A. 
Definition, critical characteristics, boundary, presumption of existence.
(1) 
Definition, critical characteristics. A vernal pool is defined in the Bylaw at § 227-9 as any confined basin or depression not occurring in existing lawns, gardens, landscaped areas or driveways that holds water, at least in most years, for a minimum of two continuous months during the spring and/or summer; contains at least 200 cubic feet of water; is free of adult predatory fish populations; and provides essential breeding and rearing habitat functions for amphibians, reptiles, or other vernal pool community species, regardless of whether the site has been certified by the Massachusetts Division of Fisheries and Wildlife.
(2) 
Boundary. The boundary of the resource area for a vernal pool shall be 100 feet outward from the mean annual high-water line defining the depression, but shall not include a lawn, garden, landscaped area or developed area in existence and maintained since at the time of the effective date of this provision in this chapter.
B. 
Presumptions, findings.
(1) 
Presumption that confined basin and adjacent land is a vernal pool. The Bylaw presumes that all areas meeting the definition of "vernal pool" perform essential wildlife habitat. These areas are essential breeding habitat, and provide other important wildlife habitat functions, during non-breeding season, for a variety of amphibian species including, but not limited to, the wood frog (Rana sylvatica), as well as the blue-spotted salamander (Ambystoma laterale) and marbled salamander (Ambystoma opacum). A vernal pool is highly likely to be significant to wildlife habitat, rare species habitat, groundwater supply, and flood control. This presumption may be overcome only by the presentation of credible evidence which, in the judgment of the Commission, demonstrates that the basin or depression, or the adjacent land, does not meet the physical criteria of the definition, or, if it meets such criteria, does not provide essential habitat and wetland functions. Any formal evaluation should be performed by an individual meeting the qualifications under the wildlife habitat section of the Wetlands Protection Act Regulations.
C. 
Performance standards.
(1) 
Activity or work that will result in altering the vernal pool or land within the buffer zone of any vernal pool, shall be considered to be adverse to the interests protected by the Bylaw and these regulations and generally shall be prohibited by the Conservation Commission. The Commission may grant a waiver of this performance standard only as provided in § 503-22 of the Easton Town Code. Activities or Work contemplated hereunder shall include, but not be limited to, point-source stormwater discharges to Vernal Pools and their buffer zones.
(2) 
Buffer zone. Land within 100 feet of a vernal pool boundary is likely to be significant to the protection and maintenance of the vernal pool and, therefore, to the protection of the Bylaw wetland values. The Commission shall not allow alteration in the entire buffer zone of a vernal pool unless the Commission grants a waiver to this performance standard of no alteration as further provided in § 503-21 of the Easton Town Code.
(3) 
Where the Bylaw resource area of vernal pool is within an area of critical environmental concern, an additional 100 feet of jurisdictional area is added to the outer boundary of the buffer zone. The Commission generally shall not allow the application of new pavement or other impervious materials within the vernal pool or the buffer zone to the vernal pool as provided in § 503-22 of the Easton Town Code. The Commission may grant a waiver of this performance standard as provided in § 503-22 of the Easton Town Code.
A. 
Definition, critical characteristics, boundary.
(1) 
Reservoir: a naturally occurring lake or pond or other basin where water is collected and stored for future use.
(2) 
Lake: A Lake means any open body of freshwater with a surface area of 10 acres or more. Any pond over 10 acres is usually called a "lake," but the term is synonymous with a pond.
(3) 
Pond: A pond is any open body of fresh water, either naturally occurring or manmade by impoundment, excavation, or otherwise, which is never without standing water due to natural causes, except in periods of extended drought. Notwithstanding the above, the following man- made bodies of open water shall not be considered ponds:
(a) 
basins or lagoons that are part of wastewater treatment plants,
(b) 
swimming pools or other impervious man-made retention basins;
(c) 
man-made fish ponds; and
(d) 
individual gravel pits or quarries excavated from upland areas unless inactive for five or more consecutive years.
B. 
Presumption of significance, findings. The Conservation Commission shall presume that protection of the resource areas protected under the Bylaw, a reservoir, lake, and pond, are significant to the Bylaw wetland values, specified in § 503-1B of the Easton Town Code.
C. 
Performance standards.
(1) 
The Commission shall apply the performance standards of bank and land under water bodies and waterways in assessing a proposed project that would alter either a perennial or intermittent stream.
(2) 
A reservoir, lake, and pond each have a 100-foot buffer zone and may have a 200-foot riverfront area under the Bylaw and these areas are classified as resource areas subject to protection under the Bylaw. Consequently, the Conservation Commission shall apply the performance standards of the riverfront area in assessing a proposed project that would alter a reservoir, lake, or pond.
A. 
Definition, critical characteristics, boundary.
(1) 
River (perennial stream).
(a) 
A river (perennial stream) is any natural or man-made flowing body of water that empties to any ocean, lake, pond, wetland, or other perennial stream and which flows throughout the year. A river is a perennial stream. A river or perennial stream is characterized by horizontal zonation, as opposed to the vertical stratification typically associated with lakes, ponds, and embayments.
[1] 
A river or stream shown as perennial on the current United States Geological Survey (USGS) is perennial.
[2] 
A river or stream shown as intermittent or not shown on the current USGS map that has a watershed size greater than or equal to one square mile is perennial.
[3] 
A stream shown as intermittent or not shown on the current USGS map or more recent map provided by the Department that has a watershed size less than one square mile is perennial if the stream has a watershed size of at least 0.50 square mile and has a predicted flow rate greater than or equal to 0.01 cubic feet per second at the 99% flow duration using the USGS Stream Stats method.
[4] 
When the USGS StreamStats method cannot be used because the stream does not have a mapped and digitized centerline and the stream has a watershed size of at least 0.50 square mile, and the surficial geology of the contributing drainage area to the stream at the project site contains 75% or more stratified drift, the issuing authority shall find such streams to be perennial. Stratified drift shall mean sand and gravel deposits that have been layered and sorted by glacial meltwater streams. Areal percentages of stratified drift may be determined using USGS surficial geologic maps, USGS Hydrological Atlases, Massachusetts Geographical Information System (MassGIS) surficial geology data layer, or other published or electronic surficial geological information from a credible source.
[5] 
Rivers include perennial streams that cease to flow during periods of extended drought. Rivers and streams that are perennial under natural conditions but are significantly affected by drawdown from withdrawals of water supply wells, direct withdrawals, impoundments, or other manmade flow reductions or diversions shall be considered perennial.
(b) 
Where a river (perennial stream) flows through a culvert of any length it does not lose its classification as a river.
(2) 
Stream (creek, intermittent stream).
(a) 
An intermittent stream is that segment of a flowing watercourse, natural or manmade, that regularly experiences naturally occurring sporadic flow interruptions such that it does not have a continuous sheet of surface water for five consecutive days or more annually. Intermittent streams exhibit a longitudinal gradient of hydrology, from:
[1] 
ephemeral channels that flow only in response to storms;
[2] 
intermittent sections that flow seasonally until the groundwater table falls below the channel and are dry the rest of the year; and
[3] 
interstitial reaches that flow seasonally and retain pools connected by subsurface flow during the summer.
(b) 
Where there is a question as to whether a stream is intermittent or perennial, the Commission shall find any stream is intermittent based upon a documented field observation that the stream is not flowing. A documented field observation shall be made by a competent source and shall be based upon an observation made at least once per day, over four days in any consecutive twelve-month period, during a non-drought period on a stream not significantly affected by drawdown from withdrawals of water supply wells, direct withdrawals, impoundments, or other man-made flow reductions or diversions. Field observations shall be documented by field notes and by dated photographs or video. All field observations shall be submitted to the Conservation Commission with a statement signed under the penalties of perjury attesting to the authenticity and veracity of the field notes, photographs or video and other credible evidence. Department staff, conservation commissioners, and conservation commission staff are competent sources; issuing authorities may consider evidence from other sources that are determined to be competent.
(c) 
The Conservation Commission recognizes four types of intermittent streams:
[1] 
Type I: a stream segment that originates at the headstream and is sometimes associated with forested seeps and small wetlands and include headwater (first- through third-order) streams, which are important both for aquatic biodiversity and for ecological function of lower stream reaches.
[2] 
Type II: a stream segment that does not originate at the headstream in which continuous standing water disappears for at least five but not more than 30 consecutive days annually.
[3] 
Type III: a stream segment that does not originate at the headstream in which continuous standing water disappears for more than 30 consecutive days annually.
[4] 
Type IV: a stream segment, without regard to duration of continuous standing water, that connects two culvert pipes or otherwise functions as a man-made drainage channel within an already developed area.
B. 
Presumption of significance, findings. The Conservation Commission shall presume that protection of a river and a stream is significant to the Bylaw wetland values, specified in § 503-1B of the Easton Town Code.
(1) 
River (perennial stream).
(a) 
A river (perennial stream) serves as public and private water supplies. In addition, a river is important for storm damage prevention, flood control, groundwater protection, wildlife habitat, and recreation values.
(b) 
The surface water interaction with groundwater significantly influences the ecosystem of a river. The dynamic relationship between surface and groundwater within the "hyporheic zone" sustains communities of aquatic organisms which regulate the flux of nutrients, biomass and the productivity of organisms including fish within the stream itself. The hyporheic zone extends to greater distances horizontally from the channel in large, higher-order streams with alluvial floodplains, but the interaction within this zone is important in smaller streams as well.
(2) 
Intermittent stream (creek).
(a) 
Intermittent streams are important for storm damage prevention, flood control, groundwater protection, wildlife habitat, and recreation values. During spring, summer, and fall these streams disperse snow melt and storm runoff across the landscape thereby preventing dangerous volumes and flows from spilling over roadways and property. This board dispersal also allows for larger volumes of water to infiltrate into the ground, recharging groundwater supplies.
(b) 
Intermittent streams are an essential source of food and water for wildlife, and are often the only source of water in higher elevation areas of Town. The moist soils that border intermittent streams are significantly richer in herbs and flowering/fruiting plants, the base tropic level of food, than surrounding upland areas.
(c) 
During all seasons, but especially in winter and spring, intermittent streams act as essential corridors for animal movement when food is scarce. Some animals, such as pickerel frogs and eastern spotted newts, rely heavily on intermittent streams for movement.
(d) 
For the above reasons the upland areas surrounding intermittent streams are heavily utilized by wildlife for living space, breeding, feeding, migrating, dispersal, and security. Accordingly, the Bylaw protects intermittent streams of all forms and the adjacent upland resource within 200 feet of those streams (the riverfront area).
C. 
Performance standards.
(1) 
The Commission shall apply the performance standards of bank and land under water bodies and waterways in assessing a proposed project that would alter either a perennial or intermittent stream.
(2) 
A river and a stream each have a 200-foot riverfront area under the Bylaw and these areas are classified as resource areas subject to protection under the Bylaw. Consequently, the Conservation Commission shall apply the performance standards of the riverfront area in assessing a proposed project that would alter either a river or stream.
A. 
Preamble, definition, presumptions, and performance standards are consistent with Wetland Protection Act Regulations 310 CMR 10.54, except:
(1) 
The upper boundary of a bank is the first observable break in the slope of the mean annual flood level or the mean annual flood level, whichever is higher. The lower boundary of a bank is the mean annual low flow level.
(2) 
The Conservation Commission shall presume that protection of a bank is significant to the Bylaw wetland values specified in § 503-1B of the Easton Town Code.
(3) 
Additional Standards for ACEC. Where the Bylaw resource area of bank is within an area of critical environmental concern, the Commission shall not allow the application of new pavement or other impervious materials within the bank or the additional 100-foot buffer zone to the bank and shall regulate the application of impervious materials in the restricted area beyond the 100-foot buffer zone in accordance with § 503-23B(2) of the Easton Town Code. The Commission may grant a waiver of this performance standard as provided in § 503-22 of the Easton Town Code.
A. 
Preamble, definition, and presumptions are consistent with Wetland Protection Act Regulations 310 CMR 10.55, except:
(1) 
Vegetated wetlands ("freshwater wetlands" as provided in the Bylaw at § 227-2 of the Easton Town Code) are areas where the topography is low and where the soils are annually saturated. Vegetated wetlands may be bordering on surface water bodies or other Bylaw resource areas, or they may be isolated. Vegetated wetlands may be of any size.
(2) 
Vegetated wetlands also include areas where groundwater, flowing or standing surface water, or ice provides a significant part of the supporting substrate for a plant community for at least five months of the year, such as a seep, and areas of emergent and submerged plant communities in inland waters.
(3) 
The boundaries of a vegetated wetland are the line within which 50% or more of the vegetative community consists of wetland species identified in the Wetlands Protection. Act. Alternatively, if the vegetative community has been disturbed, then the boundaries may be determined in accordance with the standards of Subsection A(4) below.
(4) 
The boundary of a vegetated wetland that has been disturbed (e.g., by cutting, filling, or cultivation), the boundary is the line within which there are indicators of saturated or inundated conditions sufficient to support a predominance of wetland indicator plants, a predominance of wetland indicator plants, or credible evidence from a competent source that the area supported or would support under undisturbed conditions a predominance of wetland indicator plants before the disturbance.
B. 
Presumption of significance; findings.
(1) 
The physical characteristics of vegetated wetlands, are critical to the protection of the Bylaw wetland values. The Conservation Commission shall presume that protection of a vegetated wetland, whether bordering or isolated, is significant to the Bylaw wetland values § 503-1B of the Easton Town Code. This presumption of significance may be rebutted upon a showing by clear and convincing evidence that the vegetated wetland does not play a role in the protection of the Bylaw wetland values.
(a) 
Where the Conservation Commission determines that the presumption of significance of the vegetated wetland to one or more, but not all, Bylaw wetland values has been overcome, the Commission shall make a written determination to this effect, setting forth its grounds as part of its findings in the permit for work or denial of the permit for work.
(b) 
Where the Conservation Commission determines that the presumption of significance of the vegetated wetland to all Bylaw wetland values has been overcome, the Commission shall make a written determination to this effect, setting forth its grounds in a determination of nonsignificance.
(2) 
Vegetated wetlands are likely to be significant to wildlife, and to the protection of shellfish.
(3) 
Vegetated wetlands are also important to the protection of rare and endangered wildlife species.
(4) 
Vegetated wetlands, together with land within 100 feet of a vegetated wetland (the buffer zone) serve to moderate and alleviate thermal shock and pollution resulting from runoff from impervious surfaces, which may be detrimental to wildlife, fisheries, and shellfish downstream of the vegetated wetland.
C. 
Performance standards.
(1) 
No activity or work, other than the maintenance of an already existing structure, which will result in the building within or upon, removing, filling, or altering of a vegetated wetland, or land within 50 feet of any vegetated wetland (the fifty-foot inner buffer zone), shall be permitted by the Conservation Commission. The Commission may grant a waiver of this performance standard as provided in § 503-22 of the Easton Town Code.
(2) 
Any activity that the Conservation Commission allows pursuant to the criteria upon or within 50 feet of a vegetated wetland shall not impair in any way the ability of the Vegetated Wetland to perform any of the functions.
(3) 
Additional standards for ACEC. Where the Bylaw resource area of vegetated wetlands is within an area of critical environmental concern, an additional 100 feet of jurisdictional area past the outer buffer zone boundary is regulated. The Commission shall not allow the application of new pavement or other impervious materials within the vegetated wetlands or the 100-foot buffer zone to the vegetated wetlands and shall regulate the application of impervious materials in the restricted area beyond the 100-foot buffer zone in accordance with § 503-23B(2) of the Easton Town Code. The Commission may grant a waiver of this performance standard as provided in § 503-22 of the Easton Town Code.
A. 
Preamble, definition, and presumptions are consistent with Wetland Protection Act Regulations 310 CMR 10.56, except:
(1) 
Land under water bodies and waterways is the land beneath any reservoir.
(2) 
The boundary of land under water bodies and waterways is the mean low water level.
(3) 
The Conservation Commission shall presume that protection of land under water bodies and waterways is significant to the Bylaw wetland values specified in § 503-1B of the Easton Town Code.
(4) 
Land under water bodies and waterways is likely to be significant to wildlife. Land within 100 feet of land under water bodies and waterways is likely to be significant to the protection and maintenance of the land under water bodies and waterways and, therefore, to the protection of the Bylaw wetland values that this Bylaw resource area serves to protect. Said hundred-foot buffer zone is regulated under § 503-20 of the Easton Town Code.
B. 
Performance standards.
(1) 
No activity or work, other than the maintenance of an already existing structure, which will result in the building within or upon, removing, filling, or altering of land under water bodies and waterways, or land within 50 feet of any land under water bodies and waterways (the fifty-foot inner buffer zone), shall be permitted by the Conservation Commission. The Commission may grant a waiver of this performance standard as provided in § 503-22 of the Easton Town Code.
(2) 
Any activity that the Conservation Commission allows pursuant to the criteria upon or within 50 feet of land under water bodies and waterways shall not impair in any way the ability of the land under water bodies and waterways to perform any of the functions.
(3) 
Additional standards for ACEC. Where the Bylaw resource area of land under water bodies is within an area of critical environmental concern, an additional 100 feet of jurisdictional area is added to the outer buffer zone boundary. The Commission shall not allow the application of new pavement or other impervious materials within the land under water bodies or the 100-foot buffer zone to the land under water bodies and shall regulate the application of impervious materials in the restricted area beyond the 100-foot buffer zone. The Commission may grant a waiver of this performance standard as provided in § 503-22 of the Easton Town Code.
A. 
Preamble, definition, and presumptions are consistent with Wetland Protection Act Regulations 310 CMR 10.57, except:
(1) 
Bordering land subject to flooding.
(a) 
Bordering land subject to flooding is an area with low, flat topography adjacent to and inundated by flood waters rising from reservoirs.
(2) 
Isolated land subject to flooding.
(a) 
Isolated land subject to flooding is an isolated depression or closed basin without an inlet or an outlet. It is an area that at least once a year confines standing water of any volume.
B. 
Presumption of significance; findings. The Conservation Commission shall presume that protection of land subject to flooding, both bordering and isolated, is significant to the Bylaw wetland values specified in § 503-1B of the Easton Town Code.
(1) 
Bordering land subject to flooding.
(a) 
The topography and location of bordering land subject to flooding are critical to the protection of the Bylaw wetland values of flood control and storm damage prevention.
(2) 
Isolated land subject to flooding.
(a) 
Isolated land subject to flooding provides important breeding habitat for amphibians and some rare plants.
C. 
Performance standards for bordering and isolated land subject to flooding.
(1) 
No activity or work, other than the maintenance of an already existing structure, which will result in the building within or upon, removing, filling, or altering of land subject to flooding, or land within 50 feet of any land subject to flooding (the fifty-foot inner buffer zone), shall be permitted by the Conservation Commission. The Commission may grant a waiver of this performance standard as provided in § 503-22 of the Easton Town Code.
(2) 
Any activity that the Conservation Commission allows pursuant to the criteria in the aforesaid Subsection C(1) upon or within 50 feet of a land subject to flooding shall not impair in any way the ability of the land subject to flooding to perform any of the functions in protecting Bylaw wetland values.
A. 
Definition, critical characteristics, boundary.
(1) 
A buffer zone is a resource area subject to protection under the Bylaw that is land extending 100 feet horizontally outward from the boundary of the following Bylaw resource areas: vernal pools; reservoirs, lakes, and ponds; banks; vegetated wetlands, whether bordering or isolated; lands under water bodies; and lands subject to flooding, both bordering and isolated.
B. 
Presumption of significance; findings.
(1) 
The Conservation Commission shall presume that protection of the Buffer Zone is significant to the Bylaw wetland values specified in § 503-1B of the Easton Town Code.
(2) 
A buffer zone is highly likely to be significant to the Bylaw wetland values listed in § 503-1B of the Easton Town Code, and in protecting these Bylaw wetland values in many ways, including but not limited to:
(a) 
Moderating water temperature by providing shade and cover through the riparian vegetation growing within the buffer zone.
(b) 
Filtering sediments, pollutants, and other contaminants (e.g., pesticides and heavy metals) from surface flow.
(c) 
Preventing erosion in riparian areas and precluding development that could lead to increased contaminant loading.
(d) 
Reducing nutrient inputs into streams by i) filtering from surface flow the nutrient bound to sediments; ii) removing nutrients from groundwater through uptake in vegetation and by denitrification, and iii) precluding development that could increase nutrient loading, for example, septic systems, fertilized lawns, and landscaping.
(e) 
Maintaining stream flow by storing water, thus helping maintain the base flow and water quality during low-flow periods.
(f) 
Providing one of the richest habitat zones for aquatic organisms, mammals, birds, and amphibians in the vegetated uplands adjacent to vegetated wetlands.
(g) 
Providing corridors critical for wildlife movement.
C. 
Performance standards.
(1) 
Inner fifty-foot no-disturbance zone for undisturbed lands.
(a) 
Undisturbed land is land determined by the Conservation Commission to be of a predominantly natural character or.
[1] 
Lands that have been altered without a permit for work from the Commission or an order of conditions under the Wetlands Protection Act after December 8, 1986 is also considered undisturbed.
(b) 
No alterations are permitted within the inner 50 feet of the buffer zone.
(c) 
Prohibited alterations include, but are not limited to, grading, landscaping, clearing or cutting of vegetation, filling, excavating, and construction of roads or structures.
[1] 
Structures include, but are not limited to, single-family houses, multifamily dwellings, commercial or industrial buildings, porches, decks, house additions, pools, septic systems and any of its components, and sheds.
[2] 
Driveways, roadways, fences, walls, septic system repairs, and facilities for stormwater management may be allowed in the fifty-foot no-disturbance zone, when no other feasible alternatives exist; provided, however, that no new septic system connecting pipes (as well as the prohibited tank and sub-surface soil absorption system) shall be allowed in the inner fifty-foot buffer zone to a BVW or bank.
(2) 
Inner fifty-foot no-disturbance zone for disturbed lands.
(a) 
Disturbed land is land determined by the Conservation Commission to be of a legally modified nature that was altered before December 8, 1986, or after that date with a permit for work from the Commission or an order of conditions under the Wetlands Protection Act.
(b) 
The Conservation Commission shall not permit any alteration resulting in a net increase in impervious surface area, a net increase in non-native or invasive species, a net increase in stormwater runoff, a net increase in lawn area, or net decrease in vegetative cover within the inner 50 feet of the buffer zone.
(c) 
No structures shall be constructed or placed on pervious surfaces and no driveways, roadways, fences, walls, and facilities for stormwater management may be allowed within the inner 50 feet of the buffer zone without compensatory restoration and mitigation.
(d) 
No components of a new septic system shall be constructed within the previously disturbed inner fifty-foot buffer zone to a BVW or a bank. Components shall include, but not limited to, connecting pipes, holding tanks, distribution boxes, and subsurface soil absorption systems.
(3) 
Outer fifty-foot buffer zone. Activities within the outer 50 feet of a buffer zone shall not adversely affect the form or function of the adjacent Bylaw resource area or the inner fifty-foot no-disturbance zone of the buffer zone.
(4) 
Vernal pool buffer zone. The Conservation Commission shall not permit any alteration within the entire 100-foot buffer zone of a vernal pool, unless the Commission grants a waiver under the provisions of § 503-22 of the Easton Town Code and the Commission is not otherwise prohibited from granting such waiver by the provisions of Chapter 503 of the Easton Town Code, and, if granted, such waiver shall have same conditions and performance standards, the inner fifty-foot no-disturbance zone for undisturbed lands.
A. 
Preamble, definition, and presumptions are consistent with Wetland Protection Act Regulations 310 CMR 10.57, except:
(1) 
Riverfront areas apply to intermittent streams as defined in the Bylaw regulations (§ 503-14).
(2) 
Where a river (perennial stream) or stream (intermittent stream) flows through a lake or pond, the riverfront area continues and the inner boundary of the riverfront area is measured from the bank of the reservoir, lake, or pond.
Presumption of significance; findings.
(3) 
The Conservation Commission shall presume that protection of the riverfront area is significant to the Bylaw wetland values specified in § 503-1B of the Easton Town Code.
B. 
Performance standards.
(1) 
Performance standards for riverfront area of a river or stream. No activity or work, other than the maintenance of an already existing structure, which will result in the building within or upon, removing, filling, or altering of the 200-foot riverfront area shall be permitted by the Conservation Commission. The Commission may grant a waiver of this performance standard as provided in § 503-22 of the Easton Town Code.
(a) 
Single-family house discretionary exception. The Conservation Commission may allow the construction of a single-family house, a septic system if no sewer is available, and a driveway, on a lot recorded before April 8, 2002, where the size or shape of the lot within the riverfront area prevents the construction from meeting the requirements, provided that: a) the lot can be developed for such purposes under the applicable provisions of other municipal and state law; b) the performance standards are met to the maximum extent feasible; and c) the Commission is not otherwise prohibited from allowing such under another provision of Chapter 503 of the Easton Town Code. In difficult situations, the maximum extent of yard around houses should be limited to the area necessary for construction. Except where the lot contains vernal pool habitat or specified habitat sites of rare species, a wildlife habitat evaluation study shall not be required.
(b) 
Additional Standards for ACEC. Where the Riverfront Area is within an area of critical environmental concern. The Commission shall not allow the application of new pavement or other impervious materials within the Riverfront Area and shall regulate the application of impervious materials in the restricted area beyond the 100-foot buffer zone. The Commission may grant a waiver of this performance standard as provided in § 503-22 of the Easton Town Code.
(c) 
Performance standards for redevelopment. Where the proposed project is a redevelopment of a previously altered riverfront area to either a perennial or an intermittent stream, then the criteria found in Mass. Regs. Code tit. 310, § 10.58(5), apply in lieu of the alternatives analysis performance standard stated in the aforesaid with the exception that no new structure may be placed on a pervious surface within the first 50 feet of the Riverfront Area.
(2) 
For proposed activity and work within the riverfront area of a river (perennial stream), the activity or work shall comply with Wetlands Protection Act 310 CMR 10.58.
(3) 
For proposed activity or work within the riverfront area of intermittent streams should apply with the following performance standards:
(a) 
Ten percent for protected lot. The Commission may, in unusual circumstances, allow, as a consideration and not as a right, the alteration of up to 10% of the riverfront area within the lot, on a lot recorded on or before April 8, 2002, or up to 10% of the riverfront area within a lot recorded after April 8, 2002, provided that:
[1] 
At a minimum, a 150-foot-wide area of undisturbed vegetation is provided. This area shall extend from mean annual high water along the river unless another location would better protect the values identified in the Bylaw and regulations.
[a] 
If there is not a 150-foot-wide area of undisturbed vegetation within the riverfront area, existing vegetative cover shall be preserved or extended to the maximum extent feasible to approximate a 150-foot-wide corridor of natural vegetation.
[b] 
Replication and compensatory storage required to meet other resource area performance standards are not allowed within this area; structural stormwater management measures may be allowed only when there is no practicable alternative.
[c] 
Temporary impacts where necessary for installation of linear site related utilities are allowed, provided the area is restored to its natural conditions.
[2] 
Stormwater is managed according to standards established by the Department of Environmental Protection.
[3] 
The proposed work does not impair the capacity of the riverfront area to provide important wildlife habitat functions.
[4] 
The proposed work shall not impair groundwater or surface water quality by incorporating erosion and sedimentation controls and other measures to attenuate nonpoint source pollution. The calculation of square footage of alteration shall exclude areas of replication or compensatory flood storage required to meet performance standards for other resource areas, or any area of restoration within the riverfront area. The calculation also shall exclude areas used for structural stormwater management measures, provided there is no practicable alternative to locating these structures within the riverfront area and provided a wildlife corridor is maintained (e.g., detention basins shall not be fenced).
[5] 
Other Bylaw resource areas. The work must meet the performance standards for all other resource areas subject to protection under the Bylaw that are located within the riverfront area, including the 100-foot buffer zone.