Workshop Purpose

To provide coastal managers with the latest scientific data and management tools relating to the siting and construction of small docks and piers.

Key Points from Panel on Ecological Impacts from Dock and Pier Construction

• Shading from dock/pier construction reduces the density of submerged aquatic vegetation (SAV) growth directly under structure. Height is the most important variable, with docks of 10 feet and higher significantly reducing impacts. Spacing between planks does not noticeably affect plant growth. Orientation is also a factor, with north/south orientation being optimal.
• While it is clear that docks affect SAV growth, it is likely that other factors such as vessel propellers and land-based nutrient inputs also contribute to SAV loss.
• Shading has similar impacts on salt marsh vegetation. For a four-foot wide walkway, heights of 4 ˝ feet over Spartina patens and 4 feet over Spartina alterniflora seem to minimize impacts, but additional research is necessary. It is not currently known what the threshold is for shading impacts for vegetation, nor is there an easily implemented means of calculating shading based on the various parameters such as height, width and orientation.
• Chromated copper arsenate (CCA) is commonly used to pretreat wood for placement in the marine environment. CCA treated piles and bulkheads can leach copper in both controlled lab experiments and in the marine environment. The effect of copper on marine organisms in the field is localized, with impacts detected only within 3 meters. While evidence exists that bulkheads of CCA material have impacts on water and sediment quality, particularly in poorly flushed areas, similar evidence has not been developed for pilings either in salt marsh sediments or in tidal waters.
• Floats on the bottom of docks should not be flat. Flat floats cause hydraulic pumping that can cause erosion under the float and can alter sediment size effectively changing habitat.

Key Points from Panel on Practical Approaches to Managing Docks & Piers

• Developing local dock and pier siting plans based on demand data and the identification of sensitive resources is a good approach. Such local plans can be used to strengthen state authorities.
• It is important for management programs to establish standards for evaluating dock and pier siting and construction. In addition to ecological thresholds, aesthetic, recreational, and navigational standards are also important.
• Pleasant Bay Resource Alliance divided the Bay into 26 geographic subsections and surveyed each area for biological, environmental, and human use factors. A sensitivity scale was developed for each subarea. The sensitivity scale was used to determine where additional docks and piers would be allowable subject to performance standards.

Key Points from Panel on Best Management Practices of Docks and Piers

• The primary material used today for docks and piers is CCA, but new innovations include steel-reinforced plastic and recycled plastic.
• Docks and piers should be designed based on specifics of each site (natural resources, wind, waves, water depth, boat wakes, current, ice, and soil).
• Fewer piles generally cause fewer impacts.
• Designers of public facilities need to design to Americans with Disabilities Act (ADA) standards (includes slope, turnarounds, and width).
• Dock and pier permit conditions need to have adequate flexibility to take into account safety and site practicality.

Research/Management Needs Identified

• Very little work has been done on the cumulative impact of docks and piers.
• A buildout analysis for a sample town would be a good tool to demonstrate the extent of dock development allowable under current regulations.
• The state’s Chapter 91 licensing program should encourage raising the height of docks and piers to allow access under structures, rather than encouraging stairway access. Stairs create additional shading impacts and concentrate foot traffic.
• The eelgrass/dock model by Burdick/Short is limited to a discrete number of conditions. It needs to be expanded to take into account turbidity, current and depth as well as other combinations of height, width and orientation.
• A similar model needs to be developed for predicted shading to salt marsh vegetation.
• We need to clarify the definition of "significant" resources under the Wetlands Protection Act to clarify its application.
• Need to evaluate optimal height, width, orientation and length of docks to minimize ecological impacts.
• Municipalities are in need of guidance materials/training on dock and pier permitting.

Massachusetts Regulatory Programs that Relate to Dock and Pier Construction

• DEP regulates navigation and public access through the issuance of Chapter 91 licenses, pursuant to the Waterways Regulations at 310 CMR 9.00.
• Massachusetts General Laws Chapter 91, the Public Waterfront Act, requires state authorization for the construction of docks and piers extending below mean high water. The Waterways Regulations include a provision that authorizes municipalities to license non-commercial docks and piers affiliated with residences using a three-step process: 1) designate a local official, 2) establish one formal access point to all water bodies, 3) direct all fees to waterways. All local permitting programs must be consistent with the Waterways Regulations under Chapter 91.
• Designated Areas of Critical Environmental Concern (ACEC) that currently lack a comprehensive resource management plan have a moratorium on the licensing of new privately-owned docks and piers.
• Municipalities may develop state-approved municipal harbor plans to customize Waterways Regulations to suit their specific needs.
• The Waterways Regulations contain an underutilized but potentially powerful provision that allows a municipality to develop a "formal area-wide policy or plan" that assigns priorities to competing uses in a waterway. Once a town approves such a policy or plan, it would generally govern DEP Waterways licensing of private docks and piers. The Wetlands Protection Act (WPA) regulates docks and piers in wetlands. Temporary (less than one year) impacts can be approved. The WPA cannot allow "adverse impacts" to shellfish resources if the shellfish resource is "significant." "Significant" is defined as mapped by Conservation Commission or the Division of Marine Fisheries.

Tools that Municipalities Can Use to Manage Docks and Piers

• Development of a state-approved Municipal Harbor Plan that can be enforced through the Chapter 91 license process.
• The Department of Environmental Protection is developing a guidance document on docks and piers, outlining the science, management practices, and implementation strategies. The guidance should be available in 2001. Workshops will be held at that time.
• Incentives to encourage landowners to share docks could include fast track permitting or flexibility in meeting standards.
• The Division of Marine Fisheries and town shellfish officers are developing maps of shellfish habitat. These maps, which will be available both digitally and in paper format, should be completed by next summer (2001).
• Municipalities can regulate anything that the state doesn't already regulate. If the state does regulate an issue, a municipality can strengthen the regulation. All by-laws must address the police powers of health, safety, and welfare. Dock and pier regulation is sometimes difficult to justify under police powers; Chapter 91 generally regulates to protect the public trust interests in waterways. Municipalities can regulate docks and piers under local wetland by-laws. By-laws should have a clear connection with resource values.
• Municipalities cannot enforce the public trust doctrine. Only the state is vested with that responsibility.
• See last bullet in previous section.

Resources Available for Further Information

• Dock Design with the Environment in Mind: Minimizing Dock Impacts to Eelgrass Habitats, CD ROM, Dave Burdick and Fred Short. Contact: Marie Polk, NH Sea Grant, Kingman Farm/UNH, Durham, NH 03824; (603) 749-1565, [marie.polk@unh.edu]. The cost of the CD is $5 plus $1 for shipping. When ordering, ask for Item # UNHMP-V-SG-98-18
• Video of Dock and Pier Workshop, 2001. Contact: Tracy Crago, WHOI Sea Grant Office, Woods Hole Oceanographic Institution, Woods Hole, MA 02543, (508)457-2000 x2665, [tcrago@whoi.edu]. Cost: $20 per 4-video set. Quantities are limited and orders will be filled on a first come, first served basis. Workshop videos are also available for loan by CZM. Contact: CZM Information line (617) 626-1212.
• The Waterfront Construction Handbook: Guidelines for Design and Construction of Waterfront Facilities, Maine Coastal Program, 1997. Contact: Lorraine Lessard, Maine Coastal Program, (207) 287-1486, [lorraine.lessard@state.me.us]
• Guidelines and Performance Standards for Docks and Piers in Pleasant Bay, Pleasant Bay Resource Management Alliance, 1999. Contact: www.pleasantbay.org. The guidelines can be found on the programs/projects page, listed under shoreline structures.
• Reprints of review articles pertaining to the ecotoxicology of chromated copper arsenate (CCA), including: Effects of Chromated Copper Arsenate (CCA) Pressure Treated Wood in the Aquatic Environment, Weis and Weis, Ambio Vol. 24 pp 269-274. Contact: Pete Weis [weis@umdnj.edu]
• Dock and Pier By-laws for towns of Bourne and Falmouth. For the Bourne by-law, contact: Matt Boulanger, Conservation Agent, 24 Perry Ave, Buzzards Bay, MA 02532, (508) 759-0625. The by-law can also be found on the Conservation page of the town’s web page, www.townofbourne.com. For the Falmouth by-law, contact: Conservation Commission, 59 Town Hall Square, Falmouth, MA 02540, (508) 548-7611. The cost of reproducing the Falmouth by-law is $8 per copy.
• MA DEP Dock and Pier Guidance, expected publication date is spring 2001. Contact: Sharon M. Pelosi, DEP, One Winter Street, Boston, MA 02108, (617) 556-1104.
• Guidance for Dock and Pier Construction in ACECs and Ocean Sanctuaries, Massachusetts Office of Coastal Zone Management, 1988. Contact: CZM Information line (617) 626-1212.