Restoring Water Balance
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Restoring Water Balance
- 1. Restoring Water Balance: From the Corner Lot to the Watershed Pallavi Kalia Mande, Charles River Watershed Association Jennifer Johnson, Nitsch Engineering, Inc. Cheeta Soga, Nitsch Engineering, Inc.
- 2. Restoring Water Balance: From the Corner Lot to the Watershed
- 3. Charles River Watershed Association Building Blue Cities: Environmentally Sensitive Urban Development Pallavi Kalia Mande Urban Restoration Specialist Charles River Watershed Association (www.charlesriver.org)
- 8. Impacts of Urbanization on Natural Water Cycle Charles River Watershed Association In Massachusetts, average annual runoff increases from 4.2” to 23” and groundwater recharge decreases from 21” to 6.3”.
- 9. CRWA’s Blue Cities Initiative Charles River Watershed Association Blue Development is a water-oriented approach to urban development and redevelopment that promote designs for the built environment that engages with every stage of the water cycle. Going beyond “green” building, “blue” development embraces green infrastructure design with the aim of restoring the natural water cycle in the built environment
- 12. Charles River Watershed Association Blue Cities Guide Available at: www.charlesriver.org/projects/docs/BlueCitiesGuide.pdf
- 17. Blue Cities Analysis Process and Design Approach Existing Conditions Analysis and Data Compilation Neighborhood Assessment and Survey Issues and Opportunities Analysis Concept Design and Visualization Recommendations for Green Infrastructure Retrofits Charles River Watershed Association
- 20. Bellingham Subwatershed Restoration Project Charles River Watershed Association Water Quality Management Planning Grant awarded by DEP to Town of Bellingham
- 21. Bellingham Subwatershed Restoration Project The Team:
- 22. Project Justification New Stormwater Regulations Water Quantity Water Quality Bellingham Subwatershed Restoration Project NPDES MS4 Permit EPA Designated Discharge Permit
- 23. 2011 NPDES MS4 Permit Source: EPA Website
- 24. 2011 NPDES MS4 Permit
- 37. 018B-Town Common Retrofit Before and after visualizations for proposed rain garden
- 39. Lesson Learned: Municipal Coordination Bellingham Subwatershed Restoration Project
- 41. Optimization Scenarios (BMP Type and Costs) Charles River Watershed Association $ 467,715 $ 264,750 $ 212,540
- 42. Peabody Square Pilot Demonstration Project
- 44. Peabody Square - Overview Dorchester Avenue Corridor Peabody Square
- 51. Peabody Square - BMP Evaluation Charles River Watershed Association
- 52. Peabody Square - BMP Evaluation Charles River Watershed Association
- 68. Restoring water balance requires collaboration at all scales, from the corner lot to the watershed.
- 69. Questions? Pallavi Kalia Mande, Charles River Watershed Association www.crwa.org Jennifer Johnson, Nitsch Engineering, Inc. Cheeta Soga, Nitsch Engineering, Inc. www.nitscheng.com
Hinweis der Redaktion
- Mission: use science, advocacy and the law to protect, preserve and enhance the Charles River and its watershed.
- Mission: use science, advocacy and the law to protect, preserve and enhance the Charles River and its watershed.
- Mission: use science, advocacy and the law to protect, preserve and enhance the Charles River and its watershed.
- Charles River Watershed Association (CRWA) has developed a suite of tools and an approach to the urban environment that will help create a new kind of place: a Blue City. Bringing together techniques such as Low Impact Development (LID), Green Buildings, Green Infrastructure, Green Corridors, and stormwater management with an eye toward recreating natural hydrology and treating rainwater like the resource it is. New England receives over 40 inches of rainfall a year on average. Properly managed, this water can cool buildings (directly and through strategically used vegetation), improve air quality, add aesthetic amenities, reduce flooding, and relieve drought. By restoring natural hydrologic function, Blue Cities initiatives can improve human and aquatic ecosystems. We can redesign our cities to capture and cleanse water and convey it to rivers, lakes, and harbors gradually through natural, vegetated channels. Blue Development incorporates designs for the built environment that engage with every stage of the water cycle. It identifies critical watershed problems, finds potential solutions, and brings people together to support restoration efforts.
- Discusses three case studies in which CRWA developed our Blue Cities Approach to urban planning and redevelopment. The three case studies are the neighborhoods of North Allston, Zakim North (Charlestown, Cambridge Somerville), Longwood Medical Area. Today I am going to go over the basic approach and then discuss one small piece of research and study that came out of the North Allston case study.
- The players: CRWA Nitsch Bellingham: Department of Public Works (directly responsible for MS4 compliance), Conservation, Planning, Funding from 604(b) grant via DEP
- Bellingham obtains water from groundwater – which feeds Charles River, low flow issues during summer and fall Water quality impairments – TMDLs for Charles River for pathogens and nutrients – requires phosphorus load reduction from Bellingham to Charles of 52% Portions of Charles listed as impaired
- Status of MS4 permits
- Similar to 2003 Program File NOI within 90 days of effective date of permit with EPA and DEP, Authorization issued by EPA after receipt of NOI Within 120 days of authorization municipalities need to develop and submit a Stormwater Management Program (SWMP) to EPA 3. llicit Discharge Detection and Elimination (IDDE) Program Develop mapping of entire MS4 system including catch basins, treatment structures, outfalls, receiving waters Delineate MS4 into catchments and include on mapping Comprehensive outfall inventory with specific descriptors 4. Construction Site Stormwater Runoff Control Program includes ordinance or regulatory mechanism to use erosion and sedimentation controls 5. Stormwater Management in New Development and Redevelopment New developments MA DEP Guidelines – Recharge and Water Quality regardless of location Assess current street and site design guidelines for possible changes to reduce impervious surface Track changes in impervious cover in community Inventory and rank municipal property that could be retrofitted with water quality, quantity, BMP’s 6. Good Housekeeping and Pollution Prevention O&M Plans for municipal properties and stormwater management system – catch basins, street sweeping, etc
- Phosphorus is the primary nutrient of concern in the Charles River and other TMDL-identified stormwater-impaired surface waters Why Phosphorus? Phosphorus is the primary nutrient in a river or lake that controls plant and algae growth. When there is too much phosphorus, it causes excessive growth of weeds and algae resulting in impaired water quality. This process is known as cultural eutrophication, which can cause major problems for aquatic life, restrict recreation, and threaten public health.
- Applies to existing and proposed sites Requires retrofits to existing properties Does not apply to single family homes or multi-family buildings with 4 units or less
- Bellingham – MS4 permit compliance – bylaws for illicit discharges, construction site stormwater runoff control, post-construction stormwater management at new developments, public outreach and good housekeeping – but not enough to resolve pollution issues
- Subwatershed Selection – identify appropriate subwatershed for restoration planning based on evaluation of existing environmental conditions, goal of 1-2 square miles Existing Conditions Assessment – Assess existing environmental conditions and hydrologic function, local water resources and infrastructure, and restoration objectives in the subwatershed, Use GIS/Town Data, verified with on-site observations Subwatershed Restoration Planning – Divide subwatershed into smaller drainage areas, identify on-site or regional treatment opportunities, preliminary engineering analysis and cost estimate Outreach and Education – Coordination with relevant town departments throughout the process, also 2 meetings to educate a broad spectrum of municipal officials and the public about the opportunities for restoration and the accompanying benefits
- Size variability Land use variability Variability in existing stormwater management (BMP present vs. no BMP present) Preference for areas draining to town owned land Preference for areas with a strong public education component (i.e. schools, recreational fields, etc.) DD Sites Stormwater management opportunities were also identified for the remaining sites, although conceptual designs were not developed for these sites.
- Developed a spreadsheet and hydrologic model to size BMPs based on EPA guidance documents Took it a step further to consider site constraints and other permitting requirements Correspondence with EPA – will allow 15% phosphorus removal for source control measures implemented by municipalities
- 7.6 acres – 80% impervious Commercial strip mall Steeply sloping parking lot Located within wetland buffer zone Designated discharge site under new EPA regs No existing stormwater BMPs BMP Selection: Bioretention basins for parking lot Infiltration trenches for roofs
- 7.6 acres – 80% impervious Commercial strip mall Steeply sloping parking lot Located within wetland buffer zone Designated discharge site under new EPA regs No existing stormwater BMPs BMP Selection: Bioretention basins for parking lot Infiltration trenches for roofs
- Conflict between reducing impervious area and zoning requirements Need buy-in from all departments Limited existing info- mapping, plans, etc, especially from older developments Enforcement coming down from Town to developers – how will it work? Phosphorus banks? New EPA regs- no much flexibility with BMP types
- Located in Dorchester, a neighborhood in the City of Boston – Boston’s most populous neighborhood Major north-south arterial spine Multi-legged, complex, high-accident-rate intersection Talbot Avenue (northwest to intersection) Dorchester Avenue (north-northeast to south-southwest) Ashmont Street (east-northeast to west-southwest)
- Urban design opportunity by enhancing neighborhood focus on square Create useable pedestrian environments with amenities Improve arrival to Square by creation of gateway Granite drinking trough to serve people and horses Civil clock installation (1909) Surrounding historic buildings (fire station, All Saints Episcopal Church, Peabody Apartments, O’Brien’s Market)
- St. Mark’s Area Main Street Group – St. Mark’s Area Main Street Vision completed in June 2004 (included comprehensive community process and evaluation)
- City of Boston Environment Department received grant funding for a Green Street Pilot Demonstration Project Dorchester’s historic Peabody Square selected because the project already had active community partners and a knowledgeable project team with a deep sustainability mindset BMP selection important because the study area drains to the Neponset River, which is on the Massachusetts list of imparied waters and is identified as impaired for organics, pathogens and turbidity, all common pollutants in stormwater runoff City is trying to commission an informational plaque
- - Developed 5 intersection redesign alternatives and evaluated several sustainable options suitable for this busy, urban neighborhood crossroads
- Selected a design that: eliminated the channelizing islands discontinued one street leg realigned Talbot Avenue reduced neighborhood cut-through traffic decreased traffic queuing (and thus reduced air pollution) created a socially inviting park and plaza
- With the lack of green spaces and street trees in the area, a need for replacing paved areas with vegetative and soil based best management practices was immediately identified
- To reduce runoff volume and remove pollutants, considered several structural and management BMPs: Stormwater planters Porous concrete/asphalt pavements Leaching basins Greening Open-joint paving Bioretention (rain gardens) Evaluated their benefits relative to stormwater management goals, site-specific constraints, and capital/maintenance costs
- CRWA has since developed fact sheets for each of these BMPs Fact sheets are available on their website
- Runoff from Dorchester Avenue directed to the rain garden Excess runoff overflows into a raised grated structure and directed to the City’s storm drain system in Ashmont Street
- Other benefits include: Runoff temperature reduction Provides wildlife habitat
- Stone trench/diaphragm provides pretreatment (allows sediments carried in first-flush runoff to settle out) Other benefits include: Runoff temperature reduction Provides cost-effective way of managing stormwater
- Other benefits include: Runoff temperature reduction Flexibility for use in areas with irregular shapes/sizes