ESD Training Citizen Advocacy for Greener, Cleaner Sites

Transcription

1 ESD Training Citizen Advocacy for Greener, Cleaner Sites Bruce Gilmore and Diane Cameron Thanks to: Anacostia Watershed Society Audubon Naturalist Society Keith Campbell Foundation Summit Fund of Washington Landscape Architect Andie Murtha Katherine Baer of American Rivers Tom Schueler of Chesapeake Stormwater Network

2 Environmental Site Design Training I. Stormwater Management Act of 2007 II. ESD Techniques for new development and redevelopment with examples from MD ESD Projects III. ESD Plan Review: the three steps IV Changes to the SWM regulations 2

3 What is Environmental Site Design (ESD)? An innovative form of stormwater management to: * Improve health of our waters * Create Wildlife Habitat * Beautify Neighborhoods * Save Money: Businesses, citizens and governments 3

4 ESD: The Goal Minimize impact of land development on our streams, rivers, Chesapeake Bay lakes, ocean waters Use natural and small scale/distributed stormwater practices to control runoff 4

5 I.The Stormwater Management Act of 2007: Mandate for ESD means using small-scale stormwater management practices, nonstructural techniques, and better site planning to mimic natural hydrologic runoff characteristics and minimize the impact of land development on water resources. Stormwater Management Act of 2007 Title 4, Subtitle 201.1(B) 5

6 The Need for ESD Development with poor stormwater control creates more runoff Adverse impacts: flooding, stream bank erosion, excess sediments, nutrients, toxics and pathogens 6

7 to mimic natural hydrologic runoff characteristics Sisters Creek rill, Cabin John High clay soils Leopold, Wolman, & Miller (1964) <0.6% of the annual precipitation ran off. Photo: Montgomery County DEP Cabin John Watershed restoration report. 7

8 Land Development of the Bay is the only pollution source that is increasing!! Between 1990 and 2000, MD's population climbed by 8%, while impervious cover increased by 41% and turf cover by 80% 2008: A school construction site in upper Sligo Creek demonstrates that lack of ESD and erosion prevention leads to sediment pollution. Trend: This will increase through 2030, while MD's population will grow by 17% 8

9 9

10 Existing vs new development 13% of Bay watershed is developed 5 million developed acres are largely untreated 2.5 million acres of new urbanized acres expected by million acres of redevelopment possible by 2030 Personal communication with Tom Schueler, Jan

11 Stormwater Management Act of 2007 Statutory Requirements 1. Implement ESD to the maximum extent practicable (MEP) 2. Local governments to remove impediments to ESD implementation from local planning and zoning and public works ordinances, codes. 11

12 SWM Act of 2007 (cont.) 3. Require developers to demonstrate that ESD has been implemented to the maximum extent practicable (MEP), and that standard best management practices have been used only where absolutely necessary. & Requirements 4 through 13 see handout. 12

13 What is Environmental Site Design to the Maximum Extent Practicable? (ESD to the MEP)? Definition: MEP means designing stormwater management systems so that all reasonable opportunities for using ESD planning techniques and treatment practices are exhausted and, only where absolutely necessary, a standard BMP is implemented. 13

14 14

15 II. ESD Techniques with examples from MD projects MDE Stormwater Manual Chapter 5 Planning Techniques Alternative Surfaces Non-structural practices Micro-scale practices Greenfield Sites Redevelopment Sites 15

16 ESD Site Planning Techniques Integrate Construction with ESD Integrate Construction with ESD Maximize Forest Canopy - map & preserve existing forest Go beyond minimum requirements of Forest Conservation Law Cluster the built environment Minimize imperviousness Shrink the footprint Minimize clearing and grading Reforest open areas throughout the site Note 7 16

17 Planning Techniques: Integrate Construction with ESD Only one-half of the site was cleared and graded at Auburn Village. 17

18 ESD Site Design Reduced Clearing & grading; Dual-use Swales, Berms, buffers Erosion Prevention Mulching, Blankets, Tackifiers seeding. Sed. Basin w/ baffles & Skimmers = 99.8% TSS Removal Efficiency. Sediment Control Chemical Coagulant Or filtration Via seep Berms, sand Filters, &/or Buffers. Turbidity Control 18

19 3. Conserve Soils and Natural Contours ESD Construction site practices provide greatest possible conservation of original soil What they replace: The bad old way: Mass grading Soil Compaction 19

20 ESD Planning Technique: Minimize Impervious Cover What it is: narrower streets, permeable driveways, clustered development, smaller cul-de-sacs, better pedestrian access, and other site design What it replaces: Super-sized lots, streets, sidewalks and cul-de-sacs 20

21 Planning Techniques: Minimize Site Impervious Cover * Can produce 10 to 30% reductions in impervious cover = lower stormwater runoff volumes * Comparative economics: Infrastructure cost savings of 10 to 40% have been reported when this technique is used * Maintenance and community acceptance: Less pavement means less maintenance. * Code change requirement: street design codes. Note 11 21

22 Northridge Open Section Roads, swales, attractive driveway culverts. Note woods next to lot. 22

23 Northridge Bowie, Prince George s County 40% of the site is preserved as open space, mostly woodlands. 23

24 Northridge Michael T. Rose Co. Disconnected downspouts 24

25 Northridge Sheet flow to open space: Disconnected downspouts drain to yards sloping to the woods. 25

26 Northridge ESD Elements A significant portion of the site s woodlands were preserved (40% open space)/ FCL maximization (not minimum compliance). Clustering of units. Open section roads draining to swales. swales include underdrains. Disconnected downspouts. Sheet flow of roof runoff to the woods. Standard BMPs: dry extended detention (ED) pond. 26

27 Auburn Village at Sandy Spring: Upper Northwest Branch, Anacostia Headwaters. (Winchester Homes) 27

28 Auburn Village At Sandy Spring ESD Elements 25 out of 50 acres preserved as buffer area, reducing clearing and grading costs. Clustering of units. Champion Tree preservation Historic spring head preservation. Some downspouts disconnected. Standard BMPs include: Sand filter/dry ED pond systems 28

29 The next generation of rain garden will be subtly graded into the street right of way and have a turf or landscape cover, depending on homeowner preference. Individual roof leaders A further runoff deduction at the front yard from the home and driveway drainage will hardwired into the dry swale Note 29 14

30 Pembroke: Emmitsburg, Frederick County Open Section Rds, Bioswales with Check Dams. 30

31 Pembroke Designer: Mike Clar; Builder: Ed Smariga Some of the streets include sidewalks sharing the right-of-way with Bioswales. Source: EcoSite, Inc. (Michael Clar, 2003) Pembroke Woods Low-Impact Development (LID) Residential Subdivision in Emmitsburg, Maryland. 31

32 Pembroke Front Yard Rain Gardens in some of the yards. 32

33 Pembroke Bioswales drain to a larger swale next to a preserved small woods. 33

34 Pembroke (Frederick County) ESD Elements Preservation of ~½ of site as wooded open space Open Section Roads with Bioswales bioswales contain 2.5 of engineered soil gravel bottom with underdrain Site fingerprinting w/ cluster design Elimination of 2 SWM ponds saved $200,000 Homeowner reports that standing water typically is gone within ~8 hours even for large storms Need for more education of realtors and buyers re: swales and overall ESD purpose 34

35 Redevelopment Site Design from Meliora Report (CBF, ANS, AWS 2008) Designers: Michele Adams and Altje Hoekstra Meliora Environmental Design, Philadelphia 35

36 Meliora Report Summary Table Comparison Between ESD and Conventional Stormwater LOT 31 Bethesda Redevelopment Project ESD Conventional DIFFERENCE $73,567 $132,684 -$59,117 36

37 Eastern Village CoHousing Silver Spring Vegetated courtyard used to be a parking lot. easternvillage.org 37

38 Eastern Village CoHousing Vegetated courtyard filters some runoff. Award-winning green roof. easternvillage.org 38

39 Maintenance Vactor Truck removing debris from underground stormwater vaults. Residential rain garden in Upper Sligo Creek designed by Jenny Reed. naturalresourcesdesign.com 39

40 Portland (OR) Green Streets: Redevelopment ESD features 40

41 ESD urban toolbox Photo: dcgreenworks.org; (Roof of Alexandria s library) Restoring natural area remnants Pollution prevention practices Compost-amended soils Impervious cover removal Permeable pavers Green roofs and cisterns Foundation planters Expanded tree pits Street bioretention Underground filters Stormwater retrofits Reforestation/restoration of stream corridor List: Tom Schueler chesapeakestormwater.net 41

42 III. ESD Plan Review Submitted by developers Review by local authorities Review and comment by local citizens In Montgomery County, review agency is the Department of Permitting Services, along with the Department of Planning and in some cases, the Department of Environmental Protection. 42

43 ESD Plan Review: Three Stages 1)Concept Plan 2) Site Plan 3) Final Erosion and Sediment Control Plan and Stormwater Management Plan 43

44 1) Concept Plan the proposed location of the limited disturbance, erodible soils, steep slopes and areas to be protected during construction; preliminary estimates of stormwater management requirements, the selection and location of ESD practices to be used and the location of all points of discharge from the site; 44

45 Concept Plan a narrative that supports the concept design and describes how ESD will be implemented to the maximum extent practicable; any other information required by the reviewing agency. The citizen s single best opportunity to influence the ESD site plan. 45

46 2. Site Development Plan concept plan information; final site layout Imperviousness information; proposed topography; drainage areas w/ points of discharge stormwater computations for ESD practices and quantity control structures; Erosion and Sediment control plan with phasing, Natural resource protection areas (set asides); ESD and other SWM features mapped 46

47 Site Development Plan a narrative that supports the site development design; describes how ESD will be used exhaustively to meet the minimum control requirements and justifies as being absolutely necessary any proposed conventional stormwater management measures; any other information required by the reviewing agency. 47

48 3) Final Erosion and Sediment Control Plan and Stormwater Management Plan This third submittal is the final erosion and sediment and erosion and stormwater management plans and must be of sufficient detail to allow all approvals and permits to be issued. The final plans are to be submitted in the form of construction drawings and accompanied by a report with sufficient information to evaluate the proposed runoff control and stormwater management design. 48

49 The final plan shall include Geotechnical investigations including soil maps, borings, site-specific recommendations and any additional information necessary for the final stormwater management design. 49

50 Drainage area maps depicting predevelopment and postdevelopment runoff flow path segmentation and land use. Hydrologic computations fo the applicable ESD and unified sizing criteria according to the Design Manual for all discharges from the site. 50

51 A narrative that supports the final stormwater management design and describes how ESD will be used exhaustively to meet the minimum control requirements and justifies as being absolutely necessary, any proposed standard stormwater management measures. 51

52 Also required in the final SW and ESC plan: Existing and proposed topography and proposed drainage areas, including areas necessary for proposed stormwater management facilities. Structural and nonstructural details including representative cross sections for all components of the proposed drainage system or systems and stormwater management facilities. 52

53 A table showing the ESD and unified sizing criteria volumes required in the Design Manual. An inspection and maintenance schedule. Any other information required by the reviewing agency. 53

54 IV Changes to the Regulations Note: These changes were approved by the Maryland General Assembly, and are subject to adoption by, and the case-by-case discretion of local governments. Grandfathering ESD Quantitative Stormwater Management Waivers. ESD Qualitative and Quantitative Stormwater Management Waivers Redevelopment Waivers 54

55 Grandfathering If a preliminary plan is approved by a local approval authority before May 4, 2010, the project may be allowed to escape ESD requirements. If a project is allowed to escape the new ESD requirements, they must fully comply with the older stormwater management requirements. 55

56 Grandfathering continued Grandfathering exemptions expire if: A project has not received final approval by May 4, 2013 A project has not been completed by May 4,

57 Waivers for In-Fill Development Projects The amended regulations provide that local governments may grant quantitative control waivers to in-fill development projects where the following are met: 1) The project is located in a Priority Funding Area (PFA); 2) The economic feasiblity of the planned project is tied to the planned density; 57

58 In-Fill Waivers continued. 3) The implementation of the 2009 ESD regulations would result in loss of the planned density; 4) Water and sewer and stormwater conveyance exist; 5) The quantitative waiver is applied to the project only for impervious cover that previously existed on the site. 58

59 In-Fill Waivers Continued ESD to the MEP is used to meet the full water quality treatment requirements for the entire site; ESD to the MEP is required to meet full quantity control for all new impervious surfaces on the site. 59

60 Waivers for Phased Development Projects Stormwater management quantitative and qualitative controls may be granted for phased development projects if: The project was designed to meet the 2000 regulations; It has been constructed by May 4, 2010; Where the project s future phases cannot meet the ESD regulations, all reasonable efforts to incorporate ESD in future phases must be demonstrated 60

61 Waivers for Redevelopment Projects Local approval authorities may develop separate policies for providing 'water quality' treatment for redevelopment projects, which may include: A combination of ESD and an on-site or off-site structural BMP; 61

62 Waivers for Redevelopment Projects Continued Off-site Retrofitting; Stream restoration projects; Pollution trading with another entity; Payment of a fee-in-lieu A partial waiver of the treatment requirements 62

63 Waivers for Redevelopment Projects Continued In deciding which alternative measures may be required, these factors may be considered: Whether the development is in an area targeted with development incentives such as a Priority Funding Area; a designated Transit Oriented Development area; or a designated Base Realignment and Closure Revitalization and Incentive Zone; Whether the project is necessary to accommodate growth consistent with comprehensive plans; Whether bonding and financing have already been secured based upon an approved development plan. 63

64 The End. QUESTIONS? 64