From the regulations promulgated July 1, 2019
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.
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.
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.
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.
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.
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.
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).
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.
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.
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.
- A well vegetated bank provides significant resistance to storm damage; therefore, the Commission requires extensive planting of the coastal bank as part of any erosion control project, including re-planting as on-going maintenance in all projects.
- In the case of an “erosion control” project permitted under these regulations, these standards must be met by a showing,by substantial evidence, that a sufficient quantity of beach nourishment and “sacrificial” sand will be provided as part of the project to ensure that the movement of sediment and sediment supply will not be adversely affected by the project.
- A model order of conditions is attached to these regulations and incorporated herein. No waivers from these required orders shall be allowed except upon clear and convincing scientific proof that the proposed waiver will improve the ability of the coastal bank to provide storm damage protection, prevent flooding and contribute sediment to the littoral system.
- Escrow agreement: Every erosion control project shall include a requirement that the property owner establish an escrow account with the Town of Truro in accordance with the requirements of the Model Escrow Agreement attached to these regulations and incorporated herein. This agreement allows the Conservation Commission to remove any project as to which the owner fails to perform ongoing maintenance as required by the Commission.