Town of Groton, MA Town Center Overlay District

The volume of water to be recharged shall be calculated using existing site conditions and the infiltration rates set forth below:

	Hydrologic Soil Group	Quantity to Recharge (inches of runoff)
	A	0.6
	B	0.35
	C	0.25
	D	0.10

The volume of runoff to be recharged shall be calculated as follows:

Recharge Volume (ft³) = Impervious Area (ft²) X Quantity to Recharge (inches)/12

The following criteria also apply:

Initial exfiltration during the design storm shall not be accounted for during the unit/device sizing, with the exception of roof runoff devices, which may account for exfiltration in sizing calculations.

All units/devices shall be designed to drain completely with no standing water within 72 hours from the end of the storm.

Recharge shall not be concentrated to one area. It shall be distributed to multiple areas throughout the site.

The recharge volume criteria does not apply to any portion of a site designated as a stormwater hotspot. Hotspots are defined in the Massachusetts Department of Environmental Protection Volume One: Stormwater Policy Handbook as sites with higher potential pollutant loads, including:

Auto salvage yards (auto recycler facilities).

Auto fueling facilities (gas stations).

Fleet storage areas (cars, buses, trucks, public works).

[4]

Vehicle service and maintenance areas.

[5]

Vehicle and equipment cleaning facilities.

[6]

Commercial parking lots with average trip generation rates of 1,000 or greater per day, such as fast-food restaurants, convenience stores, high-turnover (chain) restaurants, shopping centers, and supermarkets.

[7]

Road salt storage and loading areas (if exposed to rainfall).

[8]

Commercial nurseries.

[9]

Flat metal (galvanized metal or copper) rooftops of industrial facilities.

[10]

Outdoor storage and loading/unloading areas of hazardous substances.

[11]

SARA 312 generators (if materials or containers are exposed to rainfall).

[12]

Marinas (service, repainting, and hull maintenance areas).

Pretreatment.

To prevent premature failure, the design of stormwater treatment devices shall include a pretreatment device or method that will trap sand and sediments to avoid clogging the treatment mechanism. Infiltration of stormwater from the treatment device into underlying soils and eventually groundwater aquifers is an important beneficial component of the device. Pretreatment basins must be designed and located to be easily inspected and accessible to facilitate maintenance. Pretreatment devices must also be sized to accommodate a minimum of one year's worth of sediment and debris.

The following standards shall be followed to ensure that the device will permit sufficient treatment to treat stormwater and allow for a reasonable required maintenance frequency for the best management practice (BMP):

Pretreatment devices shall be provided for each structural BMP; and

Pretreatment devices for bioretention areas should include a grass buffer or transition zone between pavement and bioretention (e.g., crushed stone entrance, cobbles) that allows sediment to drop out before entering the treatment device; and

Pretreatment devices shall be designed to capture anticipated pollutants, such as oil and grease; and

Pretreatment devices shall be designed and located to be easily accessible to facilitate inspection and maintenance; and

The Revised Universal Soil Loss Equation (RUSLE) (Note: developed by the Natural Resources Conservation Service, USDA to predict soil erosion to due water) shall be used to calculate sediment deposits that would occur from pervious areas adjacent to the BMP; and

(f)

Pretreatment structures shall be sized to hold an annual sediment loading. An annual sediment load shall be calculated using a sand application rate of 500 pounds/acre for sanding of roadways, parking areas and access drives within the subcatchment area, a sand density of 90 pounds per cubic foot and assuming a minimum frequency of 10 sandings per year. To obtain an annual sediment volume, perform the following calculation:

Area to be sanded (acres) x 500 pounds/Acre-storm ÷ 90 pounds/ft³ x 10 storms/year = cubic feet of sediment/year

(g)

The developer shall maintain any BMPs used to trap sediment during construction to prevent sediment from leaving the site, and shall remove all sediment from all BMPs when construction is finished and the site is stabilized.

Flooding protection. The following standards should be followed to control peak discharge rates and improve the overall effectiveness of the BMPs. These are minimum design standards.

The post-development peak discharge rate shall be equal to or less than the pre-development (e.g., forested) peak discharge rate (based on a two-year and ten-year, twenty-four-hour storm); and

The post-development peak discharge rate shall be equal to or less than the existing development peak discharge rate based on a one-hundred-year, twenty-four-hour storm;

The site shall be designed to ensure that all runoff from the site up to the one-hundred-year storm enters the control structure. For example, the drainage system may only be sized to handle a ten-year storm, with larger storms flooding the distribution system and traveling overland. This overland flow, or overflow, must be directed into the peak control structure; and

The applicant shall account for all run-on and run-off (including off-site impacts) in both pre- and post-development conditions; and

The applicant shall prepare hydrographs for pre- and post-development conditions; and

The pre-developed condition shall be a forested land cover in good condition; and

(7)

Use TR-55 to develop hydrographs and peak flow rates for the proposed development site. Make sure all areas are accounted for in the pre-/post-runoff calculations. The total tributary area that contributes flow from the proposed site, including runoff entering the site through piped drainage or surface runoff from off-site sources, must be included even if a portion does not contribute flow to the BMP. The objective is for the development's storm drain design to account for total runoff leaving the site; and

(8)

The length of overland sheet flow used in t_c calculations shall be limited to no more than 100 feet for pre- and post-development conditions; and

(9)

Use naturalized basins over typical detention basins for peak control. Naturalized basins are attractively landscaped basins that fit better into a natural landscape, with naturally landscaped areas at the ground surface. Naturalized planting themes incorporate native plants and use an informal pattern to mimic the natural environment; and

(10)

Basins shall be easily accessible for maintenance.

Water quality volume. The water quality volume required to be treated shall be calculated as:

Water Quality Volume (ft³) = Impervious Surfaces (ft²) X 1.0 (inch) / 12 (inches per foot)

Pollutant removal. Stormwater management systems must be designed to remove 80% of the average annual post-construction load of total suspended solids (TSS).

Erosion control. Land clearing and grading for construction purposes leaves soils susceptible to erosion. If not controlled, eroded soils may reach streams and lakes, filling them in and adding pollutants attached to the soil particles. It is important to have controls in place to prevent and control the erosion of disturbed lands. The following standards shall be met for erosion control:

Prior to any land disturbance activities commencing on the site, the developer shall physically mark limits of no land disturbance on the site with tape, signs, or orange construction fence, so that workers can see the areas to be protected. The physical markers shall be inspected daily; and

Appropriate erosion and sediment control measures shall be installed prior to soil disturbance. Measures shall be taken to control erosion within the project area. Sediment in runoff water shall be trapped and retained within the project area. Wetland areas and surface waters shall be protected from sediment; and

Sediment shall be removed once the volume reaches 1/4 to 1/2 the height of the silt fence or hay bale; and

Divert off-site runoff from highly erodible soils and steep slopes to stable areas; and

Land disturbance activities requiring a stormwater management permit under Chapter 198, Stormwater Management — Low-Impact Development, must submit a sequencing plan that requires stormwater controls to be installed and the soil stabilized. A construction phasing plan shall be submitted to the Planning Department prior to any construction on the site. Mass clearings and grading of the entire site shall be avoided; and

Soil stockpiles must be stabilized or covered at the end of each workday. Stockpile side slopes shall not be greater than 2:1. All stockpiles shall be surrounded by sediment controls; and

(7)

The area of disturbance shall be kept to a minimum. Disturbed areas remaining idle for more than 14 days shall be stabilized; and

(8)

For active construction areas such as borrow or stockpile areas, roadway improvements and areas within 50 feet of a building under construction, a perimeter sediment control system shall be installed and maintained to contain soil; and

(9)

A tracking pad shall be constructed at all entrance/exit points of the site to reduce the amount of soil carried onto roadways and off the site; and

(10)

Dust shall be controlled at the site; and

(11)

On the cut side of roads, ditches shall be stabilized immediately with rock rip-rap or other nonerodible liners or, where appropriate, vegetative measures such as sod; and

(12)

Permanent seeding shall be undertaken in the spring from March through May, and in late summer and early fall from August to October 15. During the peak summer months and in the fall after October 15, when seeding is found to be impractical, an appropriate temporary mulch shall be applied. Permanent seeding may be undertaken during the summer if plans provide for adequate mulching and watering; and

(13)

All slopes steeper than 3:1 (h:v, 33.3%), as well as perimeter dikes, sediment basins or traps, and embankments must, upon completion, be immediately stabilized with sod, seed and anchored straw mulch, or other approved stabilization measures. Areas outside of the perimeter sediment control system must not be disturbed; and

(14)

Monitoring and maintenance of erosion and sediment control measures throughout the course of construction shall be required. The applicant shall submit an Operation and Maintenance Plan for temporary and permanent erosion control measures as part of the application package; and

(15)

Temporary sediment trapping devices must not be removed until permanent stabilization is established in all contributory drainage areas. Similarly, stabilization must be established prior to converting sediment traps/basins into permanent (post-construction) stormwater management facilities. All facilities used as temporary measures shall be cleaned prior to being put into final operation; and

(16)

All temporary erosion and sediment control measures shall be removed after final site stabilization. Disturbed soil areas resulting from the removal of temporary measures shall be permanently stabilized within 30 days of removal.

Hydrologic and hydraulic criteria for all designs.

Impervious cover is measured from the site plan and includes any material or structure on or above the ground that prevents water from infiltrating through the underlying soil. Impervious surface is defined to include, without limitation: paved parking lots, sidewalks, rooftops, driveways, patios, and paved, gravel and compacted dirt surfaced roads.

The specified design storms shall be defined as a twenty-four-hour storm using the rainfall distribution recommended by the United States Department of Agriculture (USDA) Natural Resources Conservation Service (NRCS).

Proposed residential, commercial, or industrial subdivisions shall apply these stormwater management criteria to the land development as a whole. Individual lots in new subdivisions shall not be considered separate land development projects, but rather the entire subdivision shall be considered a single land development project. Hydrologic parameters shall reflect the ultimate land development and shall be used in all engineering calculations.

Operation and maintenance. A long-term operation and maintenance (O&M) plan must be developed and implemented to ensure that stormwater management systems function as designed. The long-term O&M plan shall include the following:

Stormwater management system owners;

Responsible parties for operation and maintenance, including how future property owners will be notified of the presence of the stormwater management system and the requirement for proper operation and maintenance;

The routine and nonroutine maintenance tasks to be undertaken after construction is complete and a schedule for implementing those tasks;

Plan that is drawn to scale and shows the location of all stormwater BMPs in each treatment train along with the discharge point;

Description and delineation of public safety features; and

Estimated operations and maintenance budget.

§ 381-51 Specific system design guidelines.

Bioretention design guidelines. Bioretention systems offer excellent pollutant removal, while providing some retention of stormwater runoff. Bioretention systems rely on the soil and planting media to remove pollutants and provide absorption of stormwater runoff. The following design standards should be followed to achieve the maximum benefit:

Construction components. Bioretention systems are constructed in an excavated hole and consist of, from bottom up:

Optional stone reservoir to provide additional holding capacity.

A minimum three-inch-thick transition layer of 3/8-inch pea gravel.

A layer of lightly compacted soil media at least 18 inches thick.

Vegetation consisting of dense plantings of woody shrubs, herbaceous perennials and, if the soil media is deep enough for the roots, small trees. The plants should be native if possible and must be both drought and flood tolerant.

A cover of three inches of aged, fibrous bark mulch.

(f)

A maximum six-inch depression for surface stormwater storage.

Soil media. The soil media shall have a maximum fines content of 5% and shall consist of:

Topsoil: 20% to 30%.

Organic materials (combination of woodchips/mulch and compost): 20% to 30%.

Sand: 50% to 55%.

Filter fabric. Filter fabric should not be used between the soil media and native soils or soil media and transition stone/stone reservoir. The use of fabric between these layers will cause system failure due to clogging from fines located within the soil media. If an underdrain is to be used to drain the bioretention area, then filter fabric can be used between the underdrain bedding and the native soils to prevent the migration of native soils into the underdrain bedding.

Naturalized basin design guidelines.

Naturalized basins have several advantages over traditional basins, including:

The deeper root systems of the native plant materials encourage infiltration, recharging groundwater tables and increasing base flows.

The plants trap pollutants, increasing the water quality of the discharge.

The vegetation serves to cool water temperatures and slow stormwater velocities.

They are visually more attractive and can help beautify a neighborhood, increasing property values.

They require less maintenance. Generally, annual mowing and periodic trimming of trees and plants is sufficient.

The following design standards shall be followed to achieve the maximum benefit:

The basin shall be easily accessible for maintenance.

Construct basin with a sediment forebay at the inlet, sized to hold a minimum of one year's worth of sediment accumulation if no other pretreatment is proposed.

Construct basin to have a natural low-flow channel with turf reinforcement material to remove pollutants and prevent erosion.

Incorporate a naturally landscaped area at the ground surface. The ground surface around the basin shall be large enough to be in scale with the overall landscaped area. The purpose is to filter and soften views from residential areas.

Plant all areas of the naturalized basin, including basin floors, side slopes, berms, impoundment structures, or other earth structures, with suitable vegetation such as naturalized meadow plantings or lawn grass specifically suited for stormwater basins. Suggested plants include:

Grasses: Big Bluestem, Switchgrass and wildflower mixes. In wet areas, plant Sweetflag and Soft Rush for color and texture.

Shrubs: Red Chokeberry (Aronia arbutifolia), Silky Dogwood (Cornus ammomum), Arrowwood (Viburnun Dentatum), Cranberrybush (Viburnum trilobum), service berry/shadbush (Amelanchier cavadensis or laevis) and elderberry (sambucus).

Trees: Red Maple (Acer rubrum), River Birch (Betula nigra), various willows.

(f)

Trees may not be planted below the pool area of the basin. If shrubs are used, they must be adapted to wet or moist soils conditions.

(g)

Mulch may be used in shrub beds located within the pool area with a non-floating-type mulch.

(h)

Group trees or shrubs to avoid a spotty effect.

(i)

Provide access to the basin for maintenance. Blend access area in with the surrounding landscape to the extent feasible.

(j)

The forebay/sediment trap shall be at least 10 feet long and sized to hold at least the annual sediment loading.

(k)

Maintenance access shall be planted with grass and at least 10 feet wide with a maximum slope of 15% and a maximum cross slope of 3%.

(l)

Provide a means to prevent soil compaction on the floor of the basin during construction.

(m)

Size treatment storage area to hold the water quality volume.

(n)

The perimeter of all basins shall be curvilinear so that from most edges of the basin, the whole basin will not be in view. A more traditionally shaped (oval or rectangular) basin may be permitted when conditions such as topography, parcel size, or other site conditions warrant. Basins shall follow natural landforms to the greatest extent possible or be shaped to mimic a naturally formed depression.

(o)

Place inlets and outlets to maximize the flow path through the facility. At a minimum, the flow path shall be twice as long as wide. Baffles, pond shaping or islands can be added within the permanent pool to increase the flow path. If there are multiple inlets, the length-to-width ratio shall be based on the average flow path length for all inlets.

(p)

Minimum one foot of freeboard above the twenty-five-year storm elevation.

(q)

The interior slopes of the basin within the pool area shall not exceed a slope of four horizontal to one vertical.

(r)

A minimum of six inches of topsoil with at least 6% organic content shall be provided for all planting ground cover beds or lawn areas.

(s)

Low-flow outlets shall be designed to prevent clogging.

(t)

For basins that cannot infiltrate the water quality volume, use a soil filter conforming to the following:

Impoundment depth: Peak storage depth within the filter area for water quality volume may not exceed 18 inches.

Pipe layout and spacing: Layout of the pipe underdrain system must be sufficient to effectively drain the entire filter area. There must be at least one line of underdrain pipe for every eight feet of the filter area's width. The slope of the pipe must be 1% or greater.

Pipe bedding: Minimum 12 inches over top of drainage pipe, six inches thick at sides, and six inches below drainage pipe of clean well-graded gravel.

[4]

Filter bed: The soil must consist of loamy, coarse sand. The soil filter must extend across the bottom of the entire filter area. The soil must be at least 18 inches deep and underlain by a gravel bedding.

[5]

Surface cover: The top of the underdrain system must be covered with a four-inch layer of sandy loam and then covered with plantings consisting of species tolerant of frequent inundation.

[6]

Underdrain outlet: Each system must discharge to an area capable of withstanding concentrated flows and saturated conditions without eroding.

Article XIII Parking and Loading Guidelines for Town Center Overlay District

[Adopted 5-1-2008; amended 2-18-2016]

§ 381-52 Authority; purpose; additional regulations.

Statutory provision: Code of the Town of Groton, § 218-30.2, as amended, and § 218-23, as amended.

Purpose. The purposes of these guidelines are broadly as follows:

To reduce the amount of area allocated to parking spaces while accommodating typical peak parking needs of the Town Center Overlay District.

To encourage and maximize the creation of a well-connected, parking, walking and bicycle access system throughout the Town Center Overlay District.

To enhance the environment of this area for its adjacent neighborhoods, Groton residents, workers, and visitors to the Town Center Overlay District.

To adequately accommodate the Town Center Overlay District's typical peak parking demands and its commercial loading and goods delivery requirements.

PUBLIC PARKING SUPPLY DEMAND REDUCTIONS

To avoid the creation of "overflow" parking demands from the Town Center Overlay District into the Town center's adjacent residential and commercial areas, whether on- or off-street.

Relationship to Code of the Town of Groton. Parking and loading in the Town Center Overlay District is governed by § 218-23 of the Code of the Town of Groton, in its entirety, and these Town Center Overlay District Parking and Loading Guidelines.

Implementation. In accordance with the purposes described above, all parking and loading in the Town Center Overlay District are hereby regulated and restricted by Code of the Town of Groton § 218-23, in its entirety, and as hereinafter provided.

§ 381-53 Definitions.

For the purposes of these guidelines, the following terms are defined for estimating necessary parking supply within the Town Center Overlay District:

This involves reducing the overall parking supply cited in § 218-23 by assuming that the future public on- and off-street parking supply created within the Town Center Overlay District will be shared by Town Center Overlay District land uses and recreational resources (i.e., the Nashua River Rail Trail) located within a convenient walking distance of the destinations of parkers.

SHARED PARKING DEMAND REDUCTIONS

This involves reducing overall parking requirements cited in § 218-23 of the Code of the Town of Groton by creating an agreement between affected property owners to share available parking spaces when those spaces are located within a convenient walking distance of the parker's destination. Such agreements can be applied when land uses having different parking demand patterns are able to use the same parking spaces and areas throughout the day and thereby reduce their combined demands. Shared parking is most effective when sharing land uses have significantly different peak parking characteristics that vary by time of day, day of week, and/or season of the year. In these situations, shared parking strategies will result in fewer total parking spaces needed when compared to the total number of parking spaces needed for each individual land use or business. Mixed land uses tending to benefit from specific shared parking arrangements include the Nashua River Rail Trail and the mixed uses being considered for the Town Center Overlay District. This also refers to parking demands that may be reduced at retail facilities because a proportion of patrons are expected to walk or bike to the Town Center Overlay District. For purposes of the Town Center Overlay District, land uses that may have parking reductions include office, institutional (i.e., Town Hall/Fire Department employees and visitors) and certain types of retail uses (i.e., coffee shops, small retail shops and Nashua River Rail Trail-oriented retail uses).

SHARED PARKING PLAN

This is a scaled plan (e.g., one inch equals 40 feet) delineating the parking areas that are to be shared under a shared use agreement.

SHARED USE AGREEMENT

This is a binding legal agreement by and between signatories representing land uses within the Town Center Overlay District to share the construction, maintenance, and liability for identified shared parking facilities within the Town Center Overlay District.

TOWN CENTER OVERLAY DISTRICT (TCOD)

That portion of the Town of Groton described and defined in § 218-30.2, as amended, of the Code of the Town of Groton.

§ 381-54 Performance requirements.

Adequate parking must be available in the Town Center Overlay District to service the typical net increase in peak parking demands.

Massachusetts General Law (MGL) Chapter 90, § 16A, Stopped Motor Vehicles; Operation of Engine; Time Limit Penalty, will be strictly enforced in the Town Center Overlay District. As a convenience to the reader, M.G.L. C. 60, § 16A, is quoted here: "No person shall cause, suffer, allow or permit the unnecessary operation of the engine of a motor vehicle while said vehicle is stopped for a foreseeable period of time in excess of five minutes. This section shall not apply to (a) vehicles being serviced, provided that operation of the engine is essential to the proper repair thereof, or (b) vehicles engaged in the delivery or acceptance of goods, wares, or merchandise for which engine assisted power is necessary and substitute alternate means cannot be made available, or (c) vehicles engaged in an operation for which the engine power is necessary for an associate power need other than movement and substitute alternate power means cannot be made available provided that such operation does not cause or contribute to a condition of air pollution. Whoever violates any provision of this section shall be punished by a fine of not more than one hundred dollars for the first offense, nor more than five hundred dollars for each succeeding offense."

§ 381-55 Number of spaces.

Standards for individual land uses set forth in § 218-23, as amended, will apply to land uses within the Town Center Overlay District that do not participate in a shared use agreement. If an alternative shared loading modification can be justified to the satisfaction of the Planning Board, the applicant may propose modifications of § 218-23, Off-Street Parking and Loading, requirements.

No parcel located in the Town Center Overlay District may count on-street parking spaces located within the Town Center Overlay District toward the number of spaces required by Code of the Town of Groton § 218-23.

§ 381-56 Application of shared or compact parking spaces and operating hours.

Retail, office, institutional, and residential applicants for new development within the Town Center Overlay District shall examine the feasibility of using shared parking arrangements to reduce the total required parking supply in the Town Center Overlay District.

Shared parking agreements shall reduce individual land use parking space requirements cited in § 218-23, usually less than 20%, including public on- and off-street public parking resources. The use of smaller/compact parking spaces (refer to § 218-23.1, Subsection K) shall be limited to 1/3 or fewer of the total shared parking supply. The application of shared parking to reduce the overall supply of parking in the Town Center Overlay District for certain land uses may necessitate strict adherence to temporal restrictions to keep peak demands from coinciding.

Where the Planning Board deems appropriate, signatories to a shared parking agreement shall be required to identify and adhere to temporal restrictions on operating hours associated with the land uses involved in the shared parking agreement.

§ 381-57 Calculation of parking spaces required with shared parking agreement.

The minimum number of parking spaces for a mixed-use development where shared parking is proposed shall be determined by a study prepared by the applicant following the procedures of the Urban Land Institute (ULI) Shared Parking Report (Second Edition, 2005) or the ITE Parking Generation Report (3rd Edition, 2004), ITE Shared Parking Guidelines (1996), or other resources that the Planning Board may find acceptable. A formal parking study may be waived for small developments where there is established experience with the land use mix or its impact is expected to be minimal. The actual number of proposed parking spaces shall be based on well-recognized sources of parking data, such as the ULI or ITE sources cited above or local parking usage surveys.

If the proposed shared parking plan assumes shared use of an existing parking facility, field surveys shall be conducted to determine the actual hour-by-hour use of the existing parking supply. If the shared parking plan assumes the shared use of a future public parking supply, assumptions regarding the peak use of the future parking supply with and without the shared parking plan in place shall be provided to the Planning Board.

The applicant shall determine the minimum number of parking spaces needed by a mixed-use development by following the following four-step procedure:

Step 1: Determine combined "stand alone" parking requirements under § 218-23 by individual land uses proposed within the shared parking arrangement.

Step 2: Estimate the peak "combined" parking demand weekday and weekend hours. Section 218-23 represents individual land use peak demand requirements. The applicant shall estimate the hourly distribution of its peak demands, typically using the 85th percentile demands as published in available resources such as the Urban Land Institute (ULI) Shared Parking report (as amended) and the Institute of Transportation Engineers (ITE) Parking Generation report (as amended) for retail, restaurant, office, and residential parking demands.

It is common that the residential parking supply may not necessarily be included in a shared parking agreement, but the Planning Board will not preclude residential shared parking resources.

The following four combined parking peaks should be assessed, with the worst-case parking space demands prevailing for estimating the peak "combined" parking demand requirements, including a "peak season" estimate, if applicable:

Typical weekday (Monday through Friday) mid-day parking demand peak;

Typical weekday (Monday through Friday) evening parking demand peak;

Typical weekend Saturday mid-day parking demand peak; and

[4]

Typical weekend Saturday evening parking demand peak.

Justifiable variations from nationally published peak parking demand rates will be considered by the Planning Board as long as the applicant provides the data for the differences compared to rates contained in industry standard resources, such as either of the two resources cited above, such that the Planning Board can make a determination as to which peak "combined" estimate should be employed as it pertains to the administration of this article. The Planning Board may require strict adherence to proposed operating hours by use which will run with the space. Changes in use may require a review of operating hours by the Planning Board to ensure the performance requirements of this article are achieved.

Step 3: Determine the availability of public parking resources for serving the peak "combined" parking demand under a shared parking agreement. Public parking within the Town Center Overlay District consists of two components: on-street parking and off-street parking. The exact number of off-street public parking supply within the Town Center Overlay District to be considered under Step 3 is highly dependent upon Town decisions concerning land adjacent to the Rail Trail and the ultimate disposition of a privately owned parcel of land behind Town Hall. On-street parking within the Town Center Overlay District may not be counted toward the number of parking spaces required by Code of the Town of Groton § 218-23. The estimate of the available public parking supply shall be coordinated with the Planning Board at the time the application is submitted. Allocation of the available public supply shall be estimated based on the proportion of land within the overall Town Center Overlay District being considered for a shared parking agreement.

Step 4: Compile a shared parking plan summary. After determining the peak parking demand and the component of public parking resources expected to be available during the peak "combined" parking demand period, essentially, the minimum requirement at the maximum demand across all periods, the applicant shall compile a shared parking plan summary that identifies the total number of spaces that would be needed under § 218-23 by use, the total number of parking spaces that will be constructed by the applicant, and the proposed spaces assumed to be shared through the public parking supply.

The shared parking plan summary is to be submitted to the Planning Board for review and concurrence. While mindful of the need to ensure adequate parking for users of the Rail Trail, at its discretion, the Planning Board may accept a significant reduction in the "stand alone" parking requirement, usually less than 20%, and may require the saved space to be dedicated to such uses as open green space or bicycle storage facilities.

§ 381-58 Distance to parking spaces, pedestrian and bicycle connection and facilities requirements.

The closer shared parking spaces are to the land uses they serve, the more likely the arrangement will be a success. Shared spaces for residential units, if to be included in the shared parking arrangement, must be located within a three-hundred-foot radius of the dwelling unit entrances they serve. Shared parking spaces for other uses should be located within a five-hundred-foot radius of the principal building entrances of all sharing uses. Up to 20% of the shared parking spaces for nonresidential uses may be located between a five-hundred-foot radius and a one-thousand-foot radius from the principal entrances.

Clear, safe, Massachusetts Architectural Access Board/Americans with Disabilities Act-compliant sidewalks and pedestrian access as direct as possible must be provided between the building entrances and the shared parking spaces.

Similarly, the provision of convenient and secure bicycle storage facilities close to the well-used entrances of Town Center Overlay District buildings, with signage, markings, and possibly shower facilities for cyclists should be incorporated in the design of the Town Center Overlay District developments. Proper maintenance of the bicycle parking facilities required shall be a continuing obligation of the property owner. The following summarizes bicycle parking requirements within the SAOD:

Residential: Two spaces per dwelling unit or two interior storage devices per unit.

Retail businesses and offices: Four spaces per business or two spaces per 1,000 square feet, whichever is greater.

Optionally, an applicant may also contribute additional bicycle parking spaces (gift under M.G.L. C. 44, § 53A) and/or bicycle parking equipment to the Town for the Nashua River Rail Trail (NRRT) bicycle parking supply. The Town, in coordination with the Department of Conservation and Recreation (DCR) which has jurisdiction over the NRRT, will determine the location of all contributed bicycle parking spaces and the placement of contributed bicycle parking equipment.

§ 381-59 Shared parking plan and agreement.

A model shared parking agreement form is attached (see Appendix A).[1] Provisions for funding future maintenance of shared parking spaces shall be clearly identified in the agreement to ensure that routine maintenance (e.g., striping, potholes, etc.) is addressed in a timely manner.

Editor's Note: A model agreement is included as an attachment to this chapter.

The shared parking agreement shall include a shared parking plan with the following elements:

A scaled plan at one inch equals 40 feet of the entire shared parking spaces layout prepared by an architect or engineer registered in the Commonwealth of Massachusetts showing the location and types of shared parking spaces and their proximity to the uses they will serve. The plan should also show the location and proposed percentage of small and regular parking spaces in accordance with § 381-60 below, as well as accessible spaces in accordance with Massachusetts Architectural Access Board Regulations, 521 CMR, and the Americans with Disabilities Act MAAB/ADA requirements. The location of assumed on-street parking spaces, while not included in the shared parking total, shall be shown on the plan.

If applicable, the location of trail-blazing signage that directs drivers to the most convenient and compact vehicle parking areas for each particular use or group of users.

If applicable, highlight the location of public and shared parking spaces assumed to be subject to regulation (e.g., no overnight parking in nonresidential shared parking spaces; possible one- or two-hour parking for certain on-street spaces in front of retail establishments).

Specific pedestrian and bicycle circulation features illustrating the connections and walkways between parking areas and land uses, as well as those buildings that will include cyclist-friendly facilities such as showers or lockers. Pedestrian paths should be as direct and short as possible. Exclusive bikeways (i.e., the Nashua River Rail Trail) and other specific features encouraging bicycle use or walking such as the location and quantity of bicycle storage facilities should be highlighted.

Safety and security features such as lighting and the maintenance plan for parking areas, including snow removal, disposal, and routine maintenance.