Creating Tools for Urban and Suburban Communities to Reduce Flooding and Improve Water Quality in New Jersey

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1 Creating Tools for Urban and Suburban Communities to Reduce Flooding and Improve Water Quality in New Jersey Christopher C. Obropta, Ph.D., P.E. October 25, 2016

2 Water Resources Program Our Mission is to identify and address community water resources issues using sustainable and practical sciencebased solutions. The Water Resources Program serves all of New Jersey, working closely with the County Extension Offices.

3 Environmental County Agents The Environmental County Agents teach people new skills and information so they can make better informed decisions and improvements to their businesses and personal lives. Michele Bakacs, Middlesex and Union Pat Rector, Morris and Somerset Amy Rowe, Essex and Passaic Mike Haberland, Camden and Burlington Sal Mangiafico, Salem and Cumberland Steve Yergeau, Ocean and Atlantic

4 Water Resources Program The Impact of Development on Stormwater Runoff 10% 20% 30% 55% More development More impervious surfaces More stormwater runoff

5 Reference: Tom Schueler and Lisa Fraley-McNeal, Symposium on Urbanization and Stream Ecology, May 23 and 24, 2008

6 Green Infrastructure an approach to stormwater management that is cost-effective, sustainable, and environmentally friendly Green Infrastructure projects: capture filter absorb reuse stormwater to maintain or mimic natural systems and treat runoff as a resource

7 Green Infrastructure includes: green roofs rainwater harvesting tree filter/planter boxes rain gardens/bioretention systems permeable pavements vegetated swales or bioswales natural retention basins trees & urban forestry green streets Parker Urban Greenscapes

8 The Hydrologic Cycle

9 It s all about managing impervious surfaces! Eliminate it! Change it! Disconnect it! Reuse it!

10 Eliminate it!

11 Underlying stone reservoir Change It! Pervious Pavements Porous asphalt and pervious concrete are manufactured without "fine" materials to allow infiltration Grass pavers are concrete interlocking blocks with open areas to allow grass to grow Ideal application for porous pavement is to treat a low traffic or overflow parking area

12 Pervious Pavements FUNCTIONS COMPONENTS Manage stormwater runoff Minimize site disturbance Promote groundwater recharge Low life cycle costs, alternative to costly traditional stormwater management methods Mitigation of urban heat island effect Contaminant removal as water moves through layers of system

13 Pervious Pavement

14 Pervious Pavements

15 Disconnect It!

16 For 1.25 inch storm, 3,811 cubic feet of runoff = 28,500 gallons 1 acre directly connected impervious cover Total drainage area = 3 acres 2 acres pervious cover Runoff Direction Stormwater Inlet

17 For 1.25 inch storm, 581 cubic feet of runoff = 4,360 gallons 1 acre directly connected impervious cover Total drainage area = 3 acres 2 acres pervious cover Runoff Direction Stormwater Inlet

18 Volume of Runoff Design Storm Connected (gallons) Disconnected (gallons) Percent Difference 1.25 inches (water quality storm) 28,500 4,360 85%

19 Simple Disconnection

20 Disconnection with Rain Gardens Rooftop runoff is now disconnected from flowing directly into the storm sewer system

21 Lots of Rain Gardens

22 Reuse it! Disconnect your downspout by installing a rain barrel Impervious area is now disconnected from flowing directly into the storm sewer system

23 So Many Barrels to Choose From

24 Or Larger Rainwater Harvesting Systems

25 Water Resources Program

26 Water Resources Program Raritan River Basin 1,100 square miles in size Portions of seven counties and 98 municipalities Frequent localized flooding Impaired for total suspended solids (TSS) and phosphorus Impaired aquatic community The goals of this project are to enhance the climate resilience of the municipalities within the Raritan River Basin study area by providing each municipality with a plan to reduce stormwater runoff.

27 Water Resources Program Impervious Cover Assessment

28 Impervious Cover Assessment Water Resources Program Analysis completed by watershed and by municipality Use 2007 Land Use data to determine impervious cover Calculate runoff volumes for water quality, 2, 10 and 100 year design storm and annual rainfall Contain three concept designs

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30 Water 10.1% Wetlands 1.4% Barren Land 4.2% Forest 5.2% Urban 79.1%

31 Mixed Urban 8.7% Recreational Land 5.6% Transportation/Infrastructure 6.1% Commercial 13.2% Industrial 26.2% High Density Residential 40.2%

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33 Watershed Arthur Kill Waterfront Total Area (ac) Impervious Cover (ac) % 1, % Raritan Bay % Lower Raritan River Woodbridge Creek 1, % % Total 3,312 1, %

34 Subwatershed Arthur Kill Waterfront NJ Water Quality Storm (MGal) Annual Rainfall of 44" (MGal) 2-Year Design Storm (3.3 ) (MGal) 10-Year Design Storm (5.0 ) (MGal) 100-Year Design Storm (8.2 ) (MGal) Raritan Bay Lower Raritan River Woodbridge Creek Total ,

35 Water Resources Program IMPERVIOUS COVER ASSESSMENT (ICA) Analysis completed by watershed and by municipality Use 2007 Land Use data to determine impervious cover Calculate runoff volumes for water quality, 2, 10 and 100 year design storm and annual rainfall Contain three concept designs

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37 How do we identify potential sites? Water Resources Program EPA SWMM model of the drainage of each municipality Evaluate the existing stormwater sewer system and stormwater control measures (SCMs) Prepare GIS maps of the storm sewer system and existing SCMs Install flow meters throughout the municipality and storm sewer system Model overland flow, stormwater sewer system, and SCMs Use long-term data to calibrate and validate the model Identify where SCMs are needed Prioritize sites Complete cost benefit analysis Secure property owner permission

38 No! WE LOOK HERE FIRST: Schools Churches Libraries Municipal Building Public Works Firehouses Post Offices Elks or Moose Lodge Parks/ Recreational Fields Water Resources Program 20 to 40 sites are entered into a powerpoint: Site visits are conducted

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43 Total Area Impervious Cover Total Area Impervious Cover Municipality County (ac) (ac) (%) Municipality County (ac) (ac) (%) Delaware Twp Hunterdon 23, % Woodbridge Twp Middlesex 15,368 5, % East Amwell Twp Hunterdon 18, % Englishtown Boro Monmouth % Flemington Boro Hunterdon % Freehold Boro Monmouth 1, % Franklin Twp Hunterdon 14, % Freehold Twp Monmouth 24,881 2, % Raritan Twp Hunterdon 24,094 2, % Manalapan Twp Monmouth 19,759 2, % 54 Municipalities totaling 831 square miles Readington Twp Hunterdon 30,612 1, % Marlboro Twp Monmouth 19,477 2, % Dunellen Boro Middlesex % Millstone Twp Monmouth 23,800 1, % Total population is 1,346,436 (15.3% of NJ) East Brunswick Twp Middlesex 14,340 3, % Bound Brook Boro Somerset 1, % Edison Twp Middlesex 19,611 6, % Branchburg Twp Somerset 12,970 1, % Helmetta Boro Middlesex % Bridgewater Twp Somerset 20,711 3, % % of Impervious Cover ranges from 2.1 to 52.6 Highland Park Boro Middlesex 1, % Franklin Twp Somerset 29,998 4, % Jamesburg Boro Middlesex % Green Brook Twp Somerset 2, % Average Impervious Coverage is 26.6% Metuchen Boro Middlesex 1, % Hillsborough Twp Somerset 20,711 3, % Middlesex Boro Middlesex 2, % Manville Boro Somerset 1, % Milltown Boro Middlesex 1, % North Plainfield Boro Somerset 1, % Monroe Twp Middlesex 26,989 3, % Raritan Boro Somerset 1, % New Brunswick City Middlesex 3,686 1, % Somerville Boro Somerset 1, % North Brunswick Twp Middlesex 7,860 2, % South Bound Brook Boro Somerset % Old Bridge Twp Middlesex 24,754 3, % Warren Twp Somerset 12,563 1, % Perth Amboy City Middlesex 3,312 1, % Watchung Boro Somerset 3, % Piscataway Twp Middlesex 12,131 3, % Berkeley Heights Twp Union 4,004 1, % Sayreville Boro Middlesex 11,252 2, % Fanwood Boro Union % South Amboy City Middlesex 1, % Mountainside Boro Union 2, % South Brunswick Twp Middlesex 26,243 4, % Plainfield City Union 3,819 1, % South Plainfield Boro Middlesex 5,331 2, % Scotch Plains Twp Union 5,796 1, % South River Boro Middlesex 1, % Springfield Twp Union 3,308 1, % Spotswood Boro Middlesex 1, % Summit City Union 3,868 1, %

44 Water Resources Program Impervious Cover Reduction Action Plan

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46 Water Resources Program

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55 Water Resources Program Final Thoughts Plans promote action Plans are a conduit for funding Impervious Cover Reduction Action Plan provide sites for developers to offset impacts Wide range in cost of projects (Eagle Scout Projects to Stimulus Money Projects) Foundation for stormwater utilities, watershed restoration plans, and integrated water quality plans Plans are quick and easy to develop

56 Questions? Christopher C. Obropta, Ph.D., P.E.