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Created and developed to meet the needs of industry, Lower Mill Pond in Easthampton, Massachusetts, and its nearby neighborhoods have changed as the economy has shifted. Today, places rendered derelict and obsolete by a decline in manufacturing are being re-visioned, re-purposed, and re-integrated into the cultural and economic landscape.

A Neighborhood Strategy for Improving the Lower Mill Pond Watershed Easthampton, Massachusetts

Today, non-point source pollution and stormwater runoff are the major threats to the pond. Implementation of best management practices will require not only an understanding of site-speciďŹ c conditions, but also a programmatic framework that promotes solutions at all scales. Vacant property could be acquired, protected, and restored as naturally vegetated green space for passive recreation. New and redevelopment projects requiring zoning review and permits are opportunities to work collaboratively with project proponents to include green infrastructure elements that capture and treat stormwater on site and add trees and other plants to the neighborhood. Municipal properties and the street right-of-way may present the most readily accessible locations for implementing green infrastructure, planting street trees, and educating the public through demonstration sites.

The Conway School is the only institution of its kind in North America. Its focus is sustainable landscape planning and design and its graduates are awarded a Master of Science in Ecological Design degree. Each year, through its accredited, ten-month graduate program students from diverse backgrounds are immersed in a range of real-world design projects, ranging from sites to cities to regions. Graduates play signiďŹ cant professional roles in various aspects of landscape planning and design. Fix what’s broken. Save what works. Design the future!

Prepared for the City of Easthampton The Conway School - Winter 2015


A Neighborhood Strategy for Improving the Lower Mill Pond Watershed Prepared for Jim Gracia, City Engineer and Jessica Allan, City Planner Easthampton, Massachusetts

Ben Fairbank, Alex Krofta, Janice Schmidt The Conway School • Winter 2015


Acknowledgements The Lower Mill Pond Team would like to thank Jim Gracia from the Easthampton Department of Public Works, Jessica Allan from the Easthampton Planning Department, and Matthew Reardon from the Massachusetts Department of Environmental Protection.


Contents Executive Summary ................................................................................................................. 1 Context: A History of Change ................................................................................................. 2 Context: Nature as a Partner .................................................................................................. 4 Context: Water Quality in Lower Mill Pond ........................................................................... 8 Context: Down the Storm Drain and into the Pond ................................................................ 9 Analysis: Identifying the Opportunities for Improvement ..................................................... 12 Analysis: Green Spaces: For Water, Wildlife, and People .....................................................16 Analysis: Restoring Infiltration: Conditions Underground ................................................... 18 Analysis: Intercepting Stormwater: Conditions Above Ground ............................................ 20 Solutions: A Framework for Taking Action ........................................................................... 22 Solutions: Site Prototypes ..................................................................................................... 26 Solutions: Case Study: SEA Streets, Seattle, WA .................................................................. 38 Solutions: Additional Resources ........................................................................................... 39 Data Sources for Maps .......................................................................................................... 40 References .............................................................................................................................. 44


Executive Summary The City of Easthampton commissioned the Conway School to conduct a study of the Lower Mill Pond watershed and provide recommendations for managing the city’s stormwater in this area. This report presents a strategy for improving both the health of Lower Mill Pond and the neighborhood surrounding it. Lower Mill Pond has great significance for Easthampton. Created in 1859 to power mill factories, it was home to technological advancements that led to industrial and economic growth. Jobs were created and a quiet agricultural community transformed into a booming industrial town. With rapid development came industrial activities that placed the ecological health of the pond at risk. Even though these activities ceased several decades ago, both regulators and community members are concerned about the health of Lower Mill Pond. Today, non-point source pollution and stormwater runoff are the major threats to the pond. This plan recommends ways to manage the pond’s watershed to comply with federal regulations and to restore it as a viable recreational and ecological resource. This report presents strategies to: • Improve water quality of Lower Mill Pond in order to comply with federal requirements under the National Pollution Discharge Elimination System (NPDES) requirements, enhance recreational opportunities in and around the pond, and improve ecological functions. • Increase green space and green infrastructure in the densely developed neighborhoods surrounding Lower Mill Pond for quality of life improvements and stormwater benefits. The watershed is divided into four catchment area categories defined by their relationship to the municipal storm sewer and to the pond. Within each catchment area, the acreage of directly connected impervious area (DCIA) is calculated. These calculations help to identify those areas potentially contributing greater volumes of stormwater runoff to the storm sewer and pond. An evaluation of soils and depth to groundwater within the watershed identified four types of infiltration capacity: good, variable, medium, and low. A site’s capacity for infiltrating stormwater will be a major consideration in the selection of green or gray infrastructure systems. Of the 1,200 parcels within the watershed, 1,000 are residential properties. Outreach to and technical support in this sector will be important to reduce the volume of runoff and pollutants entering Lower Mill Pond. Implementation of best management practices will require not only an understanding of site-specific conditions, but also a programmatic framework that promotes solutions at all scales. Vacant property could be acquired, protected, and restored as naturally vegetated green space for passive recreation. New and redevelopment projects requiring zoning review and permits are opportunities to work collaboratively with project proponents to include green infrastructure elements that capture and treat stormwater on site and add trees and other plants to the neighborhood. Municipal properties and the street right-of-way may present the most readily accessible locations for implementing green infrastructure, planting street trees, and educating the public through demonstration sites.

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A History of Change In a mill town neighborhood shaped by its industrial past, a restored mill pond can be the centerpiece of community revitalization.

WHY IT MATTERS The Lower Mill Pond neighborhood is a dynamic landscape that has continuously changed since its creation just over 150 years ago. To imagine and implement a new vision for its future, one that includes a healthy Lower Mill Pond, it is important to understand the area’s history and the factors that have driven change. FINDINGS Created and developed to meet the needs of industry, the pond and nearby neighborhoods have changed as the economy has shifted. Today, places rendered derelict and obsolete by a decline in manufacturing are being re-visioned, re-purposed, and re-integrated into the cultural and economic landscape. IMPLICATIONS Just as it played a pivotal role in Easthampton’s past, Lower Mill Pond and its surrounding neighborhoods can be a central component of its future. THINGS TO KNOW

Pleasant Street. Lower Mill Pond was mainly used as a dump for mill waste.

An Industrial Community

During the Industrial Revolution, as business increased, more factories were built and workers from England, Germany, Ireland, Poland, and Canada arrived. Housing was built for the mill workers and their families in the New City and Everett Street villages and connected to the mills by bridges over the pond.

As early as the late 1600s, mills were being built in Easthampton along the Manhan River. By the mid-1800s mills were also being built on other streams and brooks in Easthampton. In 1847, Samuel Williston dammed Broad Brook to make Upper Mill Pond, now called Nashawannuck, for power to run his new factory. Lower Mill Pond was formed twelve years later, in 1859, when Broad Brook was dammed again to power mills built on

Early in the 1900s, Williston sold the mills to the West Boylston Manufacturing Company, which operated there until about 1932 when it ceased operation and the

Pleasant Street Mills Footbridge Now-buried stream

New City Neighborhood

A map from 1873 shows the landscape in transition. The New City neighborhood was developing, connected to the mills on Pleasant Street by a footbridge across Lower Mill Pond. A wide swath of open land still existed to the south of the pond. A small stream, now buried and lined with sewer pipes, flowed into the pond near Everett Street. (Courtesy of Forbes Library)

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A Neighborhood Strategy for Improving the Lower Mill Pond Watershed

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buildings were subdivided and sold. By the 1960s, factories started downsizing or closing due to increasing global competition. By the end of the twentieth century many of the mills sat empty.

Transformed and Revitalized

Several of the mill buildings have found new life and are being revitalized as mixed-use buildings. Apartments, retail space, offices, light industry, artist studios, and galleries are some of the common uses. The old railroad

has been converted to a rail trail and connects to a regional bike network through Northampton. Millside Park on the north side of the pond has been rebuilt and two more spaces to the west, with trails and parks, are scheduled to be built in 2015-2016. Property values in New City and Everett/Franklin Street neighborhoods have risen, coinciding with the mill revitalization and other commercial and artistic enterprises in the blossoming creative economy.

An artist’s rendering of planned and completed renovations to the Pleasant Street mill complex and Lower Mill Pond Park. The rail trail paralleling the mills and the circular park and bandshell in the bottom right are existing. The parking lots and additional green space along the pond are slated for construction. (Courtesy of City of Easthampton) The Nashawannuck Pond Restoration Nashawannuck Pond (formerly Upper Mill Pond) is a valuable economic, recreational, and environmental resource for Easthampton. Though constructed to power industry, it was not as highly developed or polluted as Lower Mill Pond. It has since become a focal point for fishing, boating, and recreation. Still, the Nashawannuck Pond Watershed Restoration Project report prepared by Pioneer Valley Planning Commission and Nashawannuck Pond Restoration Project Advisory Committee concluded that Nashawannuck Pond has been greatly affected by eutrophication and heavy nutrient and sediment loading. In response, the Pioneer Valley Planning Commission, the City of Easthampton and the Nashawannuck Pond Steering Committee have worked together to undertake restoration of Nashawannuck Pond. They: •

Dredged to increase water depth and to remove polluted sediments.

Updated the storm sewer system with deep sump catch basins.

Removed aquatic invasive species and stabilized slopes.

Conducted outreach to promote “urban housekeeping.”

The City of Easthampton can take advantage of resources and a planning structure already in place from the Nashawannuck Pond Restoration to organize efforts for Lower Mill Pond.

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Nature as a Partner A diversity of plants, animals, and ecological processes have persisted in this highly urbanized watershed and will play an important role in the city’s future.

WHY IT MATTERS As Easthampton and other New England cities and towns industrialized, natural habitat was lost, key ecological processes were disrupted, and wastes were sometimes dumped indiscriminately. Yet, natural features still exist in many of these places, in various levels of health. FINDINGS Conditions upstream of Lower Mill Pond affect its ecological quality, and the pond in turn affects habitat downstream. Thought to be environmentally degraded due to past pollution and alteration of the watershed, Lower Mill Pond and its environs do provide a degree of habitat value, connectivity between protected areas, and ecosystem services, especially when compared to the highly developed surrounding landscape. IMPLICATIONS Preserving and enhancing the ecological functions of the existing natural features could be the basis for creating greener, more ecologically vibrant neighborhoods by planning based on a watershed perspective, understanding the roles of wetlands, and enhancing landscape connections. THINGS TO KNOW

A Healthy Watershed Matters

The health of a water body is directly related to the condition of its watershed. A watershed is the area of land that drains to a common point. The common point is generally a body of water or the terminus of a stream, but a watershed can be defined for any point. Watersheds are nested within one another. A watershed consists of innumerable smaller watersheds, and is itself part of another larger watershed. Lower Mill Pond is within the Connecticut River basin, a large watershed extending from Long Island Sound to Canada. This large watershed is divided into numerous smaller watersheds called sub-basins. Lower Mill Pond lies near the terminus of the “CT6184” sub-basin. The sub-basin can be divided even further into Watersheds are nested within one another. The Lower Mill Pond smaller watersheds, called sub-watersheds, sub-watershed is nested within the CT6184 sub-basin. The CT6184 based on drainage to particular water bodies. The Lower Mill Pond sub-watershed, which is sub-basin is one of many sub-basins which make up the Connecticut all the land area that drains to the pond, is the River watershed. focus of this project. Nashawannuck Pond upstream and its sub-watershed are excluded, even though flow from Nashawannuck affects water quality in Lower Mill Pond. Nashawannuck Pond and its subwatershed are already the focus of ongoing restoration efforts that include water quality improvement measures.

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The Value of Wetlands

The wetland areas pertaining to this project are Lower Mill Pond, which covers approximately thirty acres; swamps occurring along Plum and Brickyard Brooks and near the inflow from Nashawannuck Pond; and the marsh at the storm sewer outfall at the northwest corner of Everett Street. Steep-walled concrete channels form the inlet connection with Nashawannuck Pond and the outlet of Lower Mill Pond. The bordering vegetated wetlands along the pond provide diversity due to their variable physical structure, flow rates, and biological communities. Because of this, they provide some capacity to mitigate the negative impacts of stormwater. They can slow and absorb runoff

volumes, uptake excessive nutrients in vegetation, and break down other pollutants through biological processes.

The Landscape Makes it Possible

Though degraded, Lower Mill Pond is still home to waterfowl, fish, and other aquatic organisms. Its wooded shoreline provides habitat and movement corridors for birds, mammals, and other species. Many connections exist and interactions occur between the pond and the surrounding waterways and forests. The ecological health and function of the pond is important for species and processes both within its banks and in the landscape beyond. Water, sediment, pollutants, and aquatic organisms flow from Nashawannuck Pond over the Cottage Street dam and into the pond from the west. Due to the steep concrete structure of the dam and the channelized stream, there is likely little, if any, aquatic ecological connection upstream from Lower Mill Pond into Nashawannuck Pond. A strip of forest west of Adams Street is the only natural corridor partially extending into the maze of parking lots, busy roads, commercial buildings, and mills along Cottage Street.

In addition to Lower Mill Pond, the sub-watershed contains marshes, swamps, and streams. It also contains dams and a highly altered concrete stream channel.

Plum and Brickyard Brooks flow north through a series of wetlands and culverts and into Lower Mill Pond on its southern shoreline. Water, with possible sediment and pollutants, and aquatic organisms enter the pond here. Though movement of aquatic organisms from the pond and into the stream is hampered by the culverts, terrestrial species may make use of the vegetated riparian corridor for travel up and downstream along the pond. Road crossings at Everett, Clark, and East Streets create a barrier to some species. East of East Street is BioMap2 Core Habitat and CAPS High Value Refugia (“Ecological Integrity and Habitats Map� p. 6) in the forests of Mount Tom State Reservation.

Water flows out of Lower Mill Pond over the Ferry Street dam and into a cement channel between the Ferry Street mills. From this point, a meandering stream flows into BioMap2 Core Habitat and Aquatic Core Habitat along the Manhan River and into the Connecticut River Oxbow. The Ferry Street dam

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Lower Mill Pond is highly degraded but provides a degree of habitat connectivity, in an otherwise developed landscape, between rare species habitat to the north and east. The outflow from the pond directly affects water quality in rare species habitat downstream in the Manhan and Connecticut Rivers.

prevents upstream movement of aquatic species, but some overland movement may be possible along the Manhan Rail Trail, around the mills, and across Ferry Street. Because of its location, Lower Mill Pond, its wetlands, and forest habitats form connections, including: • a two-way link between habitat at the Manhan and Connecticut Rivers to the north and east and habitat at the Mount Tom State Reservation to the south.

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• a one-way hydrologic connection from the entire CT6184 sub-basin to downstream water bodies. Future efforts should seek to improve water quality in the pond by increasing natural features and open green space within the surrounding neighborhood. Such an approach will benefit the pond and its inhabitants, the human residents of the neighborhood, as well as the wild species and ecological processes across the broader landscape.

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Conservation Assessment and Prioritization System (CAPS), UMass Amherst “The Conservation Assessment and Prioritization System (C.A.P.S.) is an ecosystem-based (coarse-filter) approach for assessing the ecological integrity of lands and waters... Ecological integrity is the ability of an area to support biodiversity and the ecosystem processes necessary to sustain biodiversity over the long term. CAPS combines principles of landscape ecology and conservation biology with the capacity of modern computers to compile spatial data and characterize landscape patterns. This process results in a final Index of Ecological Integrity (IEI) for each point in the landscape based on models constructed separately for each ecological community.” From: Department of Environmental Conservation, UMass Amherst. www.umasscaps.org

BioMap2 - Massachusetts Natural Heritage and Endangered Species Program “BioMap2 is designed to guide strategic biodiversity conservation in Massachusetts over the next decade by focusing land protection and stewardship on the areas that are most critical for ensuring the long-term persistence of rare and other native species and their habitats, exemplary natural communities, and a diversity of ecosystems. BioMap2 is also designed to include the habitats and species of conservation concern identified in the State Wildlife Action Plan.” From: Massachusetts NHESP. www.mass.gov

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Water Quality in Lower Mill Pond The level of contamination today is now considered suitable for some recreational use, though questions remain.

WHY IT MATTERS Understanding past practices and current pollution problems will help set realistic goals for future use and identify opportunities for improvement. FINDINGS Though pollution of the pond was extensive in the past, there is no conclusive data regarding existing contaminants, their quantity, or their toxicity. Nor is there any immediate plan to gather this data. For the foreseeable future, recreational use of the pond will continue to include fishing (catch and release) and boating. The best-known current threat is polluted stormwater discharges from the surrounding neighborhoods. IMPLICATIONS Reducing the harmful effects of stormwater that flows into the pond is the issue of highest priority in order to meet federal regulatory requirements and to improve the recreational and ecological values of Lower Mill Pond. THINGS TO KNOW

A History of Contamination

Longtime Easthampton residents share stories of a pond so polluted that it changed colors from day to day, could catch fire from a tossed cigarette, and emitted enough chemical odors to be dubbed “Perfume Pond.” During the late nineteenth and early twentieth century, industrial wastes were dumped into Lower Mill Pond. Because of the pond’s proximity to the mills and an absence of environmental regulations, textile, button and battery manufacturers dumped dyes, kerosene, and petroleum-based products. Specific pollutants and quantities are unknown.

Clean Water Act: Past and Present

In 1972, the Clean Water Act was passed and a new era of environmental awareness began. Though much of the industrial activity in the mills around Lower Mill Pond had already ceased for economic reasons, there were now laws in place against the type of abuses that had occurred in the past. Specifically, the National Pollution Discharge Elimination System (NPDES) permitting process administered by the U.S. Environmental Protection Agency (EPA) began to regulate point-source discharges to surface waters. This has made point-source discharges of waste largely a thing of the past, and now the EPA is also targeting nonpoint-source discharges. Municipal storm sewer systems are increasingly the focus of the NPDES permitting process in an effort to further improve water quality in U.S. waterways. Easthampton is regulated under a Municipal Separate Storm Sewer System (MS4) permit.

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Available Water Quality Data MA Department of Environmental Protection The “Connecticut River Watershed 2003 Water Quality Assessment Report” labels Lower Mill Pond as “Category 2- Attaining Some Uses (Secondary Contact Recreation and Aesthetics),” with other uses not assessed. Also described in this document is a 2002 DEP study that showed levels of mercury, arsenic, lead, cadmium, selenium, and other pollutants in fish to be below toxicity thresholds. Fish consumption, however, is officially “not assessed.” Aquatic life is “impaired” due to the invasive water chestnut (Trapa natans). Outfall Testing by Easthampton DPW City Engineer Jim Gracia conducted city-wide dry-flow outfall tests in 2002 and identified a number of illicit sanitary sewer connections contributing nitrogen pollution to the stormwater system. Such connections are common in older industrial cities, and the Department of Public Works has been source-tracking and eliminating them. Nashawannuck Pond The Nashawannuck Pond Watershed Restoration Project report cited the “Diagnostic/Feasibility Study for the Management of Nashawannuck Pond” (prepared in 1988 by Baystate Environmental Consultants, Inc.) which identified nitrogen and phosphorous loading in Nashawannuck Pond. This is a likely indicator of conditions in Lower Mill Pond, given that the ponds’ sub-watersheds are similar and they are connected at the Cottage Street dam.

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Down the Storm Drain and into the Pond Neighborhood storm sewers are discharging minimally treated runoff directly into the pond.

WHY IT MATTERS Because of pollution loads and disrupted hydrologic function, stormwater discharges are the primary known threat to water quality in Lower Mill Pond and other waterways in the area. FINDINGS In urban watersheds, hydrologic processes are drastically altered. Trees and plants are replaced by hard surfaces of rooftops and roadways, and stormwater isn’t able to infiltrate into the groundwater and is diverted by sewer pipes to discharge into water bodies. Pollution swept into storm drains is discharged into water bodies as well, threatening water quality. IMPLICATIONS Improving water quality in Lower Mill Pond begins with restoring, to the extent possible, natural hydrologic functions within the sub-watershed. This means reducing pollution, reducing and disconnecting paved areas from each other, and creating more open space and green features in the surrounding neighborhood. THINGS TO KNOW

How Stormwater Becomes Polluted

Storm sewer systems are designed to move precipitation (rainfall and snowmelt) away from the built environment. Typically the built environment accumulates more stormwater on the land’s surface than a naturally vegetated landscape, because it is dominated by impervious cover in the form of rooftops, pavement, and compacted soil, which prevent the natural infiltration of precipitation into the groundwater. The accumulated precipitation flowing across the surface of the land is collected in storm drains along the streets and carried in underground pipes to an outfall, which then typically discharges to a water body.

As stormwater flows across the urban landscape, it washes pollutants into the storm sewer system and then into water bodies. Different pollutants come from different sources, and the concentrations tend to vary by land use. Storm sewer infrastructure has some capacity to treat stormwater as it flows though the system. Catch basins (known as storm drains) along the street can be designed to capture large sediment particles, trash, and oil. A finishing filter, located near the outfall to a water body, is designed to remove finer sediments, additional grease and oil, and other pollutants. The sewer system discharging to Lower Mill Pond consists of older, shallow catch basins and lacks finishing filters, providing minimal filtration.

Precipitation falls onto impervious surfaces and runs off as stormwater. It is collected in catch basins, transported away from the built environment through storm sewer pipes, and then discharged into a waterbody from an outfall pipe.

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Directly Connected Impervious Area (DCIA) in the Lower Mill Pond Watershed According to the EPA (Small MS4 Permit Technical Support Document, Revised April 2014), watersheds are negatively affected when total impervious area reaches 4 to 6% and severely affected over 12%. According to the US EPA CADDIS Urbanization Module, research shows that the percentage of Directly Connected or Effective Impervious Area is an even stronger indicator of watershed degradation.

The percent DCIA for the entire CT6184 subbasin is 7.8%, indicating degraded health of the watershed. The percentage DCIA for the Nashawannuck Pond sub-basin is 5%, and DCIA for the Lower Mill Pond sub-watershed is 16.8%, indicating it is severely affected.

The Role of Impervious Surfaces More impervious area in a watershed leads to less infiltration and more runoff. When impervious areas are connected to one another by contiguous pavement, rooftop drains, and storm sewer pipes, the amount of polluted stormwater discharged to waterbodies can increase greatly. The amount of directly connected impervious area (DCIA) is therefore an important indicator of watershed health.

The urbanized landscape decreases groundwater infiltration and evapotranspiration, and increases surface runoff. Source: US EPA

Stormwater and Hydrology

A heavily altered watershed often leads to lower yearround water levels (base-flow) in urban streams and ponds, and higher flood levels during storm events. This

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rapid, “flashy� pattern of fluctuation occurs because impervious surfaces and storm sewers divert precipitation away from slow, constant groundwater recharge and channel it directly to surface waters.

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Common Pollutants in Stormwater Adapted from: Central New York Stormwater Coalition

Pathogens Bacteria and viruses in pet waste can sicken wildlife, as well as humans recreating at the pond.

Nutrients Fertilizers promote algae growth which can clog the pond, block sunlight, and deplete oxygen.

Sediments Road sand and other particles can smother vegetation and underwater habitat for many species.

Toxins Gas, oils, pesticides, auto fluids, road salt, and soaps may be toxic to wildlife, even in small amounts.

Temperature Surface stormwater exposed to sun is warmer than naturally flowing groundwater, affecting aquatic species.

Floatables Unsightly litter reduces recreational values of the pond, and trash can sometimes kill wildlife.

Organic Waste Grass clippings and other debris consume oxygen in water as they decompose, threatening pond life.

Stormwater Pollutants and Land Use The pollutants that are swept up in stormwater and discharged to waterbodies vary in concentration depending on land use. If water quality tests indicate elevated levels of a particular pollutant, this table can help to identify specific land uses or individual sites within the watershed that may be contributing. Similarly, different stormwater Best Management Practices (BMPs) reduce different pollutants. This information can be used to determine what type of BMP may be most appropriate for a particular site based on its potential pollutant contributions. Source: Austin, 2014. Green Infrastructure for Landscape Planning

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Identifying Opportunities for Improvement Some parts of the sub-watershed harbor greater threats to water quality than others.

WHY IT MATTERS Understanding which catchments pose the greatest threat to Lower Mill Pond’s water quality allows planners to direct efforts most effectively. FINDINGS Catchments pose different threat levels depending on whether stormwater is discharged directly into the pond (called Category A catchments in this report) or into wetlands with filtering capacity (Category B catchments). Within each category, the amount of directly connected impervious area (DCIA) determines the threat posed by each catchment. Category C and D catchments are not connected to the storm sewer system, though they both may have effects on the water quality of the pond; further investigation is required to quantify these effects. IMPLICATIONS There are limited municipal resources to implement improvements. Analysis of where catchments discharge and of percentage of DCIA can be used to develop broad guidelines for setting priorities for improving water quality. More detailed site analysis, however, will be needed to identify where specific opportunities for mitigation exist. Additionally, the goals of neighborhood improvement and ecological benefits should be incorporated into deciding where and how to focus efforts. THINGS TO KNOW

Defining Catchments

The sub-watershed is made up of nested catchments or drainage areas. The shape and extent of each catchment area is determined not just by topography (as in an undisturbed landscape), but by drainage through the storm sewer system. A storm sewer map provided by Easthampton DPW was used to define which areas drain to a particular outfall location. Easthampton Water Department personnel reviewed the resulting catchment drainage map.

Catchment Prioritization #1: Drainage Configuration

Once defined and mapped, catchments are prioritized based on their connection to the storm sewer system and the outfall location. Catchments in Category A are connected to the storm sewer system and discharge stormwater from an outfall pipe into Lower Mill Pond. Because this is the most direct input of untreated stormwater to the pond, these catchments are considered (in this report) to be primary threats to water quality. Catchments in Category B are connected to the storm sewer system which then discharges stormwater from an outfall pipe into the wetland complex surrounding Plum and Brickyard Brooks. Since these wetlands have an opportunity to capture sediments and filter pollutants

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from stormwater before it flows into the pond, these catchments are considered (in this report) to be secondary threats to water quality in Lower Mill Pond. Stormwater discharges to these wetlands are still, however, of significant concern. First of all, these wetlands provide habitat and ecosystem functions and should therefore be treated as valuable resources in their own right. Secondly, their capacity to treat stormwater before it flows into Lower Mill Pond has not been quantified. Further analysis beyond the scope of this report is needed to evaluate the impact of stormwater on these wetlands as well as the impact of the wetlands on stormwater quality. Catchments in Category C are not connected to the storm sewer system. Since the focus of this report is Easthampton’s stormwater system, these areas are not comprehensively addressed here. Land use within these catchments includes forests, wetlands, agriculture, residential areas, and cemeteries. Additionally, it is assumed that most of the areas have a relatively undisturbed hydrologic regime, with most precipitation soaking into the ground and infiltrating groundwater. Future analysis, however, should test these assumptions. Catchments in Category D are dominated by mill buildings and are also not comprehensively addressed here. These areas are primarily made up of impervious rooftops and parking lots. They are not connected to the storm sewer system, but contribute stormwater directly to Lower Mill Pond from sheet-flow off parking lots and

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Catchment areas were delineated according to the location of storm sewer pipes and outfalls. All of the land area within a catchment discharges to a single outfall.

through roof drains that collect and discharge runoff to the pond from outfall pipes. Recent and ongoing renovations at One Cottage Street and the Pleasant Street mill complex are incorporating stormwater management measures into their landscapes, mitigating their negative impact on water quality. These catchments will need to be analyzed in further detail on a site-by-site basis. Older mills that are not being renovated may be a priority due to their potentially antiquated drainage systems.

Catchment Prioritization #2: Directly Connected Impervious Area

Once prioritized based on their outfall location, Category A and Category B catchments were prioritized according to their amount of Directly Connected Impervious Area (DCIA). The percentage of DCIA and total acreage of DCIA was determined for each catchment using a methodology developed by the US EPA. For this project, the catchments with the highest total DCIA acreage are

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considered to be the greatest threat within each catchment category. Though percentage of DCIA in each catchment is a good descriptive measure of conditions within the catchments, the total acreage of DCIA is a more important determinant of the volume of stormwater discharged from a particular outfall.

Calculating Directly Connected Impervious Area A Geographic Information System (GIS) based computer program was used to determine the amount of Directly Connected Impervious Area within the sub-basin, the sub-watershed, and the catchments. The program, which was developed and provided by Matthew Reardon at Mass DEP, is an automated version of the one detailed in “EPA’s Methodology to Calculate Baseline Estimates of Impervious Area (IA) and Directly Connected Impervious Area (DCIA) for Massachusetts Communities” (2010). The EPA’s methodology uses the Mass GIS datalayer of Impervious Cover to calculate the amount of Impervious Area (IA) within a delineated watershed. Then, using the MassGIS Land Use datalayer, it calculates the amount of DCIA in each section of IA according to Sutherland’s equations for estimating DCIA per land use type (Sutherland, R.C., “Methodology for Estimating the Effective Impervious Area of Urban Watersheds”). The methodology described here provides an estimate, and is more appropriate for larger watersheds. Though catchment-level analysis may be too-fine a scale to accurately predict DCIA, use of the model is helpful as a method to compare the relative impact of the different catchments within a sub-watershed (M. Reardon, personal communication).

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Priority A: catchments with Priority B: catchments with discharge to pond discharge to wetlands Catchment

Acres of DCIA

Catchment

Acres of DCIA

A1

32.5

B1

7-8

A2

20.5

B2

5-7

A3

12.5

B3

4-5

A4

10-11

B4

3-4

A5

7-9

B5

<2

Category A catchments present the greatest threat to Lower Mill Pond water quality. Category B catchments present the second greatest threat. Within these categories, the catchments are prioritized 1 to 5 based on their acreage of directly connected impervious area. Category C and D catchments are not connected to the storm sewer system.

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Green Spaces: For Water, Wildlife, and People Green space and natural features are needed in the neighborhood, for stormwater infiltration, for species habitat and connectivity, and for human enjoyment.

WHY IT MATTERS In addition to mitigating the water quality impacts of stormwater, urban green space also provides habitat, recreational opportunities, and other quality-of-life benefits. FINDINGS Areas lacking accessible green space in Easthampton coincide with areas posing the greatest threat to water quality. A desire for more green features and accessible open space has been expressed in the Lower Mill Pond neighborhood. A map of land use shows wide swaths of commercial, residential, and industrial areas. The few strips of green that remain are mostly inaccessible for recreation, especially south of the pond. The lack of green space affects a third of Easthamptonâ&#x20AC;&#x2122;s population and falls disproportionately on its lower-income residents. IMPLICATIONS The Lower Mill Pond neighborhood provides an opportunity to address both problems simultaneously, with improvements that infiltrate stormwater and add green space.

THINGS TO KNOW

Land Use and Green Space Map

An examination of land use and accessible green space shows a highly developed commercial, industrial, and residential neighborhood surrounding Lower Mill Pond. Vegetated areas are concentrated in a narrow strip around the pond itself and along Plum and Brickyard Brooks. Only a few of these green spaces are open or easily accessed for public recreation; most are vacant private property or cemeteries. The 2013 Easthampton OSRP established a goal of providing recreational open space within one half mile of all residents. Brickyard Brook Conservation Area is accessible, but mainly to residents in the southern section of the subwatershed. Lower Mill Pond Park and the Manhan Rail Trail are 1.3 and .75 miles average walking distance from the New City neighborhood. The Everett Street neighborhood has few outdoor recreational opportunities; the Maple Street School playground is one option. While accessible from a trail head near East Street, Mount Tom State Reservation is beyond the halfmile walking distance threshold for most residents (Easthampton OSRP 2013).

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Environmental Justice Areas (2010 Census) Environmental Justice Areas identify U.S. Census Block Groups with minority, low income, and non-English speaking populations. Much of the Lower Mill Pond neighborhood is in the low income category, with median household income at or below $40,673. (Adapted from MassGIS.)

A Neighborhood Strategy for Improving the Lower Mill Pond Watershed

ANALYSIS


Very little recreational green space is available in the dense residential, commercial, and industrial landscape surrounding Lower Mill Pond.

Urban Tree Canopy

Easthampton recognizes the value of street trees and shade trees for their ecological and quality-of-life benefits. Though there is no current inventory of urban trees in the city, there are few trees in the dense urban neighborhoods of Lower Mill Pond.

A Neighborhood Strategy for Improving the Lower Mill Pond Watershed

ANALYSIS

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Restoring Infiltration: Conditions Underground Existing soils and depth to groundwater within the Lower Mill Pond sub-watershed create four types of stormwater infiltration capacity.

WHY IT MATTERS Restoring the natural flow of rainwater and snowmelt into the ground is the primary approach to mitigating stormwater’s impact on water quality, and to reducing pollutants entering waterbodies. FINDINGS Natural infiltration depends on the soil’s drainage characteristics and the depth to groundwater. Good infiltration capacity occurs in the Everett Street neighborhood, along Cottage Street, and near Union Street north of the Manhan Rail Trail. The New City neighborhood, areas east of Plum and Brickyard Brooks, a strip following the rail trail, and scattered other locations have variable infiltration capacity. The lowest infiltration capacity underlies wetlands. IMPLICATIONS A poorly designed or poorly sited mitigation feature will benefit neither water quality nor quality-of-life. Locations within the sub-watershed with suitable conditions should focus on infiltrating stormwater into the ground. Locations with less infiltration capacity may need other approaches to filter or store stormwater. THINGS TO KNOW

Good Infiltration Capacity

Coarse or sandy loam soils are excessively drained and infiltrate stormwater very quickly. When depth to groundwater is deep (greater than 80 inches), there is no frequency of flooding with such soils. Merrimac fine sandy loam, an example of this soil type, is prevalent throughout much of the western portion of the Lower Mill Pond sub-watershed.

RAPID PERCOLATION

DEEP WATER TABLE

Variable Infiltration Capacity

Stormwater infiltrates more slowly through fine sandy loam, such as Agawam fine sandy loam, which is located to the east of Brickyard Brook. These soils are well or moderately well drained with a depth to groundwater greater than 80 inches, and have little frequency of flooding. This soil type is found intermittently throughout many catchments, creating a variable infiltration capacity in many neighborhoods.

MODERATE PERCOLATION

DEEP WATER TABLE

Medium Infiltration Capacity

Stormwater infiltration capacity is greatly reduced with moderately draining soils and a shallow depth to groundwater (18 to 42 inches). Areas to the northeast of the Lower Mill Pond sub-watershed have Ninigret fine sandy loam and a shallow depth to groundwater.

Low Infiltration Capacity

Stormwater infiltration capacity is the lowest with poorly draining soils and a shallow depth to groundwater (0 to 18 inches). Areas along Brickyard Brook have Saco silt loam and frequent flooding or pooling of water.

MODERATE PERCOLATION VARIABLE DEPTH TO WATER TABLE

SLOW PERCOLATION SHALLOW TO WATER TABLE

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A Neighborhood Strategy for Improving the Lower Mill Pond Watershed

ANALYSIS


Good Infiltration Capacity Many catchments south of Lower Mill Pond and west of Brickyard Brook have soils with excessively well drained soils, >80â&#x20AC;? to groundwater, and thus a fast infiltration capacity. Opportunities exist here to intercept the stormwater and infiltrate it in small, decentralized stormwater management systems before it reaches the pond or wetlands. Variable Infiltration Capacity Moderately drained soils require stormwater systems to be sized to accommodate greater volumes of water in order to maintain the proper rate of infiltration. Because the groundwater is shallow (18-42 inches), it is risky to encourage infiltration as it might flood the

area. Solutions to reduce runoff here will involve holding water in place and infiltrating it as slowly as possible. Medium Infiltration Capacity Moderately drained soils and shallow depth to groundwater require adequate sizing that retain larger volumes of water over a longer period of time to promote infiltration. Low Infiltration Capacity Poorly drained soils and very shallow (018 inches) groundwater around Brickyard Brook represent the lowest infiltration capacity and lie away from the sewer system. This area is where storm sewer outfall pipes discharge stormwater along Plum and Brickyard Brooks.

A Neighborhood Strategy for Improving the Lower Mill Pond Watershed

ANALYSIS

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Intercepting Stormwater: Conditions Above Ground Property ownership and land use should be considered when developing strategies to add green space and green infrastructure.

WHY IT MATTERS Green space and stormwater mitigation features require physical space. Land ownership dictates what measures can be taken at any specific location. FINDINGS The sub-watershed comprises over 1,200 separate parcelsâ&#x20AC;&#x201D;most of them developedâ&#x20AC;&#x201D;presenting a challenge for a sub-watershed-wide approach to improving stormwater. A small number of properties are vacant. A small number of properties are City- or other government-owned, some of which are vacant. IMPLICATIONS Vacant parcels should be kept open and naturally vegetated whenever possible, or developed in a way that minimizes stormwater impacts. Easthamptonâ&#x20AC;&#x2122;s stormwater management ordinance and 40R Smart Growth zoning designation are programmatic efforts that address this issue. Developed, government-owned properties may provide an opportunity to implement stormwater mitigation and green space features. An effective strategy for improving water quality, though, will need to target a range of locations and landowners at a range of scales. THINGS TO KNOW

Parcel Ownership

There are approximately 1,200 separate parcels in the Lower Mill Pond sub-watershed. About 1,000 of these are residential, a mix of single-family homes, apartments, and apartment complexes. A commercial district is concentrated along Union and Cottage Streets downtown, and mill buildings flank the pond to the west, north, and east. Vacant land is concentrated along Plum and Brickyard Brooks and between East Street and Mount Tom State Reservation. Scattered through the sub-watershed are some City-owned and other government-owned properties. These include housing complexes, vacant lots, the Manhan Rail Trail, Lower Mill Pond Park, schools, and municipal buildings. While the City owns some small vacant lots, much of the open, vacant areas in the sub-watershed are privately owned. These vacant parcels are variously developable, as described below.

40R Smart Growth Zoning

Smart Growth Zoning areas, many of which occur in the Lower Mill Pond neighborhood, use a streamlined

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permitting process to encourage high density, mixed-use development and low-income housing. Beyond providing housing for low-income residents in a changing neighborhood, these zoning districts discourage sprawl by giving developers incentives for compact development that may serve to keep open, naturally vegetated areas more intact (Easthampton OSRP).

Stormwater Management Ordinance

The City of Easthampton has taken an innovative approach to integrating stormwater management into future development by enacting a stormwater management ordinance. This regulation requires that new development or redevelopment projects an acre or larger take certain measures to intercept stormwater runoff from the site. Projects between an acre and 10,000 square feet face similar, but less stringent requirements. Approximately one-third of parcels in the sub-watershed, however, do not meet the 10,000-squarefoot threshold of the ordinance and have no stormwater management requirements.

A Neighborhood Strategy for Improving the Lower Mill Pond Watershed

ANALYSIS


Of the over 1,200 separate parcels that make up the Lower Mill Pond sub-watershed, over 1,000 are private residential. Vacant land is concentrated in the central and eastern sections, and government properties are scattered throughout.

A Neighborhood Strategy for Improving the Lower Mill Pond Watershed

ANALYSIS

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A Framework for Taking Action

Opportunities to improve water quality in Lower Mill Pond can be identified at a range of sites and scales throughout the sub-watershed.

MULTIPLE APPROACHES Based on the findings of this report, there is no singular solution to the problem of polluted stormwater discharges to Lower Mill Pond. The landscape of the sub-watershed is dominated by dense residential, industrial, and commercial development. Ownership is divided into over 1,200 separate parcels. Because every property and every person has an affect on stormwater, the approach will need to be as varied as the neighborhood itself. The City may need to take action to implement green infrastructure on its own properties, as well as upgrade its storm sewer infrastructure to improve stormwater quality before it is discharged to the pond. Developers may need to take steps to ensure that development does not increase the flow of polluted stormwater into the storm sewers and into the pond. Homeowners, businesses, and residents may need to change their landscapes and day-to-day practices to ensure that less stormwater, and fewer pollutants, flow into the storm drain.

Guiding principles Certain principles apply to stormwater management at any scale and on any site. While some sites may be more amenable to specific changes, these three principles can guide actions anywhere in the Lower Mill Pond sub-watershed. 1) INFILTRATE: INCREASE GREEN SPACE, DISCONNECT FLOW, REDUCE IMPERVIOUS AREA

Impervious surfaces are central to the problem. Precipitation sheets across impervious surfaces, picks up contaminants, and then flows into storm drains instead of into the ground. Directly Connected Impervious Areas accumulate and convey water into Lower Mill Pond through the storm sewer.

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• Preserve naturally vegetated areas that are already infiltrating stormwater. • Disconnect stormwater flow from roofs to driveways, from lawns to sidewalks, from driveways to streets, from streets to storm drains, and from storm sewers to the pond. • Strategically remove impervious area whenever possible and replace with infiltrating soil and vegetation. 2) CLEAN STORMWATER: REDUCE POLLUTION SOURCES AND INCREASE FILTRATION

Due to site conditions, implementing Principle 1 may not always be feasible. In these cases, the approach should be to minimize the contamination of stormwater that is flowing off the landscape into storm sewers and into the pond. • Minimize the amount of pollutants —such as yard chemicals, pet wastes, and automotive fluids— being deposited on impervious surfaces within the sub-watershed. • Identify and disrupt the main pathways of pollutants from the landscape to the sewer system. • Increase filtration of stormwater with filter strips at the edge of a parking lot, with vegetated swales in a new development, with deep-sump catch basins in the street, or with end-of-pipe systems such as fine particle separators or constructed wetlands. 3) EDUCATE AND FACILITATE: ENGAGE CITIZENS IN THE EFFORT

Every property owner and resident has the ability to improve or degrade water quality in Lower Mill Pond through their property management and daily activities. The responsibility for improvement should be spread

A Neighborhood Strategy for Improving the Lower Mill Pond Watershed

SOLUTIONS


among as many people as possible. • Educate citizens as to how their activities —lawn care, dog-walking, car washing, littering— may contribute pollutants to the pond. • Show property owners, through demonstration sites, workshops, and other outreach, how they can disconnect and infiltrate on their property. Provide technical assistance and material support for implementation. • Continue to enforce legal requirements that developers implement stormwater management measures on new development and redevelopment projects. Provide technical assistance, and material support when possible, to maximize stormwater benefits. 4) TAKE AN OPPORTUNISTIC APPROACH

The opportunistic approach builds stormwater improvements into landscape changes that are already occurring. The current stormwater management ordinance in Easthampton makes use of an opportunistic approach by requiring new and redevelopment projects above a certain size to mitigate their stormwater impacts. In the case of ongoing renovations at the Pleasant Street mill complex, the City worked with developers to obtain grants to improve parking, create green space, and better manage stormwater at the site. Opportunistic recommendations include:

management opportunities. • Implement gray and green infrastructure solutions as part of municipal improvement efforts on new development and redevelopment projects to maximize stormwater opportunities. 5) PURSUE PROACTIVE IMPROVEMENTS

A proactive approach goes a step beyond the opportunistic by initiating water quality improvements on sites for which there are no immediate plans to change land use. This approach can target threats to water quality where they occur, with an emphasis on high-priority sites and catchment areas, whether they are city-owned or private properties. Recommendations include: • Install green and gray infrastructure on City-owned or other government-owned properties. • Preserve vacant and naturally vegetated land for water quality and open space benefits. • Offer stormwater retrofit educational programs for homeowners and businesses. • Develop targeted pollution reduction educational campaigns.

• Continue and enhance the stormwater management ordinance currently in place to address any new NPDES Permit requirements, and encourage green infrastructure. • Support developers, through grants and technical assistance, in maximizing the stormwater

A Neighborhood Strategy for Improving the Lower Mill Pond Watershed

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A VARIED LANDSCAPE AND A VARIETY OF OPPORTUNITIES

Every property in the sub-watershed affects water quality, and improvements should be made at as many sites, and as many types of sites, as possible. Depending on site conditions and ownership status, efforts may range from installing green infrastructure, to giving incentives to homeowners to employ small-site BMPs, to educating residents about pollution reduction. The table below presents stormwater intervention opportunities for a number of site types within the sub-watershed. OWNER TYPE Government

TYPES OF SITES

OPPORTUNITIES FOR CITY ENGAGEMENT

• vacant properties

Maintain undeveloped lands in an open, naturally vegetated state to infiltrate stormwater and provide recreational green space.

• municipal buildings and schools

Install green infrastructure BMP retrofits on developed municipal properties and manage as demonstration sites.

• street-scapes • public housing

Improve streetscapes with green features (such as street trees, planters, pocket parks) for stormwater and quality of life benefits. Integrate with planned road maintenance when possible to minimize costs. Upgrade existing storm sewer gray infrastructure where green infrastructure is unfeasible.

Developers

• residential/ commercial new and redevelopment

Maintain current stormwater management ordinance requirements for new development and re-development of properties. Continue using 40R Smart Growth zoning to encourage compact, mixed use development Encourage and assist developers to exceed required measures through streamlined permitting incentives, technical assistance, and grant funding.

Residents

• owner-occupied Educate citizens about small-site stormwater BMPs using demonstration residences sites, technical assistance and workshops, and material support. • multifamily Give incentives for small-site BMPs. rentals Focus pollution reduction education by neighborhood, targeting areas where increased infiltration is unfeasible.

Conservation • conserved lands Groups • vacant properties

Develop and promote water-quality educational materials for conservation groups. Work closely with conservation groups to acquire and preserve green space through grant funding and conservation restrictions.

SITE DESIGN PROCESS Implementing mitigation measures for a particular location requires a site-specific analysis. The questions below outline a design process that methodically addresses stormwater impacts, appropriate BMP solutions, additional benefits to the neighborhood, and opportunities for engagement and support based on site ownership.

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1) WHERE IS THE WATER FLOWING TO?

Designing stormwater improvements requires zooming in to small, site-scale watersheds to determine where water flowing from the site is draining. Systems should intercept and infiltrate, filter, store, or absorb and evaporate as much stormwater as possible to keep it from running off the site and into the storm sewer system. By examining the locations of catch basins and impervious surfaces, grading and drainage patterns,

A Neighborhood Strategy for Improving the Lower Mill Pond Watershed

SOLUTIONS


mitigation efforts can be located strategically on the site. 2) WHAT ARE THE SOIL CONDITIONS?

As shown in the Infiltration Capacity map (p. 19), soils with different infiltration capacities underlay different areas within the sub-watershed. The best intervention strategy is to restore the infiltration of stormwater to groundwater. In the human landscape, however, it is necessary to consider impacts such as surface flooding, groundwater seepage into basements, and mosquitos. If infiltration of a site’s stormwater volume is not feasible, other strategies may need to be implemented. 3) WHAT BMPS SHOULD BE USED?

Different site conditions, such as infiltration capacity and limitations of the built environment, require different BMPs. Some BMPs are more suitable for storage, filtration, infiltration, absorption or evaporation, or a combination of these mitigation strategies. For descriptions of BMPs, refer to Massachusetts Stormwater Manual Volume 2 Chapter 2 and the Center for Watershed Protection’s Urban Subwatershed Restoration Manual No. 3: Urban Stormwater Retrofit Practices. Planting trees can have various impacts depending on species, tree size, and land use. Based on these characteristics, stormwater sequestration can be estimated via a calculator on treebenefits.com. 4) WHAT OTHER BENEFITS CAN BE REALIZED?

Some green infrastructure systems present an opportunity not only to mitigate the water quality impacts of stormwater, but also to beautify neighborhoods, raise property values, create green spaces for recreation and gathering, provide ecosystem service benefits such as improved air quality, and add wildlife habitat to the landscape.

conditions are appropriate and there is funding available. • Under Easthampton’s stormwater management ordinance, many commercial sites being developed are required to build certain stormwater management measures into their designs. The City can maximise these benefits by encouraging site design that treats stormwater and offers benefits to the neighborhood, such as creating green space. • The majority of properties in the sub-watershed are privately owned residential, commercial, or industrial sites. Though they contribute significantly to stormwater, the City has limited ability to implement green infrastructure or control activities which contribute pollutants. Education and facilitation will be key to implementing solutions on residential property, and should focus on stormwater issues relevant to specific site types and neighborhoods.

SITE PROTOTYPES The following site prototypes are conceptual designs focused on generic locations typical of the Lower Mill Pond neighborhoods. They employ Stormwater Best Management Practices (BMPs) that are based on typical sub-watershed site conditions described in the previous analyses. These examples, and the design process that led to them, are meant to serve as inspiration and guidance as to what measures could be taken at similar sites to achieve project goals. In addition to physical modifications, the site prototypes also describe programmatic recommendations that support and enhance the function of the described designs.

5) WHO OWNS THE SITE, AND WHAT OPPORTUNITIES ARE AVAILABLE?

• The City can make stormwater improvements on its own properties, including municipal buildings, streetscapes, and public housing, provided the site

A Neighborhood Strategy for Improving the Lower Mill Pond Watershed

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Residence with Fast-Infiltrating Soils

A residential property with fast-infiltrating soils has many opportunities to intercept stormwater with small systems that convey, absorb, filter and/or infiltrate.

1) WHERE IS THE WATER FLOWING?

• Stormwater sheets across a rooftop down both sides of the house into downspouts, discharges onto the lawn and driveway and enters the street and storm drain untreated. Permeable surface is estimated to be 82%; that includes lawn, which does not do a very good job of infiltrating stormwater. • Tree cover is estimated to be <1%, which means there is very minimal sequestration of stormwater through absorption by trees. 2) WHAT ARE THE SOIL CONDITIONS?

• Soils have a fast infiltration capacity with excessively well drained soils and groundwater is greater than 80 inches below the surface. These conditions provide opportunities for BMPs that convey, absorb, filter and/or infiltrate stormwater before it reaches the storm drain in the street. 3) WHAT BMPS CAN BE USED?

• Remove pavement and install permeable pavement to encourage infiltration of rain water and snow melt rather than sheet flow toward the storm drain. • Add trees. It is estimated that one red maple with a diameter of 11 inches will sequester 1,218 gallons of stormwater yearly. In this design, tree cover is increased to 28%. • A rain garden absorbs and infiltrates stormwater. However, with the fast infiltration capacity of the soils, selected plant species need to be tolerant of dry conditions most of the time.

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4) WHAT OTHER BENEFITS CAN BE REALIZED?

• Most of the neighborhoods in the Lower Mill Pond Watershed have very low tree cover. New trees and vegetation will sequester not only stormwater but also carbon from the air. If deciduous trees are planted to the south of homes, they can produce shade in the summer, cooling the home and reducing energy use. If evergreen trees are planted to the northwest of homes, they provide a windbreak from winter winds, thereby reducing winter heating costs. Rain gardens can be beautiful and can provide habitat for birds and insects. 5) WHO OWNS THE SITE, AND WHAT OPPORTUNITIES ARE AVAILABLE?

• Offer private property owners incentives to implement BMPs: » Seek grant funds to purchase trees in bulk and offer to landowners at a reduced price. » Work with local garden centers to offer a discount on certain materials for stormwater projects (such as rain barrels or porous pavers). » Work with local suppliers to set up educational displays at stores to provide technical information about new materials and installation. • Provide educational resources and events that teach about pollutants and the importance of changing certain practices (e.g., picking up after your dog while dog-walking or eliminating synthetic fertilizers from landscaping practices).

A Neighborhood Strategy for Improving the Lower Mill Pond Watershed

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Best Management Practices for residential sites such as installing rain barrels, rain gardens, trees and shrubs offer multiple benefits, including privacy screening, reductions in heating and cooling costs and seasonal blooms. BEFORE 82% permeable surface <1% tree cover

Driveway

Road

Catch basin

Lawn

WATER FLOW

AFTER 82% permeable surface 28% tree cover, rain gardens additional

Catch basin

Driveway

Road

Rain gardens intercept, filter and infiltrate runoff before it can get to the street and storm drain.

Rain barrels capture rooftop runoff from gutters and downspouts that can then be used to water lawns or gardens. Add trees and shrubs to soak up stormwater

N

RAIN BARREL

A Neighborhood Strategy for Improving the Lower Mill Pond Watershed

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Residence with Slow-Infiltrating Soils

Residential properties with slow-infiltrating soils need longer retention times for stormwater and potential overflow provisions for larger storm events.

1) WHERE IS THE WATER FLOWING?

• Stormwater sheets over a rooftop down both sides of the house into downspouts, discharges to the lawn and driveway, and enters the street and storm drain untreated. Permeable surface is estimated to be 40% and what little lawn there is does not infiltrate the stormwater very effectively. • Tree cover is estimated to be 0%, which means there is no sequestration of stormwater through absorption by trees. 2) WHAT ARE THE SOIL CONDITIONS?

• Soils have a low infiltration capacity which requires BMPs that hold stormwater in place and slowly convey it towards plants that will absorb it. This is done to avoid flooding of yards and basements. • Connections for overflow to the existing storm sewer should be provided. 3) WHAT BMPS CAN BE USED?

• Remove pavement and install permeable pavement to encourage absorption of rain water rather than sheet flow to the storm drain. • Add trees. As previously stated, one tree can sequester hundreds of gallons of stormwater yearly

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depending on its size and type. In this design, trees now cover 33% of the site. • Rain barrels or cisterns capture rooftop runoff. Multiple barrels may be needed. 4) WHAT OTHER BENEFITS CAN BE REALIZED?

• Many neighborhoods have very low tree cover and there is not much vegetation currently to sequester stormwater in these slowly infiltrating soils. As noted above, new trees and vegetation can also sequester carbon in the air, reduce energy use if planted appropriately, and help create an attractive landscape.

• Stormwater captured in rain barrels can be harvested for watering lawns and gardens. 5) WHO OWNS THE SITE, AND WHAT OPPORTUNITIES ARE AVAILABLE?

• Municipal incentives for homeowners with these kinds of site conditions may be effective. The city is already selling rain barrels at a discounted price one day a year to interested residents. This program could be expanded so that, for example, group discounts are applied. This might inspire residents to work together.

A Neighborhood Strategy for Improving the Lower Mill Pond Watershed

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Trees provide stormwater benefits even when not planted along the street.

BEFORE 40% permeable surface 0% tree cover

Catch basin

Driveway

Lawn

WATER FLOW

AFTER 47% permeable surface 33% tree cover

Layer vegetation for best infiltration. Trees, shrubs, perennials, then ground cover. Shrubs slow and filter runoff before it flows off the site.

Rain barrels capture rooftop runoff that can then be used to water lawns or gardens.

Trees between the driveways absorb stormwater.

Overflow connection to street or catch basin

N

Replace asphalt driveway with permeable pavement to provide groundwater recharge.

Overflow connection to street A runnel, which is a narrow channel, directs driveway runoff to trees planted along driveway.

RAIN BARREL

A Neighborhood Strategy for Improving the Lower Mill Pond Watershed

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Looking at the Neighborhood as a Whole Homeowners are encouraged to make interventions collectively at the neighborhood scale. In this prototypical New City neighborhood, Best Management Practices are implemented throughout both public and private spaces to make a larger impact. 1) WHERE IS THE WATER FLOWING?

• The New City neighborhood comprises two high priority catchment areas that direct stormwater runoff directly into Lower Mill Pond. A large volume of stormwater runs off rooftops, structures, and pavement that are all near one another and connected to the streets and storm sewer system. Permeable surface is estimated to be 43%. • Tree cover is estimated to be 4% in the entire neighborhood, which means there is very minimal sequestration of stormwater through absorption by trees. 2) WHAT ARE THE SOIL CONDITIONS?

• Soils have a low infiltration capacity, which requires BMPs that hold stormwater in place and slowly convey it towards plants which will absorb it. This is done to avoid flooding of yards and basements. 3) WHAT BMPS CAN BE USED?

• Site interventions described in preceding pages can be combined with on-street improvements. Removing pavement and installing trees in planters that bump out into the street will lead to the capture, absorption and filtration of untreated stormwater running off the street and off individual properties. Inflow channels created by curb cuts bring stormwater into the bump-outs from the street for the street trees to capture and absorb. An additional outflow channel directs stormwater overflow to the next bumpout. Trees will have to be very tolerant of these conditions. • Gray infrastructure might be a feasible alternative in New City if the neighborhood runs out of space for tree plantings and other BMPs but would like to do more to reduce stormwater runoff. End-of-pipe

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interventions are viable alternatives to green infrastructure, especially in New City where there is some of the highest acreage of DCIA per acre. Deep sump catch basins along roadways and finishing filters close to the outfall pipe collect sediments, nutrients, and other pollutants. With regular maintenance, these upgrades can help to reduce sediments and unwanted nutrients as a last resort before they enter the pond. • Add trees. It is estimated that three red maples with a diameter of 11 inches will sequester 3,654 gallons of stormwater yearly. If everyone on a street with 30 properties plants a red maple this size, the neighborhood will sequester 36,540 gallons of stormwater yearly. In this design, tree cover is increased from 4% to 63%. 4) WHAT OTHER BENEFITS CAN BE REALIZED?

• New trees and vegetation will not only sequester stormwater but also carbon. If deciduous trees are planted to the south of homes, they can produce shade in the summer time. If evergreen trees are planted to the northwest of homes, they provide a windbreak from winter winds.

• Stormwater captured in rain barrels can be harvested for watering lawn and garden. 5) WHO OWNS THE SITE, AND WHAT OPPORTUNITIES ARE AVAILABLE?

• Homeowners might be incentivized to implement BMPs on their property if the city also agrees to install street trees. • Expand city rain barrel program.

A Neighborhood Strategy for Improving the Lower Mill Pond Watershed

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Trees provide environmental, health, and landscape benefits for a neighborhood.

BEFORE 43% permeable surface 4% tree cover Lawn

WATER FLOW Two-way road Catch basin

Trees: • Protect water quality • Improve air quality

AFTER 50% permeable surface 67% tree cover

• Help save energy • Increase property values

New trees

• Reduce carbon dioxide

One-way road

N

Tree bump-outs must be designed and engineered for healthy trees and to manage stormwater. Inlets and outlets are needed for stormwater to filter through. Engineered soils can alleviate compaction and allow roots to grow (EPA Stormwater to Street Trees).

A Neighborhood Strategy for Improving the Lower Mill Pond Watershed

Two-way road with parking becomes a one-way road with parking to allow room for tree bumpouts.

SOLUTIONS

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Commercial Space Improvements As recreational use of Lower Mill Pond increases and revitalization of the mill buildings and the Union Street neighborhood progresses, BMPs in commercial spaces can benefit both the surrounding ecology and commercial activity. 1) WHERE IS THE WATER FLOWING?

• Add trees. It is estimated that six red maples with a diameter of 11 inches will sequester 7,308 gallons of stormwater yearly. In this design, tree cover is increased from <4% to 28%.

• Tree cover is estimated to be <4%, which means there is very minimal sequestration of stormwater through absorption by trees.

4) WHAT OTHER BENEFITS CAN BE REALIZED?

• Stormwater sheets over a large rooftop, structures, and extensive pavement and enters the street and storm drain untreated. Permeable surface is estimated to be 28%.

2) WHAT ARE THE SOIL CONDITIONS?

• Soils have a medium infiltration capacity, which requires BMPs that hold rain water in place and slowly convey and absorb into plants rather than infiltrate. This is done to avoid flooding of the parking lots and basements.

Green Infrastructure can provide connectivity for wildlife through urban areas from already existing corridors, such as the Metacomet-Monadnock Ridge, Brickyard and Plumb Brooks, the Manhan River and Lower Mill Pond itself.

• More greenery creates an inviting space. Passersby, potential customers of businesses, and employees in office buildings and businesses will feel more comfortable using these spaces, which is good for commerce and ultimately the neighborhood.

3) WHAT BMPS CAN BE USED?

• De-pave between parking spaces to create recessed tree planters that filter and absorb stormwater. Each parking space is reduced to a minimum of 15 feet in length and 8 feet in width. If the size of opposing parking spaces is each 18 feet, this provides a 6-foot-wide space for the recessed tree planters. • Flow-through tree box filters absorb and filter stormwater. • Lawn replaced with shrubs, trees, and groundcovers helps infiltrate the rain. • Wet swales use water-tolerant plants to filter runoff before draining to storm sewer. • A green roof retains rain that is then transpired into the air by the plants, reducing runoff. • Wet-tolerant plants in a depressed bed filter runoff.

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5) WHO OWNS THE SITE, AND WHAT OPPORTUNITIES ARE AVAILABLE?

• Municipal incentives for owners of private commercial property with these kinds of site conditions may be effective. For example, the city could offer to advertise a business’s use of BMPs to the community to give that company some good public relations. The City could also offer to establish a volunteer program with training and funding that goes towards an urban forestry program. • Business owners might be invited to implement BMPs on their property on the condition that the City also agrees to install street trees. More trees in general will get more people outside, which is beneficial to both community and commerce.

A Neighborhood Strategy for Improving the Lower Mill Pond Watershed

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Located in an area of town with the most Directly Connected Impervious Area (DCIA), this office building and parking lot could use some greening. BEFORE 28% permeable surface <4% tree cover

Lawn

Asphalt parking lot

Road

Road

Catch basin

Catch basin WATER FLOW

AFTER 43% permeable surface 28% tree/shrub cover Catch basin

Wet-tolerant plants in depressed bed filter runoff.

A green roof retains rain that is then transpired into the air by the plants, reducing runoff and heat island effects.

Wet swale uses watertolerant plants to filter runoff before draining to storm sewer.

Lawn is replaced with shrubs, trees, and groundcovers to help infiltrate the rain.

Catch basin Reduced parking space depth makes room for a recessed tree planter

Flow-through planter filters and absorbs stormwater then drains into the storm sewer.

N A Neighborhood Strategy for Improving the Lower Mill Pond Watershed

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Institutional Prototype Government and school buildings showcase Best Management Practices to the community. At these demonstration sites, students learn stormwater concepts and residents can learn what they can do on their properties. 1) WHERE IS THE WATER FLOWING?

• Stormwater sheets over a large rooftop, structures, and extensive pavement and enters the street and storm drain untreated. Permeable surface is estimated to be 15%. • Tree cover is estimated to be <3%, which means there is very minimal sequestration of stormwater through absorbtion by trees. 2) WHAT ARE THE SOIL CONDITIONS?

• Soils have a high infiltration capacity with excessively well drained soils and groundwater that is greater than 80 inches below the surface. Interventions should intercept and infiltrate the stormwater without increasing flooding of the property. 3) WHAT BMPS CAN BE USED?

• De-pave to make room for re-vegetation and green infrastructure. • Rain barrels or cisterns capture rooftop runoff, which supplies water for vegetable garden beds. • A field is slightly recessed by 6 to 12 inches so that it holds water during storm events and infiltrates it into the soil instead of allowing it to run off the site. Planted with native low-grow grass or ground covers, it requires minimal mowing but provides green space for children to play. • Swale with shrubs and trees absorbs runoff. • Permeable pavement infiltrates stormwater. • Rain garden filters and infiltrates stormwater that flows from the vegetated swale and serves as a demonstration garden for children and parents. Overflow is filtered before going into the storm drain.

Recreational resources such as raised garden beds and a naturalistic play space offer opportunities for multiple uses of the property, transforming the property into a recreational resource to the community. • Vegetable plants, a berry patch, and permaculture garden provide ecosystem services to pollinator species and other habitat. The roots of new plants also enrich the soil, making it suitable for native habitat to thrive. 5) WHO OWNS THE SITE, AND WHAT OPPORTUNITIES ARE AVAILABLE?

• Distribute educational flyers throughout schools that display to the students the changes to the public spaces and why they are important. Incorporate this outreach with existing lesson plans in water science. • Inform parents of the changes on school grounds, describe to them the design process, why the BMPs are important, and invite them to learn from this example to make changes to their properties. • Get the community involved in the implementation of the BMPs and organize a volunteer project. With training, a group of volunteers can accomplish much in one day of service. While major excavation and de-paving might be best contracted out, volunteers can plant trees, construct raised garden beds, install rain barrels, and more. In the process, members of the community are learning how to implement these BMPs and will have the knowledge to do so on their properties or their neighbors’ properties. • Raise the awareness of students, teachers, and parents of how good housekeeping and reducing pollutants in the first place can help. One example might be organizing regular volunteer clean-ups of the grounds.

• Vegetable garden beds, a berry patch and a permaculture garden filter and absorb stormwater.

• These same BMPs might be an appropriate consideration for privately owned institutional properties such as private schools.

4) WHAT OTHER BENEFITS CAN BE REALIZED?

• If multiple properties have one owner, training and use of equipment may be more efficiently organized.

• Spaces with more nature produce a friendlier and cleaner environment in which children can learn more effectively. The ecosystem services that BMPs provide can be an effective educational resource for students learning about ecology or water science.

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A Neighborhood Strategy for Improving the Lower Mill Pond Watershed

SOLUTIONS


School yards offer an opportunity for education of children, parents and community in stormwater remediation. BEFORE 15% permeable surface

Road

Catch basin

Road

<3% tree cover

Asphalt parking lot School

Asphalt play area

WATER FLOW

Playground

AFTER

Runnel breaks flow of water from parking lot and directs it to the rain garden.

63% permeable surface 23% tree/shrub cover

Rain garden and swales have informational signs explaining benefits.

Catch basin

Rain garden Trees absorb stormwater while shading the playground and the parking lot.

Asphalt parking lot School

Rain garden

Permeable pavement

Recessed play area holds water for infiltration during storms.

Road

Rain barrels capture rooftop runoff to supply water for gardens.

Teaching garden

N

Garden beds and berry bushes

Playground with permeable mulch. Playground

De-pave

Vegetated swales absorb and filter runoff. Native grasses and/or ground cover for no-mow lawn.

Fruit trees RAIN BARREL

A Neighborhood Strategy for Improving the Lower Mill Pond Watershed

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35


Greenspace A vacant property, previously paved for parking, finds new life as a community garden and natural playscape for children.

1) WHERE IS THE WATER FLOWING?

4) WHAT OTHER BENEFITS CAN BE REALIZED?

• Tree cover is estimated to be 25% which means there is minimal sequestration of stormwater through absorption by trees.

• Recreational resources such as raised garden beds and a naturalistic play space offer opportunities for multiple uses of the property, transforming the property into a resource to the community rather than an eye-sore.

• Stormwater sheets over extensive pavement and enters the street and storm drain untreated. Permeable surface is estimated to be 2%.

2) WHAT ARE THE SOIL CONDITIONS?

• Soils have a medium infiltration capacity which requires that BMPs hold rain water in place and slowly convey and absorb into plants rather than infiltrate. This is done to avoid flooding of neighboring yards and basements. 3) WHAT BMPS CAN BE USED?

• De-pave and replace with permeable pavement to allow for the natural absorbing of rain water rather than sheet flow toward the storm drain. • A swale with shrubs and trees conveys, filters, and infiltrates stormwater toward a rain garden. With the slow infiltration capacity of the soils, a ditch or culvert will direct the treated overflow toward the nearest storm drain.

• Additional public green space is created in the neighborhood.

• Vegetable plants, a berry patch, and permaculture garden provide ecosystem services to pollinator species and other habitat. The roots of new plants also enrich the soil, making it suitable for native habitat to thrive. 5) WHO OWNS THE SITE, AND WHAT OPPORTUNITIES ARE AVAILABLE?

• As owner of these sites, the municipality can be opportunistic and make changes to properties that produce as many benefits as possible where resources are available. • The site can be designated as an educational field trip destination for school groups where they can learn more about BMPs.

• Vegetable garden beds, a berry patch and a permaculture garden filter and absorb stormwater. • Add trees. It is estimated that twelve red maples with a diameter of 11 inches will sequester 14,616 gallons of stormwater yearly. In this design, tree cover increases from 25% to 48%.

36

A Neighborhood Strategy for Improving the Lower Mill Pond Watershed

SOLUTIONS


This vacant parcel in New City becomes a neighborhood green space, playground, and community garden. BEFORE 2% permeable surface 25% tree cover Catch basin

Road

Asphalt parking lot

Existing line of trees

WATER FLOW

AFTER 100% permeable surface 48% tree/shrub cover Catch basin

Swale with shrubs and trees absorb and filters runoff before exiting to storm drain.

NW windbreak/screen

Rain garden overflows to storm sewer in high rain event

Community garden provides space for fruit trees and berry bushes as well as individual garden beds.

Permeable parking area Shrubs stop flow of stormwater off of site.

Natural playscape area provides space for unstructured play in a natural environment. Existing vegetation provides a shady area to sit or play. De-pave entire lot and re-vegetate for stormwater infiltration and green space for the community.

N A Neighborhood Strategy for Improving the Lower Mill Pond Watershed

SOLUTIONS

37


Case Study: SEA Streets, Seattle, WA An urban community uses streetscape designs to reduce harmful impacts of stormwater, add green space and wildlife habitat, and beautify neighborhoods. The city of Seattle, Washington, implemented a project to study and address rainwater runoff by designing a system that more closely mimics the natural landscape prior to development than traditional piped systems do. The project is known as the Street Edge Alternatives Project (SEA Streets) and the pilot was completed in 2001 in a residential neighborhood in the north end of the city. Seattle Public Utilities (SPU) planners used a Natural Drainage System (NDS) to manage the stormwater from the street by mimicking natural methods in which land absorbs rainwater and reduces the quantity of runoff. By absorbing more rain there is less runoff to wash over the land picking up contaminants on its way to a stream or pond. SPU also reduced the impervious surfaces to 11 percent less than a traditional street. After several years of monitoring, it was found that the natural stormwater treatment system reduced the total volume of stormwater by 99 percent.

The SEA Street design cleanses stormwater through a series of natural functions. The plants and soils filter pollutants from the rainwater as it moves through the swales, preventing them from traveling downstream to the rivers, steams, or ponds. Bacteria within healthy soils can also help break down carbon-based pollutants like motor oil. This would also work well along parking areas.

The initial study area was one city block but has since been implemented in additional areas because it was shown to work so well. The cost for the first street was $850,000, which included an extensive design budget. Subsequent projects will cost less than traditional street improvements, according to Seattle Public Utilities. Because they like the way the new plantings improve the look of their neighborhoods, local residents have taken responsibility for caring for the plantings, reducing maintenance work for the city. Reducing the amount of impervious surfaces city-wide had a major impact on stormwater runoff by giving the rain a place to soak in. http://www.seattle.gov/

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SEA Street created landscaping that is both useful and beautiful so that it created a sense of place as well as filtered stormwater. Grasses, sedges and rushes physically filter pollutants out of stormwater. The project designers followed the concept of "right plant, right place," selecting non-invasive species that can survive with little maintenance in their climate. Trees with smaller root systems fit more easily within the right-of-way; plants that thrive in wetlands have been placed in the lower, moist areas of the stormwater swales and ponds.

A Neighborhood Strategy for Improving the Lower Mill Pond Watershed

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Additional Resources

• Massachusetts DEP handbook with detailed explanations of Best Management Practices and their uses: Volume 2 Chapter 2: Structural BMP Specifications for the Massachusetts Stormwater Handbook • Use of trees and structural soil to mitigate urban runoff: Day, S.D, and S.B. Dickinson (Eds.) 2008. Managing Stormwater for Urban Sustainability Using Trees and Structural Soils. Virginia Polytechnic Institute and State University, Blacksburg, VA. • Center for Watershed Protection’s Urban Watershed Repair Manual series, including desktop analysis, field assessment, and how to make critical restoration management decisions: www.cwp.org/online-watershed-library/cat_view/64-manuals-and-plans • Manual 1, An Integrated Framework to Restore Small Urban Watersheds, Version 2.0 • Manual 2, Methods to Develop Restoration Plans for Small Urban Watersheds, Version 2.0 • Manual 3, Urban Stormwater Retrofit Practices, Version 1.0 • Manual 8, Pollution Source Control Practices, Version 2.0 • Streetscapes for decreasing the amount of stormwater runoff and pollution: Stormwater to Street Trees: Engineering Urban Forests for Stormwater Management www.davey.com/media/183712/Stormwater_to_Street_Trees.pdf • Use of CU-Structural Soil™ for urban trees, while also fulfilling engineers’ load-bearing requirements: Using CU-Structural Soil™ in the Urban Environment www.hort.cornell.edu/uhi/outreach/pdfs/custructuralsoilwebpdf.pdf • Structural soil in tree planting: CU-Structural Soil™ Graphics and Plan Views www.hort.cornell.edu/uhi/outreach/csc/graphics.html • Achieving more green space in street and parking lot design: San Mateo County Sustainable Green Streets and Parking Lots Design Guidebook First Edition ~ January 2009 www.flowstobay.org/documents/municipalities/sustainable%20streets/San%20Mateo%20Guidebook.pdf • Online tool for calculating a tree’s value in a community: National Tree Benefits Calculator www.treebenefits.com/calculator/ • How to site, size, design, and install a rain garden: Rain Gardens: A Design Guide for Connecticut and New England Homeowners nemo.uconn.edu/raingardens/

A Neighborhood Strategy for Improving the Lower Mill Pond Watershed

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Data Sources for Maps

WATERSHEDS Context Section, Page 4 DATA SOURCES: MassGIS

• Drainage Sub-basins (December 2007) • MassDEP Hydrography (1:25,000) (March 2010) • Community Boundaries (Towns) (February 2014) Conway Team

• Lower Mill Pond sub-watershed (March 2015)

WETLANDS

Context Section, Page 5 DATA SOURCES: MassGIS

• MassDEP Wetlands (1:12,000) (January 2009) • Massachusetts Department of Transportation (MassDOT) Roads (June 2014) Conway Team

• Lower Mill Pond sub-watershed (March 2015)

ECOLOGICAL INTEGRITY AND HABITATS

Context Section, Page 6

DATA SOURCES: MassGIS

• MassDEP Wetlands (1:12,000) (January 2009) • Massachusetts Department of Transportation (MassDOT) Roads (June 2014) • USGS Color Ortho Imagery (2014) (April 2014) • BioMap (February 2011) UMass Amherst Conservation Assessment and Prioritization System

• CAPS 2011 data for Massachusetts

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A Neighborhood Strategy for Improving the Lower Mill Pond Watershed

DATA SOURCES FOR MAPS


SUB-BASIN AND SUB-WATERSHED DIRECTLY CONNECTED IMPERVIOUS AREA

Context Section, Page 10 DATA SOURCES: MassGIS

• Impervious Surface (February 2007) • MassDEP Hydrography (1:25,000) (March 2010) • Drainage Sub-basins (December 2007) Conway Team

• Lower Mill Pond sub-watershed (March 2015)

SUB-BASIN AND SUB-WATERSHED DIRECTLY CONNECTED IMPERVIOUS AREA

Analysis Section, Page 13 DATA SOURCES: MassGIS

• MassDEP Hydrography (1:25,000) (March 2010) Conway Team

• Catchment Delineations (March 2015) Easthampton Department of Public Works

• storm_drainage_line.shp (February 2002) • outfall.shp (February 2002) CATCHMENT PRIORITIES

Analysis Section, Page 15 DATA SOURCES: MassGIS

• Impervious Surface (February 2007) • MassDEP Hydrography (1:25,000) (March 2010) Conway Team

• Catchment Delineations (March 2015)

A Neighborhood Strategy for Improving the Lower Mill Pond Watershed

DATA SOURCES FOR MAPS

41


ENVIRONMENTAL JUSTICE AREAS

Analysis Section, Page 16 DATA SOURCES: MassGIS

• Level 3 Assessors’ Parcel Mapping (2012) • MassDEP Hydrography (1:25,000) (March 2010) • 2010 U.S. Census - Environmental Justice Populations (December 2012) Conway Team

• Catchment Delineations (March 2015)

LAND USE AND OPEN SPACE

Analysis Section, Page 17 DATA SOURCES: MassGIS

• Level 3 Assessors’ Parcel Mapping (2012) • MassDEP Hydrography (1:25,000) (March 2010) • Land Use (2005) (June 2009) Conway Team

• Catchment Delineations (March 2015)

INFILTRATION CAPACITY

Analysis Section, Page 19 DATA SOURCES: MassGIS

• Level 3 Assessors’ Parcel Mapping (2012) • MassDEP Hydrography (1:25,000) (March 2010) Conway Team

• Catchment Delineations (March 2015) USDA-NRCS Web Soil Survey

• Soil type and classification (accessed February 2015)

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A Neighborhood Strategy for Improving the Lower Mill Pond Watershed

DATA SOURCES FOR MAPS


PARCELS

Analysis Section, Page 21 DATA SOURCES: MassGIS

• Level 3 Assessors’ Parcel Mapping (2012) • MassDEP Hydrography (1:25,000) (March 2010) Conway Team

• Catchment Delineations (March 2015) Easthampton Assessor’s Office

• Parcel Ownership (accessed February 2015) • Zoning Districts (accessed February 2015)

A Neighborhood Strategy for Improving the Lower Mill Pond Watershed

DATA SOURCES FOR MAPS

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References

Austin, Gary. Green Infrastructure for Landscape Planning: Integrating Human and Natural Systems. Abingdon, Oxon and New York, NY: Routledge, 2014. Print. Bassuk, Nina, Jason Grabosky, and Peter Trowbridge, Using CU-Structural Soil™ in the Urban Environment. Ithaca, NY: Urban Horticulture Institute of Cornell University, 2005. Print. Bassuk, Nina. “Tree Roots and Tree Health: How Much Soil Does a Tree Need?” Cornell Cooperative Extension Horticulture’s videos, Vimeo. Vimeo, LLC, 3 Oct. 2011. Web. 20 Mar. 2015. “BioMap 2: Conserving the Biodiversity of Massachusetts in a Changing World.” mass.gov. MA: Executive Office of Energy and Environmental Affairs, 2015. Web. 5 Mar. 2015 “Brickyard Brook Conservation Area.” Pascommuck Conservation Trust. Easthampton, MA: Pascommuck Conservation Trust, n.d. Web. 20 Mar. 2015. Carr, Jamie W. and Laurie E. Kennedy, “Connecticut River Watershed 2003 Water Quality Assessment Report.” Mass.gov. Report Number: 34-AC-2, DWM Control Number: CN 105.5. Worcester, Massachusetts: Massachusetts Department of Environmental Protection Division of Watershed Management, 2008. Web. Casey Trees and Davey Tree Expert Co. “National Tree Benefits Calculator.” treebenefits.com. n.p., n.d. Web. 19 Mar. 2015. Center for Watershed Protection, Online Watershed Library (OWL) n.p., 2015. Web. 5 Mar. 2015. City of Griffin, GA. “What is Stormwater?” cityofgriffin.com. n.p., 2014. Web. 27 Jan. 2015. City of Seattle. “Seattle SEA Streets Drain Naturally.” Solaripedia.com. n.p., 2011. Web. 28 Jan. 2015. “Conservation Assessment and Prioritization System” (CAPS). umasscaps.org. Center for Agriculture, Food and the Environment, n.d. Web. 5 Mar. 2015. “CU-Structural Soil™ Graphics and Plan Views.” Urban Horticulture Institute. New York: Cornell University Department of Horticulture, 2007. Web. 20 Mar. 2015. Day, S.D, and S.B. Dickinson (Eds.) Managing Stormwater for Urban Sustainability Using Trees and Structural Soils. Virginia Polytechnic Institute and State University, Blacksburg, VA. 2008. Print. Francese, Stacey and Jay Rasku. Conservation and Land Use Planning under Massachusetts’ Chapter 61 Laws. Athol, MA: Mount Grace Land Conservation Trust, Inc., 2007. Print. Leslie, Jacques. “Los Angeles, City of Water.” The New York Times. 4 Dec. 2014. Nytimes.com. Web 27 Jan. 2015. Leu, Chelsea. “How Green Spaces are Saving Humanity.” Sierra Club. Sierra Club, 2014. Web. 6 Feb. 2015. Massachusetts Department of Energy and Environmental Affairs. Massachusetts Stormwater Handbook Volume 2 Chapter 2: Stormwater Best Management Practices. n.p., 2015. Web. 25 Feb. 2015. Matsuno, Hiroko, and Selina Chiu. “The Stormwater Management Challenge.” Nacto.org. Seattle, 2001. Web. 27 Jan. 2015. Nevue Ngan Associates and Sherwood Design Engineers. San Mateo County Sustainable Green Streets and Parking Lots Design Guidebook. First Edition. n.p., 2009. Print. Parker, Sally. “Demand an Urban Forest that Works for Us.” Center for Leadership in Global Sustainability. Virginia Polytechnic Institute and State University. 2012-2015. Web. 5 Mar. 2015. Philadelphia Water Department, Office of Watersheds. A Homeowners Guide to Stormwater Management. n.p., Jan. 2006. Web. 27 Jan. 2015. Philadelphia Water Department. Philly Watersheds. Philadelphia, PA. 2015. Web. 27 Jan. 2015.

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A Neighborhood Strategy for Improving the Lower Mill Pond Watershed

REFERENCES


Pioneer Valley Planning Commission. Easthampton, MA Open Space and Recreation Plan. 2013-2020. n.p., 2013. Print. Pioneer Valley Planning Commission with the Nashawannuck Pond Restoration Project Advisory Committee. “Nashawannuck Pond Watershed Restoration Project.” Nashawannuckpond.org. Project No. 1998-05/319. n.p., n.d. Print. “Pollutants of Concern.” cnyrpdb.org/stormwater/ Central New York Stormwater Coalition, n.d. Web. 5 Mar. 2015. “Rain Gardens; A Design Guide for Connecticut and New England Homeowners.” Nemo.uconn.edu. University of Connecticut Center for Land Use Education and Research’s NEMO, n.d. Web. 19 Mar. 2015. Reardon, Matthew. “Re: Background Info DCIA.” Message to Alex Krofta. 24 Mar. 2015. E-mail. Roseen, Robert M., Todd V. Janeski, James J. Houle, Michael H. Simpson, and Jeff Gunderson. “Forging the Link: Linking the Economic Benefits of Low Impact Development and Community Decisions.” University of New Hampshire Stormwater Center. Chapter 2: Benefits of Low Impact Development. Millerworks, 2010. Web. 5 Mar. 2015. Seattle Public Utilities. “RainWise Program.” Seattle.gov n.p., n.d. Web. 28 Jan. 2015. Seattle Public Utilities. “Street Edge Alternative.” Seattle.gov. n.p., n.d. Web. 28 Jan. 2015. Sherer, Paul M. ”The Benefits of Parks: Why America Needs More City Parks and Open Space.” The Trust for Public Land. n.p., 2006. Web. 12 Feb. 2015. Sutherland, Roger. C, P.E., “Methods for Estimating Effective Impervious Cover,” Article 32 in The Practice of Watershed Protection, Center for Watershed Protection, Ellicott City, MD, 2000. http://www.stormwatercenter.net/ Library/Practice/32.pdf “Tree Facts.” American Forests. n.p., 2015. Web. 5 Mar. 2015. U.S. Department of Housing and Urban Development. “Community Block Grant Program.” HUD.gov. n.p., n.d. Web. 10 Feb. 2015. U.S. Department of the Interior. “Evapotranspiration – The Water Cycle” U.S. Geological Survey. n.p., 2014. Web. 20 Mar. 2015. U.S. EPA. (2010). EPA’s Methodology to Calculate Baseline Estimates of Impervious Area (IA) and Directly Connected Impervious Area (DCIA) for Massachusetts Communities. Boston, MA. http://www.epa.gov/region1/ npdes/stormwater/ma/IA-DCIA-Calculation-Methodology.pdf US Environmental Protection Agency. “Estimating Change in Impervious Area (IA) and Directly Connected Impervious Areas (DCIA) for Massachusetts Small MS4 Permit.” Epa.gov. n.p., 2014. Web. US Environmental Protection Agency. “The CADDIS Urbanization Module” (PDF version). Epa.gov. CADDIS Volume 2: Sources, Stressors & Responses. n.p., 2010. Web. U.S. Environmental Protection Agency Office of Wetlands, Oceans and Watersheds Nonpoint Source Control Branch. Stormwater to Street Trees: Engineering Urban Forests for Stormwater Management. n.p., September 2013. Web. 19 Feb. 2015. Verrilli, Ann, and Jennifer Raitt. The Use of Chapter 40R in Massachusetts. n.p., October 2009. Web. 27 Jan. 2015.

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Created and developed to meet the needs of industry, Lower Mill Pond in Easthampton, Massachusetts, and its nearby neighborhoods have changed as the economy has shifted. Today, places rendered derelict and obsolete by a decline in manufacturing are being re-visioned, re-purposed, and re-integrated into the cultural and economic landscape.

A Neighborhood Strategy for Improving the Lower Mill Pond Watershed Easthampton, Massachusetts

Today, non-point source pollution and stormwater runoff are the major threats to the pond. Implementation of best management practices will require not only an understanding of site-speciďŹ c conditions, but also a programmatic framework that promotes solutions at all scales. Vacant property could be acquired, protected, and restored as naturally vegetated green space for passive recreation. New and redevelopment projects requiring zoning review and permits are opportunities to work collaboratively with project proponents to include green infrastructure elements that capture and treat stormwater on site and add trees and other plants to the neighborhood. Municipal properties and the street right-of-way may present the most readily accessible locations for implementing green infrastructure, planting street trees, and educating the public through demonstration sites.

The Conway School is the only institution of its kind in North America. Its focus is sustainable landscape planning and design and its graduates are awarded a Master of Science in Ecological Design degree. Each year, through its accredited, ten-month graduate program students from diverse backgrounds are immersed in a range of real-world design projects, ranging from sites to cities to regions. Graduates play signiďŹ cant professional roles in various aspects of landscape planning and design. Fix whatâ&#x20AC;&#x2122;s broken. Save what works. Design the future!

Prepared for the City of Easthampton The Conway School - Winter 2015

Profile for The Conway School

A Neighborhood Strategy for Improving the Lower Mill, Easthampton, Mass.  

Created and developed to meet the needs of industry, Lower Mill Pond in Easthampton, Massachusetts, and its nearby neighborhoods have change...

A Neighborhood Strategy for Improving the Lower Mill, Easthampton, Mass.  

Created and developed to meet the needs of industry, Lower Mill Pond in Easthampton, Massachusetts, and its nearby neighborhoods have change...