3.04:   Design Standards

1. Purpose. Purpose. 974 CMR 3.04 sets forth the Design Standards that apply to parking, stormwater management practices (SMPs), setbacks, screening, topographic and vegetative alterations, site improvements (sidewalks, curbing, and lighting), utility connections, and landscape treatment. There are special requirements for certain Zoning Districts.

2. Setback Requirements.
   (a) For all lots in all zoning districts, the minimum setbacks of structures from lot lines shall be as follows:
   side: 10 feet

   rear: 25 feet

   front: 25 feet (except in the Innovation and Technology Center District where the minimum front setback is 15 feet).

   (b) For lots abutting or containing zoning district boundary lines, setbacks shall be increased to 25 feet, unless adjacent to the Residential I and Residential II zoning districts where the minimum setback shall be 50 feet.

   (c) The minimum setbacks for accessory buildings in residential districts shall be 5 feet from a side or rear lot line.

   (d) Environmental Business District. Setbacks shall comply with the requirements of all districts, except the minimum side and rear setbacks for lots abutting Walker Road in the town of Shirley shall be one hundred and fifty (150) feet in addition to the public open space buffer parallel to Walker Road.

3. Parking.
   
   (a)   All Districts.
   1. Dimensional and Related Requirements.
      a. In all districts, except where buildings are set back 150 feet or more in the Rail, Industrial, and Trade Related District (see below), principal parking lots shall be located to the rear and sides of the buildings with only visitor, handicapped, and preferential parking situated within the front setback. Preferential parking includes spaces for carpools, vanpools, and other ridesharing vehicles. Parking allowed in the front of the building shall be limited to 10% of the total parking spaces to be built. The principal parking serving the site shall not intrude frontward of the building facade (including major architectural appurtenances).

      In cases where buildings in the Rail, Industrial, and Trade Related District are set back 150 feet or more, parking is permitted in the front of the building. In such instances, a landscaped strip between the front lot line and the parking lot, measuring at least 60 feet deep, shall be provided.

      b.   Parking spaces shall be at least nine (9) feet wide by eighteen (18) feet deep. Aisle widths shall be at least twenty-four (24) feet. All parking lots shall conform to Article XIV of the By-Laws. Handicapped spaces (dimensions, locations, and so forth) shall conform to the Massachusetts Architectural Access Board (521 CMR).

      The number of designated handicapped parking spaces is based on the total number of spaces required. Handicapped parking spaces may be constructed in phases or reserved, although an adequate number shall be constructed with the initial phase. Additional handicapped spaces shall be constructed when the reserve or phased parking is constructed.

      Total parking spaces	Required handicapped spaces
      15 to 25 spaces	1 designated space
      26 to 40 spaces	5%, but not less than 2
      41 to 100 spaces	4%, but not less than 3
      101 to 200 spaces	3%, but not less than 4
      201 to 500 spaces	2%, but not less than 6
      501 to 13,000 spaces	1.5%, not less than 10

      c. No parking facility shall be used for servicing or repair of vehicles or the storage or display of merchandise or other objects that otherwise interfere with its availability for parking.

      d. Landscape islands shall serve a functional purpose for stormwater infiltration and evapotranspiration, and should be used whenever possible to reduce runoff, increase groundwater recharge, and increase screening and shade with trees. Parking lots shall extend no more than 180 feet in either length or width without a landscaped area. The landscape areas shall be an 18-foot minimum width along intermediate islands, and a ten-foot minimum width for terminal islands and divider islands (see 974 CMR 3.06(2) Figure B). Parking lots measuring less than 180 feet in either length or width shall be divided into bays not greater than 72 feet in length by terminal or intermediate island (see 974 CMR 3.06(2) Figure B). Terminal islands shall be ten feet in minimum width and intermediate islands shall be 18 feet minimum in width. In truck parking lots, the Applicant may consolidate intermediate islands, to allow 360’ between intermediate islands, with intermediate islands constructed at 36’ minimum width. Divider islands in truck parking areas shall be a minimum of twenty feet deep.

      e. The number of parking spaces constructed may not exceed the number of spaces required by the Massachusetts Architectural Access Board and ADA plus those required by the By-Laws and Exhibit C therein. Except in the Innovation and Technology Center Zoning District, on-street parking is only permitted where approved by the DEC and consented to by MassDevelopment.

      f. There shall be bicycle storage facilities provided on site.

   2. Construction Standards:
      a.   Parking lots, loading dock areas, and driveways shall be constructed of bituminous concrete pavement. The construction specifications shall be the following:
      1. Compacted subgrade, free of frost, roots, and debris.

      2. Eight inches of compacted gravel sub-base conforming to Massachusetts Highway Department Standard Specifications for Highways and Bridges (MHDSSHB) M.1.03.0 Type A.

      3. Four inches of compacted gravel base conforming to MHDSSHB M.1.03.0 Type B.

      4. Two inches of bituminous concrete binder course.

      5. 1½ inches of bituminous concrete top course

      b. The portion of the parking lots, loading docks, and driveway subject to truck traffic, truck and container storage, and other railroad related vehicles, shall be constructed of bituminous concrete pavement. The construction specifications shall be the following:
      1. Compacted subgrade, free of frost, roots, and debris.

      2. Eight inches of compacted gravel subbase conforming to Massachusetts Highway Department Standard Specifications for Highway and Bridges (MHDSSHB) M.1.03.0 Type A.

      3. Four inches of compacted gravel base conforming to MHDSSHB M.1.03.0 Type B.

      4. Three inches of bituminous concrete base course.

      5. 1½ inches of bituminous concrete binder course.

      6. 1½ inches of bituminous concrete top course.

      c. The Applicant may propose modifications to the pavement construction specification where anticipated traffic and usage justify a lesser standard. Modified pavement design calculations (including load bearing data of the pavement and underlying soil) and construction specifications shall be reviewed and approved by the DEC. Any remaining parking and driveway areas shall be constructed in accordance with 974 CMR 3.00. The Applicant shall provide the DEC gravel sieve analyses, compaction tests, and pavement slips during construction activities. The Applicant is also required to allow the Director or designated representative to monitor all paving activities to confirm compliance with the approved pavement modification. The Applicant shall pay for all consultant costs associated with construction inspections and monitoring.

      d.   Parking spaces and striping shall be painted according to the MHDSSHB. Lines shall be located along the sides and unless curbing is present, at the head of parking stalls. Lines shall be a minimum of four inches wide and shall be one consistent color, either reflective yellow or reflective white paint.

      e. Parking lots measuring less than 10,000 square feet in area are encouraged to utilize an open drainage system to minimize the depth of detention/retention basins, reduce maintenance, and decrease construction costs. Parking lots subject to truck traffic, truck and container storage, and other related vehicles must utilize a pretreatment practice such as a biofiltration basin to remove metals, hydrocarbons, and associated pollutants if open drainage is used.

   3. Landscape Treatments. Landscape Treatment around the perimeter and interior to the parking lot is required and shall be used to manage stormwater as well, to the extent feasible; landscape treatments may also be required to screen parking lots or elements of parking lots (such as dumpsters or loading docks). Parking lots shall be landscaped in accordance with 974 CMR 3.04 (8).

   4. Driveways/Curb Cut Locations.
      a. Any portion of any entrance or exit driveway shall not be located closer than 150 feet to the curb/gutter line of an intersecting street.

      b. The driveway entrance radii curves shall be designed to accommodate the turning radii of the vehicles using the entrance.

      c. There shall be a distance of at least 40 feet between any two driveways measured at their intersections with the street.

      d. Driveway widths shall be not less than 24 feet for a two-way driveway and 14 feet for a one-way driveway.

      e. Intersection sight distances shall be provided in accordance with current AASHTO guidelines for prevailing (85th percentile) speeds on adjacent ways to ensure adequate safety.

      f. Common driveways are encouraged in order to minimize curb cuts, reduce paving costs, and lower impervious coverage. The Applicant shall submit evidence that separate property owners have the legal right to use the common driveway. The DEC may disapprove a common driveway if it determines that the facilities will generate volumes of traffic that would require separate driveways or that the traffic generated from the individual sites cannot be safely combined.

      g. A standard "STOP" shall be installed at the intersections of driveways with public streets.

   5. Fire Equipment Access. Access to buildings shall be kept clear of hazardous substances and obstacles that may, in the opinion of the fire officials, impede the proper placement of fire apparatus and personnel in case of emergency. The applicant shall obtain a letter from the Devens Fire Chief stating there is adequate access for fire equipment. Access for fire equipment shall be provided and maintained on at least two sides of the building. Fire lanes shall be designated with pavement marking and signage.

   6. Parking Lot Phasing. If an applicant proposes parking lot construction phasing, the applicant shall demonstrate that the portion to be constructed is sufficient for the needs of the users of the proposed structure. The unconstructed parking area shall be large enough for anticipated needs and shall be shown in a contrasting graphic pattern delineated on the Site Plan. The Parking Lot Phasing plan shall address erosion and sediment controls before and during construction, and specifically cite measures to be implemented to minimize soil compaction in areas not to be paved until later phases. Surety or other adequate performance assurance to construct the lot at a specified time in the future. The DEC may then approve the parking lot phasing if it determines sufficient parking will be provided for current needs and adequate assurance exists to construct the remaining parking area when needed.

   7. Common Parking Facilities. Parking facilities shared between two or more users are encouraged in all zoning districts to minimize excessive paving and the size and number of areas devoted to parking. Common (i.e. “public”) parking facilities are allowed in all districts except the Open Space/Recreation district.

   (b)   Viewshed Overlay District. Parking lots in the Viewshed Overlay District shall be located on the far side of the building from the viewshed sensitive receptor and/or along the sides of the building (see 974 CMR 3.06(3) Figure C). Parking lots shall not be located between the building and the viewshed sensitive receptor except for a maximum of 10% of the total parking spaces constructed which may be located between the principle building and the street that provides the frontage.

   (c)   Historic Overlay District. The applicant shall demonstrate the feasibility of shared use of parking lots or the creation of common parking facilities has been investigated. If the investigation demonstrates feasibility, the applicant shall present a plan to the DEC indicating a parking and access easement for shared use of parking lots with the abutter(s). The applicant shall provide evidence that an agreement has been made with the abutter and that the easement has been recorded at the Registry of Deeds.

4. Stormwater Management.
   (a)   General Provisions.
   1. Overview. Stormwater Management in Site Plan review generally consists of managing stormwater on the site. Stormwater may be retained and recharged on-site, removed by evapotranspiration, or connected to the public drainage system.

   2. Fundamentally, the DEC encourages Applicants to consider the site’s location, abutting and on-site natural resources, and topographic characteristics. The applicant shall identify what resources need to be protected, the anticipated uses and use intensities, and propose an economic, protective, and efficient stormwater management system.

   3. All Site Plan Submissions shall design the stormwater management system in compliance with the Massachusetts Department of Environmental Protection Stormwater Management Policy (DEP SMP) as most recently amended to the greatest extent possible given the specific site constraints of each site. The Applicant shall submit a completed Stormwater Management Form (SMF), stamped and signed by the Engineer that designed the system, that indicates compliance with Stormwater Management Standards. The applicant shall also provide calculations demonstrating compliance with each standard.

   4. Stormwater Management design shall be incorporated into the site planning to allow for the full utilization of the property while maintaining the pre-development characteristics of the site as though it were a “green field” (volume, frequency, peak runoff rate) to the greatest extent possible. Maximizing the use of pervious areas minimizes stormwater runoff from a site, improves stormwater quality, and increases groundwater recharge. Maintenance of these on-site stormwater management systems must be incorporated into facility operations, and is generally the responsibility of the landowner.

   5. Drainage systems shall follow the requirements of the Devens Stormwater Pollution Prevention Plan, the Water Resources Protection Report, and the Water Resources Protection By-Law. For requirements, design standards, and criteria of stormwater management systems, refer to 974 CMR 4.08.

   6. Regardless of whether site drainage is handled on-site or conveyed to a common or public stormwater management system, on-site stormwater management recharge systems shall be used for roof runoff (excluding metal roofs), whenever practicable.

   (b) Stormwater Management options for Site Plan Submissions: Site generated stormwater may be managed on-site, conveyed to a common system (operated by the owners of more than one lot), or conveyed to the Devens Stormwater System (DSS), managed by MassDevelopment.

   1. For lots served by the Devens Stormwater System (DSS), the applicant may connect site drainage to the DSS without on-site detention provided that the following standards are achieved:
      a. The applicant shall obtain written approval from MassDevelopment/Devens Engineering stating that the DSS can accommodate the anticipated peak rate of runoff for the 25-year storm event using the Natural Resources Conservation Service (NRCS) TR-55 method and that the DSS basins have adequate capacity to accommodate the 100-year storm event (TR-20 Methodology).

      b. A Stormwater Pollution Prevention Plan for all disturbed areas, as defined in the Devens Stormwater Pollution Prevention Plan, shall be included.

      c. An adequate system for collecting on-site stormwater has been designed for the premises.

      d. There shall be no negative impact from drainage on abutting properties, nor any negative impact to any public or private water supply or designated potential future supply.

   2. On-site stormwater management systems for areas without access to the DSS shall include: Conveyance Structures, Detention Basins, Extended Detention Basins, Retention Basins, swales and infiltration structures, and water harvesting devices. There are an increasing number of on-site SMPs which effectively mimic natural hydrologic conditions. These general categories are not mutually exclusive and shall be combined where appropriate as current BMP’s. Drainage calculations shall be prepared by the Applicant's Engineer, including design criteria, pre- and post-drainage areas and other information sufficient for the DEC to verify the size of the proposed drain, swale, drain field, culvert, bridge or catch basin. Said calculations shall be made separately for each drainage facility, showing its location, the drainage catchment areas and subareas, the underlying soil types and the flow paths for the times of concentration, the design run-off, facility size, slope and capacity and velocity of water through it.

   3. All closed drainage systems subject to heavy truck traffic, truck and container storage, and railroad related vehicles shall flow through an oil/water separator capable of removing 75% total suspended solids (TSS) before discharging into a swale, detention system, extended detention system or the DSS.

   (c) Monitoring and Maintenance of Stormwater Facilities. The applicant shall agree to comply with a monitoring and maintenance schedule as follows:
   (a) Monthly inspection for and repair/cleaning of damaged or clogged catch basin grates.

   (b) Biannual inspection of detention/retention basins and swales for erosion, debris, sand deposits, and vegetative growth. Vegetation shall be cut back annually, as appropriate, and debris or sediment removed from these areas.

   (c) Biannual sweeping of the parking lots.

   (d) Biannual cleaning of catch basins.

   (e) Submission of an annual report to the DEC by the end of February for the previous calendar year indicating maintenance issues have been adequately addressed and corrective measures were made where necessary.

   (f) The Site Plan shall specify the construction and post development Maintenance Schedule in detail on the Utility Plan. This will ensure that all parties understand and are aware that a Maintenance Plan exists.

5. Topographic Alterations.
   (a) Topographic alterations shall be minimized to the greatest extent possible, such that buildings, roadways, parking, detention/retention facilities, and all other site improvements shall be located first in previously developed, cleared, disturbed, and/or improved areas of the site, before requiring topographic alterations in previously undisturbed or vegetated areas.

   (b)  Topographic alterations in undeveloped woodland areas within the setbacks may be approved by the DEC if it determines that the construction of earth berms or slopes will reduce any adverse impacts of development. Tree removal shall be allowed in undeveloped woodland within the setbacks to create a berm or other topographic alteration, so long as alterations are minimized. Replication of trees may be required by the DEC using the same standards established in 974 CMR 3.04 (8) (d) 8.

   (c) Topographic alterations may be allowed to provide Improvements to the lot if no other access point can be made safely through already disturbed frontage or if all frontage is undisturbed, such that alterations are to the minimum extent necessary to construct the infrastructure.

   (d) Earth removal shall comply with the By-Laws and 974 CMR 4.07.

6. Site Improvements

   (a)   All Districts.

   1. Sidewalks/Walkways: Sidewalks and pedestrian walkways shall conform to the Massachusetts Architectural Access Board (521 CMR) requirements, as amended.
      a.   Pedestrian walkways shall be separated from roadways constructed with sloped curbs or Cape Cod Berms by a landscape strip at least three feet wide.

      b.   Pedestrian walkways may be adjacent to a roadway that is constructed with a vertical curb separating the roadway from the walkway.

      c.   Principle building entries shall have an accessible pedestrian walkway connecting to pedestrian walkways within the abutting public rights-of-way.

      d.   If pedestrian paved areas, such as a plaza, are larger than a 20-foot square, pavement shall be conventional cement concrete modified to make it darker and to reduce the reflectivity of the materials. Unit pavers, brick, or stone of dark color and limited reflectivity are acceptable.

   2. Trails - When a portion of the public trail system as shown on the Devens Main Post Trails report dated July 2001 and any amendments thereto adopted by the DEC falls within the lot to be developed, the trail shall be constructed and an appropriate that portion of the trail on the lot. The trail detail is shown as 974 CMR 3.06 (12) Figure L. or as approved by the DEC.

   3. Curbing.
      a.   Sloped granite curb, vertical granite curb and Cape Cod berm are allowed. Vertical granite curb is required at all driveway entrance roundings to the point of rounding tangency. Cast-in-place monolithic, reinforced, air-entrained concrete vertical curb and sidewalks or vertical granite curb is required where sidewalks abut driveways or parking areas.

      b.   Vertical granite curb, where provided, shall be Type VA4 as specified in Section M9.04.1 of the Massachusetts Highway Department Standard Specifications For Highways and Bridges (MHDSSHB) with a six-inch reveal, as most recently amended. Granite transition stones shall be installed when vertical granite curb changes profile to sloped granite curbing or Cape Cod berm or where curbing transitions to areas with no curbs.

      c.   Sloped granite edgestone, where provided, shall be Type SA, SB, or SC as specified in Section M9.04.2 of the MHDSSHB with a six-inch reveal, as most recently amended.

      d.   Catch basins shall have curb inlet stones with transition stones when sloped granite edgestone or Cape Cod berm is used.

      e.   Cape Cod Berm, where provided, shall be a Modified Bituminous Concrete Berm - Type A (one foot width) as specified in the specified Section 106.1.0 of the Construction Standards of the MHDSSHB, as most recently amended.

      f.   Cast-in-place monolithic, reinforced, air-entrained concrete vertical curb and sidewalks shall conform to Section M4.0200 of the MHDSSHB for 4000 psi concrete.

   4. Lighting. Lighting shall conform to the Industrial Performance Standards, as most recently amended. Lighting posts, fixtires, and housing shall be uniform dark earthtone colors.
      a. Access Road/Parking shall be 0.5-foot candles minimum (maintained), with 30-foot maximum height posts.

      b. Walkway lighting shall be 1.0-foot candles minimum (maintained), with 15- to 18-foot high posts.

      c. All lighting shall be metal halide.

      d. Bollard lights shall have roof optics with 100% sharp cut-off or shall have, at a minimum, louvered lenses, providing maximum cut-off and be of a single dark earth-toned color.

      e. Site lighting plan shall indicate location of proposed/existing trees to demonstrate that there is no conflict between proposed lights and proposed/existing trees within the site.

      f. Lights may only be illuminated between 11 p.m. and 7 a.m. if the DEC determines lights are needed to ensure safety for night operations on the premises.

   5. Service Areas, Dumpsters, and Open Storage
      a. To the extent possible, service areas, dumpsters, or open storage areas shall be located to the rear of buildings.

      b. Service areas, dumpsters, or open storage areas shall not be located forward of the front facade of the building.

      c. Open Storage areas shall be designated on site plans. No open or exterior storage is permitted in undesignated locations.

   6. Loading docks shall be located to the sides and rear of buildings and shall not be located forward of the front facade of the building.

   (b)   Historic Overlay District: All development shall comply with the Regulations for historic districts. Applicants shall also consult the Devens Massachusetts Historical Commission Policy, in accordance with the programmatic agreement between the Army, the National Advisory Council on Historic Preservation, and the Massachusetts Historical Commission.

   Site improvements shall comply with the requirements of all districts, except as noted:

   1. Sidewalks/Walkways. Brick paving with hand-tight joints (no mortared joints) or an asphalt-setting bed with bituminous or concrete sub-base. No more than 20% of a pedestrian paved area larger than a 20-foot square may be conventional cement concrete.

   2. Curbing. Sloped granite edgestone shall be Type SA, SB, or SC as specified in Section M9.04.2 of the MHDSSHB as most recently amended with a six-inch reveal.

      Cape Cod Berm shall be a Modified Bituminous Concrete Berm - Type A (one foot width) as specified in the specified Section 106.1.0 of the Construction Standards of the MHDSSHB, as most recently amended.

      Cast-in-place monolithic, reinforced, air-entrained concrete vertical curb and sidewalks shall conform to section M4.02.00 of the MHDSSHB for 4000 psi concrete.

   3.  Lighting. Lighting fixtures and poles shall comply with the Report: Street Lighting Recommendation for Devens Historic Overlay District prepared by Carol R. Johnson and Associates of Boston, MA dated November 30, 2001. The DEC may allow alternatives within the interior of parking lots and in service areas. Alternative poles shall be a 30-foot maximum height with arm-type fixture, upward cutoff, and dark in color (post and housing), and shall be a style that is compatible and harmonious with the historic poles and the goals and objectives of the historic district as stated in Article X of the By-Laws.

7. Utilities.
   (a)   Sewage Disposal.
   1. All sewage generated by site development at Devens shall connect to the Devens public sewer system. The applicant shall provide evidence that the sewage generated by the proposed development shall be accepted by the DWWTF.

   2. Septic system construction is prohibited. Where a building is served by an existing septic system, the applicant may continue to use on-site sewage disposal only if two conditions are met:
      a.   Connection to the public system is so impractical as to constitute an extreme hardship; and

      b.   The upgraded or replaced system meets the 310 CMR 15.00 requirements.

   (b) Water Systems. Connection with the Devens water system is required for sanitary and fire suppression purposes. On-site wells may be used for irrigation or process water purposes with the approval of the DEC.

   (c) Utility Extensions. The DEC may require easements to allow utilities be extended to the undeveloped land abutting the site to allow for future connection with the public systems.

   (d) Other Utilities. All proposed and existing public and private utility connections, extensions, and services shall be located or relocated underground.

8. Landscape Treatment
   (a) The existing landscape of Devens is diverse, containing natural wooded environments such as the Nashua River corridor, Mirror Lake, and Robbins Pond, as well as open meadows and ceremonial landscapes such as the parade ground and the cemetery. New development shall be respectful and sensitive to the dominant landscape character of the site and Devens as a whole.

   (b) The purposes of Landscape Treatment Design Standards in Devens are to:

   1. Preserve and enhance the character of the Devens landscape.
   2. Provide attractive settings for new development.
   3. Preserve the character of the abutting towns of Shirley, Ayer, Lancaster, and Harvard.
   4. Preserve and enhance local and regional open space resources such as the Oxbow National Wildlife Refuge.
   5. Preserve the integrity of valuable regional historic resources, such as the Devens Historic District and the Fruitlands Museum.
   6. Support and encourage the use of sustainable design principles and operating practices that preserve and enhance wildlife habitats, water quality, and overall health of the natural environment.
   7. Encourage the use of indigenous plant material to provide natural habitat and food sources for wildlife and to maintain ecological diversity.
   8. Maintain high standards for active and passive recreation, conservation, and other public spaces in Devens and enhance property values for present and future development.

   (c) General requirements:
   1. All required landscape treatments shall be located entirely within the lot.
   2. Native plants shall be used in appropriate locations, such that individual plants are selected for their ability to thrive in or adapt to the particular soil and light conditions they are placed in. (For a list of recommended native plants, see Appendix A, List I).
   3. Under no circumstances, shall any plants be used that are recognized by the horticulture or agricultural industries as invasive, whether native or exotic (non-native). (For a list of known invasive plants, see Appendix A, List IV.).
   4. All plant material shall meet all American National Standards Institute (ANSI) standards for plant material as set forth in Z60.1: American Standard for Nursery Stock, latest edition published by the American Association of Nurseryman. All plant material shall also meet certain standards of quality for form, structure, and health and have a minimum winter hardiness for Zone 5B, as determined by the American Standards for Nursery Stock.
   5. Minimum sizes for plant material, unless indicated elsewhere in this Regulation, shall be as follow:
      a.  Deciduous shade trees: three-inch caliper,

      b. Deciduous ornamental trees: two-inch caliper, and

      c. Evergreen trees: six-foot height

      d. Shrubs. For screening in car parking areas, three-foot height; for other screening purposes (dumpsters, loading docks, etc.) six feet; any other purposes, 18 inches.

   6. Landscape Treatments shall be laid out in informal drifts rather than formal rows and shall undulate with site topography. Individual clusters of trees or islands of shrub beds are acceptable as long as the tree clusters and/or shrub islands overlap. Linear solutions shall be avoided wherever possible, unless the existing landscape treatment is so arranged.
   7. The applicant may request that the DEC determine that existing vegetation is suitably located, sufficiently visually impervious, and vigorous enough to be substituted for material required by these Regulations.
   8. Plant material located within 20’ of any road or other paved area shall consist of species recognized by the nursery, horticulture and botanical industries as being tolerant of roadway deicing salts. (For a list of some plants recognized as tolerant of roadway deicing salts, see Appendix A, List II.).
   9. In Village Growth I and II, the Innovation & Technology Center, Business/Community Services, and within the Historic District Overlay Zoning Districts, trees may be located in near-urban conditions, near sidewalks or in plazas. In these cases, the applicant shall propose trees that will tolerate or adapt to those conditions. (For a list of some plants that withstand urban conditions, see Appendix A, List III.).
   10. Landscaping shall be maintained in good condition.

   (d) Preservation of Existing Vegetation [See also CMR 3.04(5)]
   1. Buildings, parking, loading docks, access roads, and other site elements shall be sited to preserve existing healthy mature vegetation and maintain natural topography to the maximum extent feasible.

   2. All trees with a minimum 12” caliper within the setback shall be preserved. Healthy existing wooded areas within setback areas where buildings cannot be constructed shall be preserved to the greatest extent feasible.

   3. The Applicant shall not propose topographic alteration within the root zone of any existing tree or wooded area designated as preferably preserved.

   4. All work within the root zone of existing trees to be preserved shall be carried out under the direction and supervision of a certified arborist. The arborist shall be a professional Certified Arborist with a minimum of five years experience, who has successfully completed a certification program equal to the following: Massachusetts Certified Arborist (MCA) program examination sponsored by the Massachusetts Arborist Association, Wellesley, MA 02181-7913; Tel: (617) 431-1625. Should there be no feasible alternative, excavation for walkways, curbs, structures, and utilities within the root zones of preferably preserved trees shall be considered, and if allowed, shall at a minimum require hand excavation until roots are encountered, bending smaller main roots out of the excavation area, and sawcutting all roots over 1” caliper. All exposed ends of sawcut roots shall be kept moist by covering the exposed ends with wet peat moss and burlap until excavation is backfilled. Existing trees that have had excavation or grade changes within their root zone shall receive crown pruning and root fertilization per the arborist’s recommendations.

   5. When wooded areas have been cleared to create development sites, the applicant shall preserve the understory of the woodland, particularly towards the edges of the preserved areas. Native shrubs shall be planted along the edges of the preserved wooded area as needed to transition from lawn and development areas to wooded areas.

   6. Building structures, roadways, and paved areas shall be set back at least 12” from the drip-line of wooded areas and trees slated for preservation.

   7. Construction activities and site alterations shall not disturb the root zone of the trees designated for preservation. During construction, the applicant shall install and maintain tree protection fencing, or other protective measures approved by the Director, located 12” beyond the drip-line of the trees to be protected.

   8. The applicant shall be responsible to replace any trees designated to remain, which have been damaged, killed, or removed as a result of construction activities. The DEC requires replacement-in-kind, per caliper inch of deciduous trees and by height for evergreens. Two-inch caliper deciduous trees and four feet tall evergreens shall be the minimum size used for replacement. For example, if a 24” caliper deciduous tree is damaged or killed during construction, the applicant shall replace the tree with six 4" caliper trees, or any other combination adding up to 24 caliper inches. A 36 foot tall evergreen, for example, shall be replaced with six 6’ tall evergreens, or any other combination adding up to 36 feet.

   (e) Soil testing. In order to select plant material that is appropriate for the climate, soil type, light, exposure, and gradient of the site, the applicant shall have the existing soil tested for both mechanical sieve and chemical analyses by an independent testing laboratory, such as an agricultural extension service or a local agricultural college. The sieve analysis shall be based on the USDA Classification System. The chemical analysis shall be according to the standards of the Association of Official Analytical Chemists. Should additional soil be required to be used, such as topsoil or planting mix, the new soil shall be tested in the same manner. The testing results shall include recommendations from the testing agency on what amendments, if any, may be needed for the soil to support the proposed plant material in a healthy and vigorous condition and whether the soil can support lawn or woody plants. The Applicant may include these soils tests within the Submission, or shall indicate within the Submission that such soils tests will be performed during the construction process prior to the use of any on-site or imported loam or topsoil. Submission to the DEC of construction phase soil tests and recommendations shall be made a condition of the Permit.

   (f) Groundplane Treatment.

   1. All planted areas and “maintained’ lawns shall pitch at 1:50 minimum slope, to ensure positive drainage on planted areas. Certain alternative groundplane treatments, such as native meadow grasses and wildflowers, may have a minimum slope of 1:100, particularly if the area is used for groundwater recharge or surface water treatment. “Maintained” lawns are those which are cut frequently, once or twice a week during the growing season.

   2. All unpaved areas with a gradient between 1:50 and 1:3 shall receive lawn planting as a minimum. Grass shall be provided using either sod, seed, or hydroseed methods, or a combination thereof. The Applicant is encouraged to limit manicured lawn areas to those immediately surrounding buildings, roads and parking lots. In all other areas, the Applicant is encouraged to propose alternative groundplane treatments such as native meadow grasses and wildflowers (For a list of native meadow grasses and wildflowers, see Appendix A, List I.).

   3. Any unpaved areas steeper than 1:3 shall be planted with shrubs or groundcover having fibrous root systems.

   4. Any unpaved groundplane visible from a public way, residences, the Open Space Zoning District, or the principal entrance of buildings on abutting lots and at a gradient of 1:1.5 to 1:1 shall be stabilized using bioengineering methods of erosion control, and 100% plant cover. Riprap or trap rock shall not be used control erosion in these locations.

   5. No slopes shall be steeper than 1:1. Where space is limited, or the grade changes near preserved trees, the applicant shall provide retaining walls to avoid slopes steeper than 1:1. Retaining walls shall be fieldstone, fieldstone-veneer and capstones on concrete retaining wall, or flat-face interlocking concrete masonry systems with split-face texture.

   (g) Screening
   1. Screening shall be a year-round visually impermeable barrier that may be either existing, constructed, or a combination thereof.
      i. Existing screens may consist of natural topographic landforms, rock outcrops, or vegetation that is dense enough to be visually impermeable. ii. Constructed screens may consist of built screens, such as solid walls or fences, topographic screens, such as berms or landforms, vegetative screens consisting entirely of evergreen material, or a combination thereof.

      ii. Constructed screens may consist of built screens, such as solid walls or fences, topographic screens, such as berms or landforms, vegetative screens consisting entirely of evergreen material, or a combination thereof.

   2. The use of existing vegetation, topography, and natural features to comply with screening requirements is encouraged.

   3. Screening is required to soften the visual impact of buildings, vehicle (car, bus, truck, etc.) parking areas, loading docks, trash disposal areas, exterior storage, and other unsightly areas associated with or generated by a particular development as viewed from public ways, residential zoning districts in Devens and host communities, the Open Space and Recreation Zoning District ("Open Space Zoning District"), and the principal entrance of buildings on abutting lots. The Director shall determine which Improvements shall be screened prior to or during the Pre-Permitting Conference.

   4. Screening may be required along the entire front setback or only a part of it. Screening may also required to extend beyond the minimum setback areas or further into the lot, particularly if the building is located beyond the minimum setback or if the lot configuration is such that the visibility into side or rear setbacks is unimpaired from the public way, residences, the Open Space Zoning District, and principle entrances of buildings on abutting lots.

   5. A minimum of of 50% of built screens such as walls or fences that face the public way, residences, the Open Space Zoning District, and principal entrances on abutting lots shall be softened with plantings.

   6. Vegetative screens shall be visually impermeable year round. Vegetative screens shall be a minimum of two shrubs deep, to a minimum depth of six (6) foot and spaced at such a interval to achieve a visually impermeable screen within three growing seasons (i.e. spacing to be determined by expected rate of growth, not the shrub’s mature size). The minimum height of a screen is three feet upon installation in car parking areas and six feet in other locations, a higher height shall be required if the parking area, loading dock, exterior storage, or other unsightly area is at an elevation lower than the public way, residences, the Open Space Zoning District, and principal entrances of buildings on abutting lots. The height of screens can be the result of combining landforms or natural elevation changes with vegetative material. Screens shall not be located so as to impede vehicular or pedestrian traffic.

   7. Where Improvements requiring screening such as truck parking, loading, service, disposal, or storage areas are adjacent to such Improvements on the abutting lot, the applicant shall provide a screen that is 50% visually permeable, with the understanding that the owner of the abutting parcel is responsible for the other 50% of the screen. The DEC encourages shared responsibilities between abutters for providing and maintaining screening.

   8. Constructed landforms may be used in conjunction with built or vegetative screens. Constructed landforms shall be organic in shape, of differing shapes and sizes if more than one landform is proposed. The side slopes of constructed landforms shall be loamed and planted with vegetation to minimize erosion. Boulders and rocks may be used within landscape treatments, provided at least one-third of the height of the boulder or rock is below ground.

   (h) Landscape Treatment in Parking Areas
   1. Landscape Treatment within parking areas shall provide visual and climatic relief from broad expanses of pavement and shall be designed to channel and define logical areas for pedestrian and vehicular circulation.

   2. The applicant shall provide shade trees around the perimeter of all parking areas at a minimum ratio of one (1) tree per 25 lineal feet of parking lot perimeter. In portions of parking areas where screens are required, the applicant shall provide shade trees along the perimeter at a minimum ratio of one (1) tree per 50 lineal feet of parking lot perimeter in addition to the required screen. Trees shall appear informally arranged, rather than set in straight evenly spaced rows, unless existing trees, or major site elements suggest a formal arrangement. Informally arrange trees may be clustered or grouped, if desired, as long as clusters/groups are not more than 75 feet apart.

   3. Internal parking area plantings are required. Exclusive of perimeter screen planting, internal parking lot landscape areas shall contain one deciduous shade tree for every 20 parking spaces. Trees shall be distributed throughout the parking lot as evenly as possible, although more than one tree may be located on a single island. Trees shall be set back at least five feet minimum from the face of the curb. Tree placement and parking lot lighting shall not conflict. Salt-tolerant shrubs shall be planted along divider islands, preferably native species clustered in groups of five or seven, at a rate of one shrub per each ten feet of divider island length. Interior parking area plantings may be waived in truck parking areas if interior areas are screened from public ways, the principal entrance of any abutting building, the Open Space and Recreation zoning district, or residential zoning district with a year-round visually impervious screen at least six feet tall at installation and perimeter plantings are provided.

   4. Parking area terminal, intermediate, and divider islands shall contain no more than 25% impervious surfaces. The remaining 75% shall be landscaped with grass or other groundcover suitable to the Director. Shrubs planted in islands shall not exceed four feet in height where they might impede vehicular or pedestrian circulation.

   (i) Viewshed Overlay Districts: The Viewshed Overlay District protects scenic vistas from the top of Prospect Hill and the Fruitland Museum. Affected areas in the Devens are shown on Figure H in Appendix B. [974 CMR 3.06(8)]
   1. To the maximum extent feasible, buildings and all topographic alterations in the viewshed shall be located within previously disturbed areas (see 974 CMR 3.06(6) Figure F).

   2. Where buildings encroach on undisturbed wooded areas, the DEC may determine that such encroachment would have a significant adverse effect on the viewshed. To mitigate this adverse effect, the DEC may require that additional trees of at least four inch caliper or clusters of three inch caliper minimum to be planted. The DEC shall determine the spacing, density, size, and location of trees needed to soften the visual impact of the new construction.

   3. If substantial tree canopies do not exist between Prospect Hill and the building, vegetative screen on the side(s) of the building directly facing Prospect Hill may also be required (see 974 CMR 3.06(6) Figure F). This screen shall be located no further away from the building than a distance equal to the building height. Required screens shall extend the full length of the building facing Prospect Hill.
      i.  Landscape Screen on Level Terrain in Viewshed Overlay Districts. If a landscaped screen is required on land at approximately the same elevation as the finished grade of the building, deciduous trees of four-inch minimum caliper and evergreen trees of ten-foot minimum height (with at least one evergreen tree for every three deciduous trees) shall be planted at a density and location specified by the DEC (see 974 CMR 3.06(7) Figure G1).

      ii.   Landscape Screen on Natural or Artificial Berm in Viewshed Overlay Districts. Where a screen is located on land higher than the finished grade of the building, the required deciduous tree caliper can be reduced by ½-inch and evergreen tree height can be reduced by two feet for every three feet of elevation difference compared to the finished grade of the building, to a minimum size of three-inch caliper for deciduous trees and six- foot height for evergreen trees. The number and location of trees planted shall be specified by the DEC.

   4. Buildings within the Viewshed Overlay District shall not have reflective metal flashing, mechanical enclosures, window frames or treatments, doors, roofing material, or building trim and that all metal surfaces shall be finished with a dark, nonreflective finish. Rooftops shall not be illuminated. Signs shall be located below new or existing tree canopies (Article III, Section J of the By-Laws).

   5. Vegetated Rooftops and Vegetated Walls. To the maximum extent feasible buildings within the Viewshed Overlay District that are visible from Prospect Hill at the Sears Estate and/or the Fruitlands Museum and/or residential uses outside of Devens shall have:

      a. vegetated roofs that comply with the DEC’s Vegetative Roof Policy. A vegetated roof is a roof that is covered with vegetation and a growing medium, planted over a waterproofing membrane. It uses a root repellant system, a drainage and filter layer, and a growing medium of at least four inches and plants.

      b. vegetated walls on the sides of the building facing and visible from Prospect Hill at the Sears Estate and/or the Fruitlands Museum and/or residential uses outside Devens. A vegetated wall is a wall, either free-standing or part of a building, that is partially or completely covered with vegetation and, in some cases, soil or an inorganic growing medium. There are two main categories of vegetated walls: vegetated façades and living walls. Vegetated façades are made up of climbing plants either growing directly on a wall or specially designed supporting structures. The plant shoot system grows up the side of the building while being rooted to the ground. In a living wall the modular panels are often made of stainless steel containers, geotextiles, irrigation systems, a growing medium and vegetation.

   6. Landscaping plans for projects located in the Viewshed Overlay District shall show the design and location of vegetated roofs and walls.

   (j) Internal View Corridors (As a Site Design Consideration).

   Within planned developments, such as Innovative Developments (By-Laws Article III, Section F.), campus-like multiple buildings on one or more lots, or urbanized or commercial centers, the internal roadway system shall be landscaped and screened as though the drives are public ways, unless the DEC determines an alternative better suits the development layout and the character of the area. Required screens between adjacent uses within a planned development may be eliminated or reduced if the DEC finds that the screening on the lot effectively blocks views of parking lots, loading areas, refuse collection facilities, and other potentially unattractive areas from adjacent public ways and within the planned development. The applicant shall prepare a landscape treatment plan for the entire planned development area, indicating areas to be screened, materials, locations and types of lighting fixtures, location and plant materials for parking lot buffers, location of signs, and other improvements as determined by the Director.

   (k) Street Trees are shade trees located along a public right-of-way ("street").

   1. Where existing street trees or more than fifty feet apart on average or do not exist along a public right-of-way (“street”), the applicant shall plant street trees. Street trees shall be placed in a linear fashion along the line lot, at a maximum spacing of 50’ on center. Where the character of the site is predominantly wooded or pastoral, the applicant may cluster trees informally along the lot line, with a maximum of 75’ between clusters of three or more trees.

   2. Street trees shall be selected from 3.06(5) List V. The applicant may request the DEC allow other species to be utilized.

   (l) Landscape Treatment of Building Facades visible from Public Ways.
   1. The perimeter of all buildings visible from a public way, the principal entrance of adjacent or abutting buildings or from the Residential or Open Space Zoning Districts shall have continuous landscape treatment in the form of shade trees, ornamental trees, evergreen trees, shrubs, or a combination thereof within 50’ from the face of the building. Landscape treatment shall consist of a minimum of one (1) shade tree per 50 lineal feet of building façade, or three (3) ornamental/evergreen trees per 50 lineal feet of building façade. Trees may be clustered or grouped, if desired. All trees shall be arranged in staggered, triangulated, or informal drifts, unless available space does not permit, or unless existing vegetation is geometrically arranged. Applicant may request a waiver to propose geometrically-based planting arrangements if the proposed building and site plan design strongly merits a more formal arrangement. Foundation planting is not encouraged, but may be allowed at or near primary and secondary building entries (not maintenance, service, or emergency egress entries). Where allowed, the landscaped foundation bed shall be a minimum depth of 20 feet in the Innovation & Technology Business, Innovation & Technology Center, Business/Community Services, Village Growth I & II, and Special Use I & II Zoning Districts, and a minimum of 10 feet depth in all other Districts. The landscaped bed shall consist of shrubs and groundcover to its full horizontal depth, with a minimum of two rows of shrubs.

   2. The Landscape Treatment adjacent to buildings may be reduced or waived by the DEC in cases where it is impractical to provide the specified depth of landscape area due to the size, shape, or other characteristics of the lot; however, in no case shall any parking space or vehicular lane be located closer than 10 feet from the building.

   3. Required landscape beds along building foundations may be substituted with remote (i.e., not abutting the façade) beds of ornamental or evergreen tree plantings.

   (m)   Maintenance.
   1. The owners of any lot shall be responsible for the maintenance of all landscaped open space, natural screens, and constructed screens within the lot. Landscape Treatment shall be maintained in good condition such that planting shall be vigorous and in good health at all times and that the parcel shall present a healthy, neat, and orderly appearance, free from refuse and debris.

   2. The DEC may require a landscape maintenance and water management plan. The maintenance plan shall include but not be limited to the following:

      (a) Integrated Turf Management: mowing schedule, weed control, pest control, soil pH management, fertilizer plan, aeration/dethatching schedule, repair/replacement plan.

      (b) Shrub and Groundcover Management: mulch schedule, weed control, pruning where needed for visibility, preventative pest/disease management, repair/replacement plan.

      (c) Tree Management: mulch schedule, weed control, deadwood removal, pruning schedule, particularly for trees adjacent to walk or roads, fertilizing schedule, preventative pest/disease management, repair/replacement plan.

      (d) Water Systems Management: Water source, system description, spring start-up, fall close-out, system testing schedule, repair/replacement plan. The applicant may install a permanent water supply system consisting of a sprinkler system and/or hose bibs placed at appropriate locations and intervals. Whenever possible, irrigation water shall be derived from sources other than the Devens water system, including “gray water,” re-used water, detained treated stormwater, roof drainage, or water from on-site wells. “Gray water” is water from sinks, showers, dishwashers, and washing machines. On-site cisterns may be installed to store water for irrigation.

      (e) Rodent control: design preventative measures, operational preventative measures, monitoring, schedule, remediative action plan.

      (f) Seasonal Maintenance: Spring clean-up plan, fall clean-up plan, disposal plans for leaves and plant debris, winter plowing plan, winter deicing plan.