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Clean Energy Toolkit Topic: Alternative Energy

“Alternative energy” is a phrase used to describe technologies that help increase energy efficiency and reduce reliance on conventional fossil-fuel based electricity generation, but do not qualify as clean or renewable energy sources. Energy efficiency is often conceptualized as a clean energy resource, and many consider efficiency resources to be nearly unlimited. Although ISO-New England recognizes efficiency as a capacity resource, Massachusetts does not recognize efficiency technologies such as cogeneration as qualified renewable generating units. Instead, they fall under the category of “alternative energy” and are prioritized differently in terms of funding. The Alternative Portfolio Standard(APS) was established in January of 2009 as a result of the Green Communities Act. It requires a certain percentage of the state’s electric load to be met by eligible “alternative energy” technologies. Read more.

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What is Mixed Use?

Traditional zoning was developed during a time when factories and many commercial uses were noisy, smelly, and/or hazardous to the public. To protect public health and residential property values, early zoning focused on separating different uses and buffering them from each other to minimize nuisances.

Today, much commercial development is environmentally benign, and there are often advantages to locating different uses in close proximity. Mixed use concentrated development, preferably near transit, is seen as a key “smart growth” tool to reduce auto dependence and preserve green space and natural resources. Thus many communities are turning to “mixed use,” which generally refers to a deliberate mix of housing, civic uses, and commercial uses, including retail, restaurants, and offices.

Mixing uses, however, works best when it grows out of a thoughtful plan that emphasizes the connectivity and links among the uses. Results may be haphazard when communities simply enable multiple uses without providing guidance about the mix of uses and how they are spatially related.

To achieve well-planned mixed use development, most of the bylaws described in this guide are “overlay” districts. This means that the underlying zoning remains in place. Developers may choose to develop according to the underlying zoning or, alternatively, according to the mixed use provisions. The overlay encourages coordinated, cohesive development among lots or through lot consolidation. The overlay approach is especially useful when the community wants to promote a unified approach in an area where there are two or more underlying districts.

If the community wants to encourage mixed use, the overlay should be structured to be attractive to developers and the requirements should not be onerous. The municipality typically retains control through the special permit process and can turn down any development not to its liking.

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How Are Other States Attaining Development Mitigation?

Other states have mitigation practices that are not currently used in Massachusetts. Below is a list of key practices used in other states.

Land Banking (Colorado)

Land banking is the practice of purchasing land with the intent to hold on to it until such a time as it is profitable to sell it to others for more than was initially paid. Municipalities can use land banking to retain some control over the future development of a particular area, such as suburban sprawl, preserve green space or to prevent growth from occurring. Through land banking, municipalities can control how land is developed. The City of Fort Collins, Colorado practices Land Banking. Their website is a good resource on this subject.

Concurrency (Florida and Washington)

Concurrency is a growth management concept intended to ensure that necessary public facilities are available concurrent with the impacts of development.

In Florida, a Growth Management Act was adopted in 1985 which requires all of the state’s counties and municipalities to adopt Local Government Comprehensive Plans that guide future growth and development.

The comprehensive plans are required to contain chapters or “elements” that address future land use, housing, transportation, infrastructure, coastal management, conservation, recreation and open space, intergovernmental coordination, and capital improvements. A key component of the Act is its “concurrency” provision that requires facilities and services to be available concurrent with the impacts of development.

  • Read more about concurrency in the State of Florida.
  • Download(13 MB) the Florida Department of Community Affairs’ Transportation Concurrency Best Practices Guide.
  • Review an an ordinance from Citrus County, Florida.

In Washington, concurrency means that adequate public facilities are in place to serve new development as it occurs. Passed in 1995, the Growth Management Act (GMA) gives special attention to concurrency for transportation. The GMA requires each city and county in Washington to periodically review and, if needed, revise their comprehensive plans and development regulations to ensure that they comply with the GMA. Read more about concurrency in the State of Washington.

Transportation Development Districts (New Jersey)

Transportation Development Districts (TDDs) are regional districts created voluntarily by municipal and/or county governments to fund transportation infrastructure costs. Costs of infrastructure improvements are borne by the public sector (taxpayers) and private developers under a predetermined cost-sharing formula based upon traffic generation or other criteria associated with the development that occasions the need for additional investment in infrastructure.

A TDD must have a plan of development, and should be consistent with other land use and development plans. The overall goal of the TDD is to manage growth and coordinate and finance transportation infrastructure improvements in a regional growth area. The TDD plan identifies transportation infrastructure improvements that will be needed within the District to support anticipated development. The transportation goals of the TDD are to maintain acceptable traffic flows, protect quality of life for existing residents and make alternatives to the single occupancy auto more attractive.

Click here for information about Mercer County, New Jersey’s TDD.

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What Are Possible Development Mitigation Strategies?

Legal Considerations

It is essential to understand the context for requiring development mitigation. In 1966, the Home Rule Amendment was added to the Massachusetts Constitution. The Amendment created a limited home rule mechanism granting certain powers to cities and towns and enabled municipalities to adopt charters without needing state approval. The purpose of the Home Rule Amendment is to “grant and confirm to the people of every city and town the right of self-governance in local matters.” Although the Amendment does give municipalities the ability to adopt charters, state statutes can still preempt local laws.

There are also legal considerations involved in the design of development mitigation. First, a “rational nexus” must be demonstrated between the impacts caused by a development and the nature of the mitigation required. Second, there must be a “rough proportionality” between the extent of the impacts generated and the extent of the mitigation required. It must be shown that new development creates the need for mitigation. The Central Artery/Tunnel project or ‘Big Dig’ is an example of a transportation project that implemented various types of development mitigation. Read more about the Central Artery/Tunnel project’s mitigation programs.

Setting Strategies

With the context set, possible development mitigation strategies can be explored. It is critical that a community be explicit about their desired mitigation. This requires building relationships, multi-community coordination, and partnerships. Possible mitigation strategies fall into two main categories: Transportation Demand Management (TDM) and Transportation Infrastructure.

Impact Fees are another possible strategy, however at present, these fees are not expressly permitted in the state.

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Parking Benefit Districts

Signed in to law in late 2016, the Municipal Modernization Act allows Massachusetts cities and towns to create what is known as a parking benefit district. Parking benefit districts is a specified geography in which the parking revenues raised are then reinvested back into the district for a wide range of transportation-related improvements. The funds may be used to purchase the meters themselves, invest in walking and biking infrastructure, or pay for improvements to the public realm, such as street trees, benches, and lighting.

For more information on this tool, please see the one-pager or contact Kasia Hart, Transportation Policy Associate, at [email protected] or 617-933-0745.

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What Are Other Initiatives That Support Development Mitigation?

Smart Growth

Smart Growth provides a framework for communities to make informed decisions about how and where they grow. Smart Growth enables communities to grow in ways that support economic development and jobs; create strong neighborhoods with a range of housing, commercial and transportation options; and achieve healthy communities with a clean environment.

Massachusetts Sustainable Development Principles

The State’s Sustainable Development principles are intended to care for the built and natural environment by promoting sustainable development through the integration of energy, environmental, housing, and transportation agencies’ policies, programs and regulations. The principles encourage investing public funds wisely in smart growth and equitable development.

Massachusetts Smart Growth/Smart Energy Toolkit

toolkit was prepared by the Executive Office of Energy and Environmental Affairs (EOEEA) to assist in the implementation of smart growth/smart energy. Access to information on planning, zoning, subdivision, site design, and building construction techniques is available on this website.

Smart Growth America

Smart Growth America is a coalition of national, state and local organizations working to improve the ways towns, cities and metro areas are planned and built.

Smart Growth Network

In 1996, the U.S. Environmental Protection Agency joined with several non-profit and government organizations to form the Smart Growth Network. The Network was formed in response to increasing community concerns about the need for new ways to grow that boost the economy, protect the environment, and enhance community vitality. Environmental groups, historic preservation organizations, professional organizations, developers, real estate interests; local and state government entities are among the Network’s partners. Smart Growth.org is a web-based catalogue of smart growth related news, events, information and resources.

Complete Streets

A growing national movement, road networks are increasingly being designed to be safer, more livable, and welcoming to all users. Instituting a Complete Streets policy, ensures that an entire roadway is consistently designed and operated to balance safety and convenience with all users in mind – including bicyclists, public transportation vehicles and riders, and pedestrians of all ages and abilities.

Each Complete Street has its own unique characteristics. Examples of components that may be found on a complete street include sidewalks, bike lanes, special bus lanes, comfortable and accessible transit stops, intersection and crosswalk improvements for non-motorized users, median islands, accessible pedestrian signals, and curb extensions.

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How are Development Impacts Identified?

When the scale or nature of the project indicates that there may be significant traffic impacts to the surrounding transportation network and facilities, the potential type and scale of impacts need to be identified. These impacts are identified at the state and municipal levels, and how a development’s effect on transportation is determined.

At the State Level

The Massachusetts Environmental Policy Act (MEPA) is a uniform system of environmental impact review to reduce the potential for harm to the environment from certain development, construction or other projects. MEPA was established as a state law in the late 1970s (MEPA Regulations, 301 CMR 11.00).

The intent of MEPA review is to inform project proponents and state agencies of potential adverse environmental impacts while a proposal is still in the planning stages. The private proponent identifies required state agency actions and describes the means by which the proposal complies with applicable regulatory standards and requirements. The private proponent and all relevant state agencies are required to identify any aspects of the proposal that require additional description or analysis prior to completion of the agency action, most commonly the issuance of a certificate and Section 61 Findings, which are described below.

MEPA provides a state regulatory framework primarily aimed at accomplishing two goals:

  1. Ensure that public and private agencies participating in projects are aware of their potential environmental impacts before taking action, including permitting and financial assistance.
  2. Ensure that prior to taking action with respect to projects, state agencies should “use all practicable means and measures to minimize damage to the environment.”

MEPA also requires studying alternatives to the proposed project and developing enforceable mitigation commitments, which will become permit conditions for the project.

MEPA Review Thresholds

According to MEPA Regulations Section 11.03: Review Thresholds, a MEPA review is required when one or more review thresholds are met or exceeded and the subject matter of at least one review threshold is within MEPA jurisdiction. Review thresholds identify categories of projects that are likely to cause “Damage to the Environment.” There are two tiers of MEPA thresholds:

  1. ENF (Environmental Notification Form) and an EIR (Environmental Impact Report)
  2. ENF and other MEPA review if required by the Secretary

The review thresholds fall into twelve categories, of which Transportation is one. For example, an ENF and an EIR is required if a project proposes the construction of 1,000 or more new parking spaces at a single location. An ENF and other MEPA review are required if a project proposes the construction of 300 or more new parking spaces at a single location.

Section 61 Findings

Section 61 Findings require state agencies and authorities to review, evaluate and determine the impacts on the natural environment of all projects or activities requiring permits issued by the state. Findings are issued describing the environmental impacts, if any. All feasible measures that have been taken by the project proponent to avoid or minimize these impacts are certified. Section 61 is a requirement of Massachusetts General Laws (Chapter 30, Section 61. M.G.L. c.30, s.61).

Although Section 61 Findings provide a “template” for permit conditions, MEPA is not responsible for issuing permits. Participating state agencies are responsible for issuing permits (e.g., Massachusetts Department of Transportation Highway Division issues Highway Access Permits).  To enforce mitigation requirements, a municipality can link their permit requirements with that of state agencies. For more information regarding monitoring and enforcement, go to How is Development Mitigation Monitored and Enforced? (hyperlink)

Additional MEPA Resources

At the Municipal Level

Cities and towns have tools that help to identify potential development impacts. Primary among these tools are a Master Plan and Community Development Plan.

Master Plans and Community Development Plans

Master Plans and Community Development Plans document a municipality’s existing conditions, issues, and projects. Both are good resources that document a municipality’s present condition and provide guidance for accomplishing community visions and intentions through public investments, land use regulations and other programs. More specifically, these plans assess the long-term capital project requirements of a municipality.

Chapter 41: Section 81D of Massachusetts General Laws requires a planning board established in any city or town to prepare a Master Plan. The Master Plan is comprised of several elements, including a Goals and Policies Statement, a Land Use Element, a Housing Element and an Open Space and Recreation Element.

Most relevant to assessing possible development impacts are the Circulation Element and the Implementation Program Element. The Circulation Element provides an inventory of existing and proposed circulation and transportation systems. Information from this element feeds into the Implementation Element, which defines and schedules the specific municipal actions necessary to achieve the objectives of each element in the plan. As new developments occur, these two elements can assist the municipality in making choices about how projects should be implemented, financed, and phased over time.

In response to an increasing shortage of housing across Massachusetts, both for individuals and in particular families with low, moderate, and middle-incomes, Executive Order 418 (EO418) was enacted in 2000. Through EO418, planning funds were offered to all Massachusetts communities to help them develop Community Development Plans that would identify future opportunities while linking housing with economic development, transportation, open space, and resource protection.

The transportation component of the Community Development Plans addressed the location and description of transportation improvements, including matters of safety, access, congestion and transit, intermodal connections and environmental considerations. Communities were required to discuss regional transportation issues, define regional transportation problems, and develop recommendations to address these problems. Although Community Development Plans are no longer being developed, they can provide a context for assessing how new development could impact the local and regional transportation system and for identifying mitigations.

The Executive Office of Housing and Economic Development maintains background information on Executive Order 418 and a list of Community Development Plans that have been submitted by Massachusetts municipalities.

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Sustainable Agriculture: Municipal Food System Toolkit

Project Background

Farmers Market

What is a food system? At what scale does it operate? How can I improve my local food system?

The Municipal Food System Toolkit for MAPC Communities was created by CLF Ventures (CLFV), Conservation Law Foundation’s consulting affiliate, in partnership with MAPC, to answer these types of questions and provide resources for municipalities to support their important role in sustaining the Massachusetts food system.

The Massachusetts Food Policy Council defines a food system as “a complex, adaptive network with the flow of food products through production, processing, distribution, consumption and waste management,” as shown in the diagram below.

Food System Diagram

Essentially, a food system includes every part of the process that puts food on our tables—from seed to plate. The Massachusetts food system includes locally produced foods, as well as imported foods that supplement our supply.

MAPC’s Role

MAPC’s Sustainable Communities Program, funded by the U.S. Department of Housing and Urban Development, supported CLFV’s development of the Toolkit. The Toolkit includes tools and resources designed to guide municipal officials through the process of improving their local food systems.

The project supports the following MetroFuture goals:

  • # 42: The region’s agricultural economy will grow through a focus on sustainable farming and by bringing more locally produced foods to the market.
  • #65: A robust network of protected open spaces, farms, parks, and greenways will provide wildlife habitat, ecological benefits, recreational opportunities, and scenic beauty.

Why it’s Important

Food system activities create economic value; residents and communities benefit from access to affordable, safe, fresh, and healthy food; and locally grown food can reduce the environmental impacts associated with mono-cropping and long distance transport. In addition, supporting agriculture-related enterprises, such as composting and related food service businesses, in Massachusetts communities can create jobs, expand the market for locally grown and processed food, and keep food dollars in the local economy.

Resources

Project Resources

Municipal officials should use this Toolkit as they work with agricultural producers, residents, and other stakeholders to identify their food system priorities, assess the current state of their local system, and implement projects that will improve the quality of life in their communities.

The Toolkit is divided into seven chapters:

  • Chapters 1 and 2 – Food System Education
  • Chapter 3 – Connecting Food System Issues to Municipal Priorities.
  • Chapter 4 – Creating a Food System Group and Conducting a Local Food System Assessment
  • Chapter 5 – Community Engagement and Stakeholder Analysis
  • Chapter 6 – Tools
  • Chapter 7 – Case Studies/Projects

The full Toolkit can be accessed below.

Additional Resources

MAPC Resources:

  • Massachusetts Food System Plan project
  • Minuteman Advisory Group on Interlocal Coordination Agricultural Planning Program

External Resources:

  • Massachusetts Department of Agriculture
  • Municipal Assoc. of Agricultural Commissions
  • UMass Extension Center for Agriculture

Questions?

For more information, please contact Heidi Stucker, Regional and Food System Planner (617-933-0739 or [email protected]) or Jasmine Tanguay, CLFV Managing Director, (617-850-1787 or [email protected]).

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Parking and Transportation Demand Management

Reducing the demand for parking is closely linked with reducing vehicle trips, so many of the programs recommended for reducing parking demand are the same ones recommended for trip reduction through Transportation Demand Management (TDM). TDM programs typically aim to reduce drive-alone trips through strategies that encourage carpooling or use of alternative modes.

Because TDM programs reduce solo driving, less parking is needed; communities should account for this and reward employers who implement effective TDM programs through reductions to minimum parking requirements, allowing these employers to shed parking spaces they no longer need or build fewer to begin with.

TDM programs are most commonly implemented at large job sites, especially in suburban areas, but many components are also appropriate for large multi-family residential developments, and some can be implemented at the district or community level.

They offer the greatest benefits to employers that are constrained by their parking supply, those that can realize a financial benefit by using fewer spaces (for example, if the spaces are leased separately), or those that wish to redevelop a portion of their parking into usable building space. The community also benefits from reduced traffic and impervious surfaces.

DM strategies include:

For more information on TDM in Massachusetts, including services for employers, travel options for employees, and tax benefits, see the MassRIDES website and the MassCommute website.

Locally, the City of Cambridge has an ordinance linking parking and TDM. The ordinance was introduced in 1998 in response to growing concerns about traffic impacts from new development, following extensive discussions with City council, the public, and the Chamber of Commerce.

The Parking and Transportation Demand Management Ordinance is triggered by construction or expansion of parking facilities, and applies to all non-residential projects. Small projects (5-19 parking spaces) must implement 3 TDM measures; large projects (20 or more spaces) must prepare a PTDM plan for city review and approval, commit to a certain maximum percent of trips to the site that will be made by people driving alone, and monitor biannually how people get to the site and how much parking is being used.

The City credits the program with resulting in smaller parking facilities, less traffic generated by the regulated projects, improved air quality, and better commute options for employees of the impacted work sites. For more information, see the city’s PTDM website. The full text of the ordinance can be downloaded from there.

Cash Out Programs

Many employers, particularly in suburban or lower density areas, offer their employees free parking. This encourages employees to drive to work by disconnecting the costs of parking from the choice to drive. In addition, though the parking seems free, the costs may be borne by employees indirectly as lower wages, so that all employees pay for parking, even if they don’t use it. To remove this unfair incentive to drive alone, some companies are implementing parking cash out programs, offering employees who do not drive the value of a parking space as cash. This offers a financial incentive to employees not to drive, and thus can reduce the demand for parking.

Studies in California showed that cashing out employer-subsidized parking reduced driving to work by 11 %. In California, state law stipulates that employers that offer free parking must offer cash out programs as an alternative, and that cities must grant reduced parking requirements for developments that offer cash out programs. The law also states that existing developments can reduce the parking spaces provided by an appropriate amount if they implement parking cash out, allowing businesses to expand into land previously used for parking.

Cash out programs are often easier to implement than charging for parking because employees are used to parking for free. Also, the effectiveness of a cash out program depends on the availability of alternative modes, and, conversely, the availability of free and unregulated parking in the area (which allows employees to take the cash but still drive and park somewhere). There are also important tax considerations because employers and employees are both taxed on the cash out. Putting the money towards pre-tax transit passes can help resolve this issue.

For more information:

 

Provide Free or Subsidized Transit Passes

Red Line MBTA in Boston, Mass.Employers may provide their employees with free or subsidized transit passes regardless of their parking usage, or may provide the discount only to those who forgo a parking space as part of a parking cash out program.

Through federal legislation passed as a part of the Transportation Equity Act of the 21st Century, participating employers can offer federal tax-free commuter benefits for transit and vanpool expenses to employees, in any amount up to $100 per month .

One study found that when employers began to offer free transit passes, the percent of commuters driving to work alone fell from 76% to 60%, transit mode share more than doubled, and commuter parking demand dropped by 19% [1, p.251-252]. Results will vary based on the quality and proximity of transit service to the site; for sites not well served by transit, a subsidy will be ineffective unless shuttle service connecting the site to transit is also provided.

Transit agencies in Dallas, Denver, Salt Lake, and San Jose, among others, allow employers to buy “EcoPasses,” permitting all employees to ride free on local transit lines. The EcoPasses are sold at a steep discount because they are purchased for all employees, and not all employees will use them fully.

Though not everyone will stop driving to work, by providing everyone with free access to transit, even those who usually or occasionally drive and park will have no marginal cost for using public transit occasionally. This can reduce parking demand for the employer, and can also benefit the community because those employees may choose to use transit for non-work trips as well, reducing traffic further. Because of the reduced parking demand, Montgomery County, Maryland allows office uses a 15% reduction in minimum parking requirements if the business provides reimbursement to employees for transit passes. The same can be applied to residential developments, as a free transit pass makes people less likely to own a car.

For more information:

 

Priority Parking for Carpools and Vanpools

Employers that have their own parking facilities can encourage carpooling and/or vanpooling by reserving prime parking spots – close to building entrances, covered, or otherwise preferable – for carpool or vanpool vehicles. These spaces should not be closer than handicap parking spaces, but should offer an advantage over other parking. Municipalities can do the same in public parking facilities, and may also consider enacting regulations stipulating that operators of private parking facilities must offer priority to carpools and vanpools.

For example, the City of Portland (OR) requires that office, industrial, and institutional uses with minimum parking requirements over 20 spaces must reserve 5% of the spaces or 5 spaces, whichever is less, for carpools. The spaces must be the closest to the building entrance or elevator other than handicap spaces.

Bike Parking and Amenities

Bicycle parkingMaking bicycling an attractive option for accessing a site can reduce the traffic and parking demand at the site.

While a non-scientific internet survey by MAPC found that having a safe route is often the most important consideration for potential bicyclists, a third of survey respondents said that if better bike parking were available, they would ride a bike more often for shopping and visiting friends.

A quarter of respondents said they would bike to work more often if there were showers available and 21% listed secure, covered bike parking as a factor that would encourage them to bike to work.

This demonstrates the potential to increase biking and consequently reduce parking demand and traffic through the provision of parking and amenities for cyclists.

MAPC offers a regional bike parking procurement program that offers communities in MAPC’s region with the opportunity to purchase bike racks or related equipment and receive full reimbursement for the purchase.

In addition to providing bike parking for public facilities, communities may wish to require bike parking for new developments, or even existing uses, as well.

A number of communities in greater Boston have already done this, including:

None of these communities allow reductions to the vehicle parking in exchange for bike parking, but in Portland (OR), every 5 bike parking spaces beyond the required number can substitute for 1 required car parking space.

The type of facilities appropriate will depend on the site and the users: short-term users such as shoppers will need convenient parking close to building entrances; long-term users will value security and protection from the elements for their bike, and employees in particular are likely to value shower and changing facilities at their destination.

For more information:

 

Car Sharing Services

Car sharing programs provide a fleet of vehicles distributed throughout neighborhoods that members can rent on an hourly or daily basis. Members are charged based on usage, usually at a rate that covers gas, maintenance, insurance, and parking. The cars typically have reserved parking spaces at transit nodes and in neighborhoods where they can easily be reached on foot. Car sharing is most effective in higher-density, mixed-use areas where there are other transportation alternatives.

By allowing occasional access to a car without the vehicle ownership, car sharing programs can reduce the need to own a car, especially a second or third one. Zipcar, a for-profit car sharing company operating in Massachusetts, reports that over 40% of its members decide against buying a car or opt to sell one they already own, and that each Zipcar replaces over 20 privately owned vehicles. Because of this benefit, some local governments reduce minimum parking requirements if developers or employers agree to institute or participate in car sharing programs.

Developers may be required to contribute funding towards set up costs and/or to provided dedicated parking for the car-sharing vehicles. The City of Seattle, for example, allows a reduction of up to 5% in the required parking spaces for projects that provide parking for a recognized car-sharing program. Several developments in San Francisco have been allowed significant reductions in their parking requirements, in part because of participation in car sharing programs.

Shuttle Service and Off-Site Parking

Shuttle service and/or off-site parking can work in a number of ways:

  • Shuttle service can be provided to a site from a transit stop, allowing users to forgo driving completely for the trip.
  • Public parking lots or structures can be built at the edges of a downtown area and shuttle service can be provided within the downtown, encouraging people to park once on the outskirts rather than drive into the downtown, potentially making several stops. In some cases, park-and-ride lots can be used for this purpose.
  • Remote parking and shuttles can also be useful for beaches, special events, and other attractions with limited parking and high peak demands. This may be part of an overflow parking plan or may be part of standard operations.

In order to be successful, remote parking requires good information, including signs and maps directing drivers to the location as well as ideally information available online so that people can plan where they will park in advance. In order to be worth the extra trouble of taking a shuttle to the destination, it also must offer advantages over other choices.

For example, if parking is very limited or significantly more expensive near the destination, there will be an incentive to use remote parking. If the price difference is limited or there is parking available closer, peripheral facilities may be underused while near-destination parking is overly congested.

The Boston Region MPO has a Suburban Mobility program through which communities can apply for funding to implement transit services in suburban areas, such as shuttle services. The purpose of the program is to address transportation needs in areas that are currently not served or underserved by transit.

For more information, see the MPO’s website or contact MAPC.

Local examples include:

  • The Ipswich-Essex Explorer provides seasonal shuttle bus service from the commuter rail station in Ipswich to Crane Beach and several other local destinations. It has been operating for 2 years, and is run by the Cape Ann Transit Authority. For more information, see www.ipswich-essexexplorer.com.
  • The Town of Rockport, with high summer demand and limited parking downtown, offers free parking in a park-and-ride lot on the outskirts of the downtown and shuttle service into downtown.
  • The Longwood Medical Area in Boston is served by a number of shuttles to transit stops and remote park-and-ride lots. Most shuttles are free of charge for employees who register through their employer. See more information

National examples include:

  • Baltimore (MD): A Downtown Area Shuttle connects over 1,200 parking spaces near Ravens stadium to various employment sites and the downtown. Commuters pay $50 a month for use of the parking at Ravens stadium and the shuttle service (carpools pay just $20 a month). Others can ride the shuttle around downtown for 50 cents but do not have access to the parking. [2, p.13]
  • Chattanooga (TN): To reduce traffic and air pollution downtown, the city developed two public parking garages, one on either side of their linear CBD, and offers a free shuttle service into the downtown. The parking and shuttles are open to employees and visitors. The electric-powered shuttles are funded by revenue from the parking garages, and run every 5 minutes all day. Roughly 1 million people use them each year. [4, p.20]

Sources:

  1. Donald Shoup, The High Cost of Free Parking (2005), Planners Press, American Planning Association. Available for purchase
  2. Maryland Governor’s Office of Smart Growth, Driving Urban Environments: Smart Growth Parking Best Practices, March 2006.
  3. The Metropolitan Area Planning Council, Regional Bicycle Plan, March 2007.
  4. U.S. Environmental Protection Agency, Parking Spaces / Community Places: Finding the Balance Through Smart Growth Solutions, January 2006. Available as a free download.
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Fact Sheet: Bioretention Areas

Bioretention is an important technique that uses soil, plants and microbes to treat stormwater before it is infiltrated or discharged. Bioretention “cells” are shallow depressions filled with sandy soil, topped with a thick layer of mulch, and planted with dense vegetation. Stormwater runoff flows into the cell and slowly percolates through the soil (which acts as a filter) and into the groundwater; some of the water is also taken up by the plants. Bioretention areas are usually designed to allow ponded water 6-8 inches deep, with an overflow outlet to prevent flooding during heavy storms. Where soils are tight or fast drainage is desired, designers may use a perforated underdrain, connected to the storm drain system.

A “rain garden” bioretention cell for rooftop and driveway runoff. Photo courtesy of University of Connecticut.

Management Objectives

  • Provide water quality treatment; remove suspended solids, metals, nutrients
  • Increase groundwater recharge through infiltration.
  • Reduce peak discharge rates.
  • Reduce total runoff volume.
  • Improve site landscaping

Bioretention areas can provide excellent pollutant removal and recharge for the “first flush” of stormwater runoff. Properly designed cells remove suspended solids, metals, and nutrients, and can infiltrate an inch or more of rainfall. Distributed around a property, vegetated bioretention areas can enhance site aesthetics. In residential developments they are often described as “rain gardens” and marketed as property amenities. Routine maintenance is simple and can be handled by homeowners or conventional landscaping companies, with proper direction.

Applications and Design Principles

Bioretention systems can be applied to a wide range of development in many climatic and geologic situations; they work well on small sites and on large sites divided into multiple small drainages. Common applications for bioretention areas include parking lot islands, median strips, and traffic islands. Bioretention is a feasible “retrofit” that can be accomplished by replacing existing parking lot islands or by re-configuring a parking lot during resurfacing. On residential sites they are commonly used for rooftop and driveway runoff.

A parking lot bioretention cell the day after a storm. Bioretention areas are designed to store water for no more than 72 hours after a storm. Photo courtesy of Rich Claytor.

Bioretention cells are usually excavated to a depth of 4 feet, depending on local conditions. Generally, cells should be sized (based on void space and ponding area) to capture and treat the water quality volume (the first 0.5” or 1” of runoff, depending on local requirements.) Some manuals suggest a minimum width of 15’, though much narrower bioretention cells have been installed in parking lot islands and are functioning well. Regardless of size, some type of filter should cover the bottom of the excavation. Filter fabric is commonly used but can be prone to clogging; consequently some engineers recommend a filter of coarse gravel, over pea gravel, over sand.

The cell should be filled with a soil mix of sandy loam or loamy sand. The area should be graded to allow a ponding depth of 6-8 inches; depending on site conditions, more or less ponding may be appropriate. The area should be planted with a mix of herbaceous perennials, shrubs, and (if conditions permit) understory trees that can tolerate intermittent ponding and occasionally saline conditions (due to road salt.) The soil should be covered with 2-3” of fine-shredded hardwood mulch.

Schematic bioretention plan

A schematic bioretention plan.

In very permeable soils, some bioretention areas can be designed as “off-line” treatment structures (no overflow necessary), but in most situations they will be an “on-line” component of the stormwater management system, connected to downstream treatment structures through an overflow outlet or an overflow drop inlet installed at the ponding depth and routed to the site’s stormwater management system. Ideally, overflow outlets should be located as far as possible from runoff inlets to maximize residence time and treatment. In general, bioretention area should be designed to drain within 72 hours. In slowly permeable soils (less than 0.3 inches/hour) a perforated underdrain can be installed at the bottom of the excavation to prevent ponding.

Bioretention areas work best if designed with some pretreatment, either in the form of swales or a narrow filter strip. A stone or pea gravel diaphragm (or, better yet, a concrete level spreader) upstream of a filter strip will enhance sheet flow and better pre-treatment.

Benefits and Effectiveness:

  • Bioretention areas remove pollutants through filtration, microbes, and uptake by plants; contact with soil and roots provides water quality treatment better than conventional infiltration structures. Studies indicate that bioretention areas can remove 75% of phosphorus and nitrogen; 95% of metals; and 90% of organics, bacteria, and total suspended solids. Bioretention areas qualify as an organic filter according to the Massachusetts Stormwater Policy.
  • In most applications, bioretention areas increase groundwater recharge as compared to a conventional “pipe and pond” approach. They can help to reduce stress in watersheds that experience severe low flows due to impervious coverage.
  • Low-tech, decentralized bioretention areas are also less costly to design, install, and maintain than conventional stormwater technologies that treat runoff at the end of the pipe. The use of decentralized bioretention cells can also reduce the size of storm drain pipes, a major driver of stormwater treatment costs.
  • Bioretention areas enhance the landscape in a variety of ways: they improve the appearance of developed sites, provide wind breaks, absorb noise, provide wildlife habitat, and reduce the urban heat island effect.

Limitations:

  • Because bioretention areas infiltrate runoff to groundwater, they may be inappropriate for use at stormwater “hotspots” (such as gas stations) with higher potential pollutant loads. On these sites, the design should include adequate pretreatment so that runoff can be infiltrated, or else the filter bed should be built with an impermeable liner, so that all water is carried away by the underdrain to another location for additional treatment prior to discharge.
  • Premature failure of bioretention areas is a significant issue that results from lack of regular maintenance. Ensuring long-term maintenance involves sustained public education and deed restrictions or covenants for privately-owned cells.
  • Bioretention areas must be used carefully on slopes; terraces may be required for slopes >20%.
  • The design should ensure vertical separation of at lease 2’ from the seasonal high water table.

Maintenance:

Bioretention requires careful attention while plants are being established and seasonal landscaping maintenance thereafter. In many cases, maintenance tasks can be completed by a landscaping contractor working elsewhere on the site.

  • Inspect pretreatment devices and bioretention cells regularly for sediment build-up, structural damage, and standing water.
  • Inspect soil and repair eroded areas monthly. Re-mulch void areas as needed. Remove litter and debris monthly.
  • Treat diseased vegetation as needed. Remove and replace dead vegetation twice per year (spring and fall.)
  • Proper selection of plant species and support during establishment of vegetation should minimize—if not eliminate—the need for fertilizers and pesticides.
  • Remove invasive species as needed to prevent these species from spreading into the bioretention area.
  • Replace mulch every two years, in the early spring.
  • Upon failure, excavate bioretention area, scarify bottom and sides, replace filter fabric and soil, replant, and mulch.

Cost:

Bioretention areas require careful design and construction, the price of which will depend on site conditions and design objective. Generally, the cost of bioretention areas is less than or equal to that of a catch basin and underground chambers intended to treat the same area. Additionally, bioretention areas treat and recharge stormwater thereby reducing the amount/size of piping needed and the size of downstream basins and treatment structures.

Design Details

  • Where bioretention areas are adjacent to parking areas, allow 3” of freeboard above ponding depth to prevent flooding.
  • Determine the infiltrative capacity of the underlying native soil through an infiltration test using a double-ring infiltrometer. Do not use a standard septic system percolation test to determine soil permeability.
  • Soil mix should be sandy loam or loamy sand with clay content less than 15%. Soil pH should generally be between 5.5-6.5, which is optimal for microbial activity and adsorption of nitrogen, phosphorus, and other pollutants. Planting soils should be 1.5-3% organic content and maximum 500ppm soluble salts.
  • Planting soils should be placed in 1’-2’ lifts, compacted with minimal pressure, until desired elevation is achieved. Some engineers suggest flooding the cell between each lift placement in lieu of compaction.
  • Planting plan should generally include one tree or shrub per 50 s.f. of bioretention area, and at least 3 species each of herbaceous perennials, shrubs, and (if applicable) trees to avoid a monoculture. Plants should be able to tolerate intermittent flooding, occasionally saline conditions, and extended dry periods.
  • The bioretention landscaping plan should meet the requirements of any applicable local landscaping requirements.
  • During construction, avoid excessive compaction of soils around the bioretention areas and accumulation of silt around the drainfield.
  • In order to minimize sediment loading in the treatment area, only runoff from stabilized drainage areas should be directed to bioretention areas; construction runoff should be diverted elsewhere.

Additional References:

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