Key regulations from the Conservation Commission regarding the installation and maintenance of fencing projects. From the regulations promulgated July 1, 2019.
DEFINITIONS
Coastal engineering structure (CES): includes and not limited to any breakwater, bulkhead, groin, jetty, revetment, seawall, weir, riprap, gabions, marine mattress, sandbags, or other structure that is designed to alter wave, tidal or sediment transport processes in order to protect inland or upland structures from the effects of such processes. Planting of vegetation and placement of biodegradable netting or fabric shall not be considered a CES.
Serpentine fencing (also called "Drift" Fencing): Timber posts shall be dug five (5) to six (6) feet into the beach, connected by 6-10-foot spans of fencing comprised of 2”x4” frames and 2”x3” slats. Space between slats is a minimum of 3". Fence posts are usually piles and are installed alternating 2' on either side of a center line so that a "zig zag" or "serpentine" structure results.
7.05 Biomimicry, Serpentine fence, nourishment and planting of beach grass
No fencing shall be erected or maintained, nor shall any vegetation be planted in a coastal resource area within the Town of Truro without the prior approval of the Truro Conservation Commission. Planting of native vegetation, installation of Sand (rolls of lightweight fencing) and Drift (Serpentine) fencing may be permitted as set forth below. Layered sand fencing may be permitted on both ocean and bay sides of Truro. Drift (serpentine) fencing may only be erected on the bay side. Layered (two rows) Drift fencing shall only be permitted under special circumstances and in limited areas and shall be sought by application for a waiver. Hardened fencing, seawalls, revetments or bulkheads shall not be allowed, except as specifically provided in 310C.M.R. 10.30 (3), which states that coastal engineering structures cannot be permitted when a coastal bank “is significant to storm damage prevention or flood control because it supplies sediment to coastal beaches, coastal dunes and barrier beaches”.
1. Maintenance or repair of existing bulkheads and revetments shall only be by prior approval of the Truro Conservation Commission. Engineering structures shall not be permitted as defined in 310 C.M.R 10.23:
2. A fencing solution may not be appropriate for every property. Initially, the applicant should determine the appropriate type and extent of installation for their situation. Factors to consider may include the amount of vegetation, existence of a dune currently, angle of repose, recent cutting or evidence of past bank erosion. The Conservation Commission may request an outside consultant to review this assessment at the applicant’s expense according to the Wetlands Regulations.
3. Local, state and federal regulatory agencies strongly encourage the use of non-structural measures to reduce the impacts of storm damage and flooding. Structural measures often create adverse effects on subject property as well as adjacent and nearby beaches by increasing erosion through wave reflection and by eliminating important sediment sources. The optimum landward dune location is often above the seasonal average storm tide elevation. Over time this elevation changes and naturally settles in a more landward position.
When storm activity erodes coastal dunes, the material eroded remains part of the overall coastal system and provides nourishment for downdrift beaches and nearshore sand bars. Once fair-weather beach processes resume following a storm, the sand from sand bars migrates seasonally back to the beach, and then wind-blown sand from the beach naturally rebuilds the dunes. The dune rebuilding process can take several years, and in certain cases it may be desirable to rebuild a storm-eroded dune more quickly.
4. Any fencing activity should be viewed as a temporary measure to initially trap higher volumes of sand than American beach grass could alone. Once the beach grass is established, it has been proven to trap sand at a rate comparable to multiple sand fences. Holding a dune unnaturally seaward of the storm tide elevation at any given time creates problems for abutting properties and ultimately can negatively affect the distribution of sediment along an entire coastline alongshore, as well as on and off shore where bars provide important storm protection.
5. Definitions:
a) Sand fencing. Also sold as “snow fencing” in 50-foot-long rolls, 4 feet high. The rolls can be chain sawed in half to produce 100 feet of 2-foot-high fencing. Constructed of lightweight wooden slats, factory wired together with spaces between the slats approximately equal to slat width (approx. 1.5 inches). Fencing may be installed in three 10’ wide rows parallel to the shoreline, or in zig-zag pattern. Two-foot-high fencing may be installed by driving the individual slats into the sand with a rubber mallet. Four-foot-high fences may be supported by wooden posts, attached with screws or plastic ties.
b) Drift Fencing: (also called “Serpentine” Fencing): Ten-foot timber posts dug at six feet into the sand at grade at the time of installation, connected by 6 to 10-foot spans of fencing comprised of 2x4 spans and 2x3 slats. Space between slats is a minimum of 3”. Fence posts are installed alternating 2’ on either side of a center line so that a “zig-zag” or serpentine structure results.
c) Hardened fencing: Any Sand or Drift fencing backed by landscape fabric, bracing spans of wood, or packed with beach debris, straw, or any other material intended to or actually providing greater blockage of sand and water than would be caused by the fencing alone.
d) Biomimicry Sand Collection System*: Refers to random patterns of thin cedar shims inserted into several inches of sand that mimic native beach vegetation by collecting and stabilizing windblown sand. The shims are inserted several inches into the sand, spaced 10-14 inches apart, in a random matrix from 4-6 feet wide, along the upper beach. During wind events, the matrix performs by collecting sand. When sand levels rise, the slats are pulled up higher, to continue performing. In this manner, additional shims can also be used to widen the desired sand collection profile. Biomimicry* creates dunes by minimally interacting with available energy in the coastal resource system.
6. Options for Property Owners:
a) No Installation: A property owner may choose to not install any fencing. Some properties along the bay side do not have fencing and have grown dunes back following erosion events. Gently sloping, wider seaward-facing dunes are less prone than steep slopes to storm wave loss of sand. Through experimentation it was shown that planted dunes on Cape Cod create lower and wider dunes than fence-built dunes. The lower, wider dunes that form without fencing result in less sediment loss during typical storm events.
b) Sand fencing: Sand fencing is commonly used along the Eastern United States to encourage deposition of wind-blown sand to help re-build a dune. The effectiveness of this method in any given area depends upon availability of adequate amounts of wind-blown sand. The degree of success a fencing system will have in any given location varies along the coast line, therefore each site should be examined individually, and in conjunction with neighboring properties. The rolled sand fencing interferes less with natural processes.
c) Drift fencing: The fencing approach is intended to encourage deposition, and thereby slow erosion, it is not intended to hold a dune in place. Installation of a fence of this nature must not be confused with an engineering structure as defined in the wetland protection regulations 310CMR 10.00.
d) Biomimicry sand collection system: This sand collection system performs by collecting sand during wind events, typically during the winter storm season. Collected sand is completely compatible for dune restoration projects, such as restoring the toe of a coastal bank or eroded toe of a dune.
7. Procedure:
a) Notice of Intent (NOI): A Notice of Intent is required for initial installation of any Sand or Drift fencing. Should new or additional timber supports be required for repair or maintenance of an existing fence a NOI is required. Where, due to erosion, the timber piles or posts must be moved or relocated, prior review of the proposed work and permitting is required.
b) Amended Order of Conditions: A request for an Amended Order may be filed in the event that damage occurs to a fence with a previously issued Order of Conditions which has not been closed by issuance of a Certificate of Compliance, and may include repair, including relocation of all or part of an existing fencing system.
8. Construction Specifications and Protocol for Sand Fencing:
Sand fencing offers a less invasive approach to dune restoration than the more substantial serpentine fence. This, when combined with a nourishment and replanting plan, will provide the coastal property owner an effective option for protecting an eroded bank or dune. The expense of sand fencing is considerably less than installing a drift fence, and its lighter construction may be less damaging to the beach during installation.
a) Placement: Dune restoration by means of sand fencing should take place as far landward as possible. A second or third, optional, fence may be installed up the unvegetated fore dune slope providing additional sand accumulation.
b) Materials: Sand fences should be made of wood slats, connected by wire and having a 50-50 ratio of open space to slats. (24” rather than 48” height will likely last longer due to less wind resistance while collecting a similar volume of sand.) The rolls should be attached to the posts with staples, with additional tie-wraps as desired. 4” x 4” rounded posts should be used if the area may be inundated with waves. Otherwise a lighter post may be used.
c) Construction: Posts should be set at or within several feet seaward of the toe of the dune scarp, 8’ apart. Posts should be dug five (5) to six (6) feet in the sand, and more if the fence is in a high-energy area. Each section of fencing between posts should have two removed or “missing” pickets, so as to create an opening in the fencing to accommodate birds and animals.
9. Construction Specifications and Protocol for Drift or Serpentine Fencing
a) Placement. In general, the edge of the drift fencing closest to the water shall be placed well above the mean high tide line and no more than six (6) feet from the toe of the bank. Plans submitted should delineate all resource areas and the location of all pilings.
b) Materials.
i. Timber pilings used to anchor sections of fencing shall preferably be 6-8" in diameter and shall not be longer than 10’.
ii. Slats shall be no more than 2”x3" and front braces and fence spans shall be no larger than 2x4 lumber, fence sections shall be 6' to 10' long, having a 50-50 ratio of open space to slats. Each fence span shall contain at least one "missing" slat, leaving a gap of at least 7.5" in the fencing (to permit movement of birds and other animals).
c) Construction:
i. All wooden materials to be used in any fencing shall be branded or permanently identified by a method approved by the Commission with the assessor's map and parcel # for the property where the fence is to be installed. Each fence shall be constructed so that the identifying information is on the landward side of the fence. Format for marking the wooden materials shall be map # hyphen parcel # (i.e. 23-1).
ii. Fence sections shall be assembled off site and brought to the beach location where the fence is to be erected;
iii. All pilings shall be individually dug with small excavator, at six feet deep; fence sections shall be bolted to pilings with slats on the water side; fence sections may be secured on the landward end by installation of a bracing member across the landward side. Fence sections shall not be trenched into the beach.
10. Construction specifications and Protocol for Biomimicry Sand Collection “Matrix” System.
Biomimicry is an adjustable, low profile sand restoration system consisting of thin cedar shims designed for use on coastal beaches during winter storms. No heavy equipment or excavation is necessary with this system. This matrix or system mimics the performance of native beach vegetation to collect and stabilize sand being transported by ocean storm energy.
a) Placement:
i. The shims should be inserted 3-4 inches into the sand, spaced randomly 10-14 inches on center (facing the water), leaving 10 inches exposed. Make certain the shims are dry before installation.
ii. The overall matrix pattern of random shims is between 4-6 feet wide.
iii. Matrix lines should always be installed parallel to the shoreline.
iv. Matrix lines can be spaced 15 feet apart to restore beach elevations.
b) Materials: Thin wooden shims, 14 inches long.
c) Construction:
i. This system can perform as a stand-alone or in parallel with newly planted beach grass, contributing to performance, pending plant maturity.
ii. The biomimicry system* shall be removed prior to April 15th and may be re-installed after Columbus Day pending approval by the Commission.
11. Deposition and Mitigation: Every fencing project except for biomimicry shall include beach nourishment. Every Notice of Intent shall specify the amount of sand to be deposited at the site and shall identify the source from which the nourishment material will be obtained. The nourishment material must be clean sand free of debris or waste and should be of a compatible grain size to the native beach material at the site. (Note: if sand which is of smaller grain size than the native material is used, the lighter sand will wash away sooner.)
The amount of nourishment material required for each project shall be determined on a case-by-case basis and will depend upon the topography of the site and the adjacent areas. In general, it is recommended that the applicant fill the area between the fence and the dune or bank to at least one-half the fence height, or a minimum of two feet above existing grade, whichever is greater. In addition, where the distance between the fence and the mean high-water mark is fifteen feet or more, then the applicant is required to deposit sufficient material to mirror the existing beach profile.
12. Vegetation: Every fencing project shall include planting of American Beach grass between November 1 and April 1 following completion of the installation or repair of the fencing. Planting holes should be dug at least 6 inches deep, randomly spaced 10-12 inches apart. Three culms (roots) are placed in each hole and covered with sand. It is recommended to plant in the greatest density in the landward section and decrease the spacing of plants in the seaward direction. The best results have been found with two applications, one in late spring within 30 days of planting, but before April 1, and another application in late summer or early fall. For further information, see: Coastal Dune Protection and Restoration, Marine Extension Bulletin, Woods Hole Sea Grant and Cape Cod Cooperative Extension, December 2008, and Beach Nourishment, MassDEP’s Guide to Best Management Practices for Projects in Massachusetts, March 2007. Attachments
13. General Regulations applicable to all fencing projects.
a) All projects shall specify dates for commencement and completion. All projects may only begin after Columbus Day and must be completed prior to Memorial Day, provided however that the project area is clear of nesting shorebirds as confirmed by the conservation agent or her designee.
b) All construction equipment shall only access the site from the beach, and only travel along the beach below the mean high tide line. Absent a showing by clear and convincing evidence that access to the coastal bank across the applicant’s property is impossible, no sand shall be trucked or transported to the site down the beach. All sand shall be brought to the site from the top of the bank at the applicant’s property.
c) Any substantial beach restoration requiring the hauling of materials other than sand from town landings across public and private beaches will be conducted exclusively from Columbus Day to April 15th. Substantial projects are those requiring over two days to haul materials.
d) Beach construction and restoration work shall not be performed on weekends or holidays, nor before 8:00 a.m. or after 6:00 p.m on weekdays.
e) Properties between the public access point for the project and the project locus shall be considered abutters and shall be notified of any substantial beach restoration projects in the same manner and at the same time as other abutters.
f) Construction debris shall be removed at the end of each day and the access route shall be left backbladed to a normal grade.
g) Application for Construction or Maintenance of a Sand or Drift fence shall constitute agreement by the property owner to reimburse the Town for the cost of clearing away any debris generated from the property owner's fence.
h) Where fencing becomes ineffective due to storm damage, erosion or other cause, it must either be promptly repaired or removed at the property owner’s expense.
i) Where fencing does not exist on an adjacent property, the fencing erected for the applicant shall be no closer than 25 feet to the abutter’s property line; where fencing exists on adjacent properties, new fencing shall be aligned with existing fencing.
j) Owners of lots which have less than 100 feet of beach frontage may be approved for fencing construction and/or restoration projects which do not comply with these general regulations, by special permit from the Commission.
k) It is the responsibility of the project proponent to obtain consent to traverse private property as may be required by property owners.
15. Penalties for non-compliance: When an instance of non-compliance is first discovered by the Commission or brought to the Commission’s attention, the Commission shall first give written notice to the property owner with a request that the property be brought into compliance within two weeks. If compliance is not obtained, the agent shall issue a $50.00 citation and require compliance within two weeks. If compliance is not obtained, penalties shall be assessed at the rate of $50.00 for each day, or part thereof, that the violation continues. Each violation shall be treated as a separate offense.