twice per year.  This data also reveals some significant differences in the pollutant partitioning between the liquid and solid fractions of the removed materials.  It underscores the importance, particularly in nitrogen sensitive areas, of properly treating the removed waste materials.

You can download the final report here: ...

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Berry Brook Project

Jan 2018

The Berry Brook project in Dover NH is complete!  This partnership between NHDES, UNHSC and the City has reduced the effective impervious area in the 185 acre Berry Brook urban watershed from 30% down to 10%.  This unique partnership between academics, regulators and committed city staff has reduced best management practice implementation costs, increased the effectiveness, and led to more maintainable stormwater management systems. Combined, this project and these installations reduced pollutant loading of suspended sediment, phosphorous and nitrogen (total) by 17,514, 68 and 354 pounds per year, respectively.

The final report is available at:  Berry Brook Final Report

A more narative...

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Undersized GI System Performance

Feb 2016

This report details results from two years of study of two undersized stormwater control measures.

For a short executive summary click here:  Executive Summary

For the full report click here:  Full Report



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Stormwater Standards for the future

Sep 2015

UNHSC, in collaboration with VHB, SRPC and the Town of Durham recently completed a study modeling the pollutant load reduction potential of simple stormwater regulations.  The goal of this study was to evaluate the net effect that enhanced local stormwater regulations could have on minimizing future pollutant load increases from future impervious cover growth in the Oyster River watershed in New Hampshire.  As future development and land use changes are inevitable, early adoption of enhanced local stormwater regulations provides the greatest opportunity to minimize increased pollutant loading from future development.  Model stormwater regulations developed for the Southeast Watershed Alliance (SWA) in December 2012 provide a template for enhanced stormwater regulations that address...

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Greenland Mall, Packard Development and the Conservation Law Foundation, Greenland, NH

Jun 2015

In 2007, Packard Development, the Conservation Law Foundation, UN HSC, and Gove Environmental Services partnered to negotiate a Brownfields redevelopment proposal that protected receiving water quality.  The proposal was accepted, and the current installation—which includes three franchise stores and is estimated to accommodate nearly 10,000 vehicles daily—uses porous asphalt parking lots and subsurface gravel wetlands as anchors of the stormwater management plan.  The development was completed in 2009 and UNHSC continues to monitor the active commercial site for overall stormwater quality performance.  Five years of monitoring has demonstrated that runoff from the site consistently surpasses that of the receiving stream, Pickering Brook.

In 2014 this seven year monitoing...

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Cold Climate Performance Study of a Permeable Interlocking Concrete Pavement System in Durham, NH

Jun 2015

University of New Hampshire Stormwater Center (UNHSC) completed a two year field verification study of a permeable interlocking concrete pavement (PICP) stormwater management system. Monitoring took place from October 2010 through April 2012 on the University of New Hampshire (UNH) main campus in Durham, NH.  Volume reduction and subsequently pollutant mass removal exceeds 95% for all pollutants measured including sediment (TSS and SSC), metals (total Zinc - TZn), petroleum hydrocarbons (TPH), and nutrients (TP, ortho-P, TN, TKN, DIN = NO3, N02, NH4). Reductions in effluent concentrations were not observed for these same contaminants. This was presumably due to a concentration of pollutants caused by an exceptional volume reduction. Effluent volumes in any single event never exceeded 5...

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graphic with views of presentation topics

Forging the Link: Linking the Economic Benefits of Low Impact Development and Community Decisions

Aug 2011

This project documents, through a series of case studies, the advantages of Low Impact Development (LID) in the economic terms of how municipal land use decisions are commonly made.

In addition to the environmental and water quality benefits
for which Low Impact Development (LID) is so commonly
known, considerable economic, infrastructure, and adaptation
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Cover of Publication

2011 Road Management Plan for Brackett and Pond Roads, Wakefield, NH

Jun 2011

The purpose of the Road Management Plan is to address the declining water quality of Lovell Lake caused by runoff from Brackett and Pond Roads carrying sediment and phosphorus. Unimproved roads are commonplace in the Lakes Region of New Hampshire in an area with a substantial seasonal population. Unimproved roads and associated maintenance are well documented as major sources of sediment and phosphorus to surface water and may account for as much as 80% of the sediment load and 40% of the phosphorus load within a watershed. Studies have shown that during highly erosive storm events, sediment concentrations may be observed to exceed 100,000 mg/L with averages for gravel roads >3,000 mg/l (Clinton and Vose 2003) whereas a typical low use paved road would be ~100 mg/L (Hagen and Walker...

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students posing with construction equipment

Restoring Water Quality in the Willow Brook Watershed Through LID Retrofits

Nov 2011

By Robert Roseen1, PhD, PE, D.WRE, James Houle1, CPSWQ, Robert Dowling1, Melodie Esterberg2, Director, Lorie Chase3, Sally Soule4

1UNH Stormwater Center, 2Rochester Department of Public Works, Cocheco River Watershed Coalition3, NHDES Grant Manager4

Willow Brook is a tributary to the Cocheco River in the urban center of Rochester, NH. This small urban stream is impaired for Primary and Secondary Contact Recreation (e. coli). Its direct receiving waters, the Cocheco River, are impaired for Aquatic Life Use (benthic macroinvertebrates and habitat) as well as Primary Contact Recreation (e.coli). Likely sources are nonpoint source pollutants from urban stormwater...

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Development of hydrological mathematical models for LID-SWM systems

Development of hydrological mathematical models for LID-SWM systemsmn (2008 – Present)

Stormwater runoff is one of the primary stressors in coastal and freshwater systems. Because conventional stormwater management (SWM) cannot consistently meet the new standards for water quality, the focus in SWM shifted from solely hydrologic and hydraulic concerns with basically sedimentation and dilution of pollutants, to mass flux removal. The new approach, Low Impact Development - Stormwater Management (LID-SWM) has the potential to successfully address both quality and quantity aspects of stormwater runoff. As in any other field, planners, engineers, and legislators who develop SWM strategies need accurate tools based on sound scientific research in order to...

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