Review of Wetland Resource Area Buffer Zone Distances February 2013 Prepared By: Town Of Tewksbury Conservation Commission By-law Subcommittee 1.0 Introduction and Background As part of the Town of Tewksbury’s October 2012 Special Town Meeting warrant, an article had been submitted by residents which would have amended the local wetlands protection bylaw (see Appendix A for article). The primary amendment requested by this article was to change buffer zone distances surrounding wetland resource areas. Following discussions between the Conservation Commission and the article proponents, the article was withdrawn with the understanding that the Conservation Commission would further evaluate the requested amendments. A bylaw subcommittee was formed to perform this evaluation, along with evaluation of other potential bylaw changes/improvements. This report was developed to summarize information collected during the research phase of the buffer zone distance evaluation. The existing wetland bylaw is summarized, along with any available historical background information regarding the basis for the existing buffer zone distances and a master plan evaluation of the bylaw. A summary of various technical research papers is provided, many of which were developed in an attempt to determine appropriate protective buffer zone distances for various land use applications. Review was also performed on distances utilized by Massachusetts municipalities. In most cases, the basis for these distances was unavailable, but they are useful for comparison purposes. Finally, implications of changes to the buffer zone distances are reviewed. 1.1 Buffer Zones - General The need for buffer zones around waterbodies and wetlands is well-documented and will be summarized later in this document. However, the appropriate width of a protective buffer is not clear. Many factors can be used in determining this distance, including: x Wetland function and value; x Intensity of adjacent land use; x Buffer characteristics (e.g., slope and soil type) as it relates to sediment/pollutant removal (both above and below the ground surface) and microclimate protection; and x Wildlife habitat protection and connectivity. Buffer zone management varies by state and municipality. While evaluations of impacts are often performed on a case-by-case basis, due to the amount of effort necessary for determination of an appropriate buffer zone distance, many by-laws and ordinances set minimum buffer widths with various restrictions to make it easier on both developers and reviewers. However, the basis for these set distances is not always based on scientific evidence, but rather “politically” based, where consideration for landowner use, historic decisions, and how neighboring municipalities handle the issue is utilized. In a municipality like Tewksbury, where there are many wetlands/waterbodies and much of the available land is already developed, all of the factors listed above, both scientific and political, must be evaluated to determine the best method for buffer zone management in the municipality. Review of Wetland Resource Area Buffer Zone Distances – February 2013 1 For the purposes of this document, no-disturb zones are those where little to no activity is allowed, maintaining an undisturbed zone, typically right next to the wetland resource area or water body. A no- build zone is typically an additional distance from a no-disturb zone where building of structures is limited so as to protect the no-disturb zone from encroachment. For example, if a no-disturb zone were set at 25 feet from a wetland resource area and there are no limitations to construction beyond this zone, a building could be placed just beyond the 25-foot boundary. This would likely result in future disturbance around the building, at a minimum, for maintenance, thereby encroaching in the no-disturb zone. In this document, distances are defined as being from and parallel to the wetland boundary. 1.2 Commonwealth of Massachusetts Regulations As summarized in Boyd, 2001: “The Massachusetts Wetlands Protection Act (MWPA), (Massachusetts General Laws (M.G.L.) Chapter 131 Section 40) first passed in 1972, is implemented by Chapter 310, Code of Massachusetts Regulations (CMR), Section 10. The purpose of the MWPA is to provide protection to wetland resources with respect to the following eight interests: -Protection of public and private water supply -Protection of ground water supply -Flood control -Storm Damage Prevention -Prevention of Pollution -Protection of Land Containing Shellfish -Protection of Fisheries -Protection of Wildlife Habitat” The Commonwealth of Massachusetts has not defined no-disturb and/or no-build zones. It is left up to local municipalities to enforce how they choose within 100 ft of wetland resource areas (or within 200 ft of rivers/perennial streams). Although this authority is granted to municipalities, decisions are reviewed by the Massachusetts Department of Environmental Protection for consistency and potential mis- interpretation of the MWPA. “The Rivers Protection Act (RPA) was an amendment to the MWPA and is also found in Massachusetts general laws (MGL) Chapter 131 Section 40. It was passed in 1996 and implemented in 1997 by Chapter 310, Code of Massachusetts Regulations, Section 10. The regulation states that riverfront areas protect the same eight interests as the MWPA, and so must be preserved.” Review of Wetland Resource Area Buffer Zone Distances – February 2013 2 1.3 Town of Tewksbury – Wetlands Protection Bylaw [Note that this section summarizes Bylaw information at the time of publication. The Bylaw subcommittee is discussing revisions/clarifications to improve understanding by both residents/developers and Conservation Commissioners.] In the Town of Tewksbury Wetlands Protection Bylaw (August 2012), a 25-foot no-disturb zone and 50- foot no-build zone has been established, with various waivers/activities allowed for each zone. Waivers are often allowed for existing developments/residences in the no-build zone; however, limitation of activities in the no-disturb zone is adhered to in most cases. The bylaw is presented as Appendix B, with the distances defined in Section 18.04.30 and exceptions/variances defined in Section 18.04.40 and performance standards listed in Section 18.04.45. General allowances/prohibitions are presented below (both summarized and via specific excerpts). Following the discussion of the existing bylaw, example scenarios for residents are presented to potentially provide a better understanding of some of the typical scenarios reviewed by the Commission. In addition, the history of the existing bylaw buffer zone distances is summarized for improved understanding. Note that maintaining, repairing or replacing, but not substantially changing or enlarging, an existing and lawfully located building (residential/commercial) does not require an application to the Commission. Additional exemptions are allowed for facilities used in the service of the public (i.e., utilities), agricultural use, and mosquito control. Maintenance of existing landscaping, including lawn mowing and pruning, is exempt from Commission review regardless of location in the buffer zone or any wetland resource area. 25-foot No-Disturb Zone – Undisturbed, natural vegetation. Except for certain cases, no activity is permitted within this zone, including, but not limited to, grading, landscaping, vegetation clearing, cutting, filling, excavating, road construction, and driveway construction. “This standard has been adopted because the alteration of land immediately adjacent to a wetland is likely to result in the alteration of the wetland itself. Alterations typically result from extension of lawns, depositing/ dumping of yard waste, over grading, siltation, deposition of construction debris, unregulated filling, and clearing of vegetation, all of which is prohibited.” Note that historic alteration of this zone (e.g., lawn encroachment) does not reduce this distance as being enforceable under the existing bylaw. However, a presumption of significance (of any part of the buffer zone) may be overcome upon a showing of clear and convincing evidence demonstrating that the buffer zone does not play a role in the protection of the wetland/water body. Discussion of variables contributing to buffer zone protectiveness is presented later in this report. Review of Wetland Resource Area Buffer Zone Distances – February 2013 3 50-foot No-Build Zone – x Proposed (new) buildings or structures must stay outside of this zone; x Mitigation options are provided for unavoidable partial encroachment into this zone. x Stormwater management structures/components are allowed in this zone; x These tasks do not need review by the Commission: o Unpaved pedestrian walkways for private use; o Fencing that does not create a barrier to wildlife movement; o Stone walls without mortared foundations; o Stacks of cordwood; o Vista pruning (see bylaw text for restrictions); o Planting of native trees, shrubs, or groundcover, but not turf lawns [turf lawn installation in this zone requires review by the Commission]; o Conversion of lawns to decks, sheds, patios, and pools that accessory to single family homes which existed prior to May 1, 2002 (runoff controls must be used during construction); o Conversion of patios, pools, sheds, or other impervious surfaces to lawn or natural vegetation; and o Activities, such as monitoring wells, exploratory borings, soil sampling, and surveying, that are temporary, have negligible