Municipal Stormwater Management: Does Your Town Need More than the Minimum?

Transcription

1 Municipal Stormwater Management: Does Your Town Need More than the Minimum? ANJEC Congress Friday, October 9,

2 The existence of a regulation indicates a failure of design. William McDonough

3 The Rules In 2004, the N.J. D.E.P. promulgated revised stormwater rules (N.J.A.C. 7:8 and 7:14A, Subchapter 25) that changed the way we treat stormwater run off in New Jersey. To read and print out the Rules go to: These new rules are minimum standards chiefly administered by municipalities that have adopted the new rules verbatim as part of their local ordinances.

4 Local Options Municipalities can simply adopt the minimum standards. Most did. BUT Municipalities may amend these minimum standards to meet local needs by altering their local ordinance. Changes have to be at least as protective as those in the minimum standards but may be more protective or different. Changes must be approved by the N.J. D.E.P.

5 Why Are We Having This Discussion? New Jersey is the most densely populated state with and average population density of 1205 people per square mile. This is an average density. Some parts of the State are much more dense: Hudson County, 13,882 pc/sq. mi., while others are less dense: Salem County, pc/sq. mi. This dense population has created developed areas, many of which have no stormwater controls at all. There are large areas of impervious surfaces such as roads, parking, sidewalks and rooftops, in some places approaching 100% of the land surface. Precipitation falling on impervious surfaces produces large volumes of run off at a faster rate than natural land cover. Even grass can produce large amounts of run off if the underlying soil is compacted

6 New Jersey s Population Density: Uneven Distribution

7 Impervious Cover Continues to Grow and Existing Run off Remains Unaddressed. New Jersey s total impervious footprint as of 2007 was 508,681 acres or nearly 800 square miles of rooftop, concrete and asphalt. Other large areas are compacted soil Run off from about 11% of the State s land area remains largely unaddressed. During the period, New Jersey added 21,348 acres (33.4 square miles) of additional impervious surface. Statewide, this is an annual rate of 4,270 acres of impervious surface increase per year or 9 football fields of new impervious surface per day (including end zones).

8 Resulting In Annual Increased Runoff of: 5,454,263,223.1 gallons per year statewide* *Assuming: Run off from impervious surfaces is 98% of an annual rainfall of 48 Inches. This is an annual increase large enough to cover 16,571 acres of land ( about the size of Bernards Twp.) to a depth of one foot.. Climate change may increase this volume and flooding frequency

9 A one size fits all approach using minimum standards is highly unlikely to produce good results in all cases, but, even the minimum standards, when properly implemented, will result in improvements in water quality and control of rate and volume of stormwater, but Many municipalities are not properly implementing even the minimum standards. N.J.D.E.P. is currently proposing to weaken the rule.

10 Implementing the Existing Rule Your municipality may not be fully aware of its responsibilities under the stormwater rules. Help is available for you environmental commission and planning board with the Stormwater e learning Tool developed by Rutgers Cooperative Extension, Water Resources, N.J.D.E.P and ANJEC. The tool is available at: lofficialtraining/e Tool%20(FINAL)/story.html?usp=send_form Or Google rutgers stormwater e learning tool

11 Implementing the Stormwater Rule The Stormwater e learning Tool is a narrated interactive on line training aid that has three parts: I. Introduction to Stormwater Management II. Regulations and Best Practices III. Compliance Resources The tool takes about 45 minutes to run but because it is interactive, it may take longer.

12 Implementing the Stormwater Rule ANJEC strongly recommends that environmental commissions, planning boards, boards of adjustment, elected officials, municipal engineers, municipal attorneys and planners review the tool. Commissions should do this at a meeting with the whole commission, and the planning board liaison present but the tool can be accessed and used at any time.

13 Sample E Tool Questions: Non Structural Strategies : 1. Has the applicant identified the Nonstructural Stormwater Strategies which are incorporated into Project and where they are located on the plans? If YES go to question #2. If NO to Question #3. 2. Have the strategies been integrated into the design to the maximum extent practicable? 3. Has the applicant submitted justification to why none of the nine strategies can be incorporated into the site design (environmental, engineering, safety reasons)?

14 9 Non Structural Strategies (1 4) 1. Protect areas that provide water quality benefits or areas particularly susceptible to erosion and sediment loss. 2. Minimize impervious surfaces and break up or disconnect the flow of runoff over impervious surfaces. 3. Maximize the protection of natural drainage features and vegetation. 4. Minimize the decrease in the preconstruction time of concentration.

15 Non Structural Strategies Minimize land disturbance including clearing and grading. 6. Minimize soil compaction. 7. Provide low maintenance landscaping that encourages retention and planting of native vegetation and minimizes the use of lawns, fertilizers, and pesticides. 8. Provide vegetated open channel conveyance systems discharge into and through stable vegetated areas. 9. Provide preventative source controls.

16 Implementing the Stormwater Rule Part III, Compliance Resources gives you specific questions to ask applicants during the site plan review process. Non structural stormwater strategies General stormwater run off calculations Water quality Water quantity Structural/maintenance requirements Safety requirements Groundwater recharge requirements

17 Using these questions during site plan review, and prior to completeness determinations is the key to effective implementation of the stormwater rule.

18 Going Beyond the Minimum Standards Before proposing changes to your ordinance, read and understand the Rule! For example, the Rule applies only to Major Development. "Major development" means any "development" that provides for ultimately disturbing one or more acres of land or increasing impervious surface by one quarter acre or more. Disturbance for the purpose of this rule is the placement of impervious surface or exposure and/or movement of soil or bedrock or clearing, cutting, or removing of vegetation. Projects undertaken by any government agency which otherwise meet the definition of "major development" but which do not require approval under the Municipal Land Use Law, N.J.S.A. 40:55D 1 et seq., are also considered "major development. Think about how development is happening in your municipality. How many projects are major development and how many are below this threshold? Should it be smaller?

19 Building the Case: Impacts to Be Expected Physical Damage to Streams Surface Water Quality Deterioration Deranged Flows Biological Stress Groundwater Depletion Base Flow Reduction Increases In Water Temperature Overwhelmed Infrastructure (stormwater and CSOs) More frequent and higher floods in smaller storms

20 Impervious Surfaces

21 Biological Impacts

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24 Green Stormwater Infrastructure Practices Can: Increase shallow and deep groundwater recharge. Stabilize stream flows (base flows). Reduce run off percentages., unload CSS Reduce flooding. Reduce run off temperatures Improve both groundwater and surface water quality. Be cost effective and extend the life of existing stormwater and sewer infrastructure. Address urban heat island impacts and reduce energy consumption. Provide aesthetic and social enhancement.

25 If the Stormwater Rule is working, 1. Downspout Disconnection You Should Be Seeing

26 2. Soil Amendment: Compaction and Compost

27 3. Rain Barrels

28 4. Rain Gardens

29 5: Filter Strips

30 6. Vegetated Swales

31 7. Infiltration/Biofiltration Practices

32 8. Porous Pavement: Concrete, Asphalt, Pavers

33 More Porous Pavements

34 9. Water Harvesting: Bigger Than Rain Barrels!

35 10. Constructed Pocket Wetland

36 11. Tree Boxes

37 12. Street Trees/Afforestation

38 13. Green Roofs

39 Getting There Review ERI: Map Stormwater System Evaluate Master Plan Evaluate Stormwater Plan Evaluate Stormwater Ordinance Survey Physical Stream Conditions Educate Planning/Land Use Board and Elected Officials. Check Municipal Engineer s and DPW s Knowledge Support Legislation for Stormwater Utilities

40 Thank You! To download this presentation: ww.anjec.org David Peifer: x 13