Dock, pier and float rules in South Portland, Maine
Possibly, with Planning Board approval. South Portland's shoreland zoning requires Planning Board shoreland approval for any pier, dock or float extending over or below the high-water line, allows only one such structure per lot, and limits it to the size needed for its use. Docks in Portland Harbor also fall under the Portland Harbor Commission and state and federal permits, which we couldn't review.
| Town approval | Planning Board shoreland zoning approval [1] |
| Number per lot | One structure below the high-water line or in a wetland [2] |
| Size limit | No larger than necessary; temporary non-commercial docks in non-tidal waters max 6 ft wide [3] |
| Seasonal vs. permanent | Temporary = in the water less than 7 months in any 12; permanent = 7 months or more [4] |
| Buildings on a dock | Only if water access is an operational necessity; max 20 ft tall above the dock [6] |
| Permanent docks on non-tidal waters | Only if a temporary dock isn't feasible and a DEP permit is obtained [7] |
Town approval
South Portland regulates docks through the Shoreland Area Overlay District in the zoning ordinance. Any structure or use extending over or below the normal high-water line or within a wetland needs shoreland zoning approval from the Planning Board, rather than the Code Enforcement Officer [1]. The board must find, among other things, that the dock won't harm water quality, fisheries or wildlife habitat, public access, or existing commercial fishing or maritime activities. Docks are exempt from the shoreland building setbacks because they need direct water access [5]. Temporary and permanent piers and docks are even allowed in the Shoreland Resource Protection subdistrict.
Design limits
Only one structure extending below the high-water line or into a wetland is allowed per lot [2]. The dock must be no larger than necessary for its use; a temporary non-commercial dock in non-tidal waters can be no wider than 6 feet [3]. It must be built on suitable soils to control erosion, avoid interfering with beaches, and minimize harm to fisheries. New buildings on a dock are allowed only for operational necessity and can be no taller than 20 feet above the dock [6]; existing dock structures can't be converted to homes.
Seasonal vs. permanent
The ordinance defines a temporary dock as one in the water less than 7 months in any 12, and a permanent one as 7 months or more [4]. On non-tidal waters (ponds, streams), a new permanent dock is allowed only if the Planning Board finds a temporary one isn't feasible and you have a DEP permit [7].
Other permits we couldn't review
Most of South Portland's shoreline is tidal Portland Harbor and Casco Bay. Moorings and wharf or pier work in Portland Harbor are governed by the Board of Harbor Commissioners for Portland Harbor, whose rules we couldn't download for this review. State DEP (Natural Resources Protection Act) and U.S. Army Corps of Engineers permits generally also apply in tidal waters. Check with the Harbor Commission before planning a dock or float.
See how South Portland compares with 8+ other Maine towns on docks, piers & floats →
Next steps
- Contact the Portland Harbor Commission/harbormaster about harbor rules, moorings, and any channel or pier-line limits.
- Contact South Portland Planning & Development to start a Planning Board shoreland zoning application with plans and pre-construction photos.
- Apply for state DEP (NRPA) and U.S. Army Corps of Engineers permits as needed for work in tidal waters.
- Decide whether the dock will be seasonal (in the water under 7 months a year) or permanent, since that affects permits.
Common questions
- Can I build a dock in South Portland, Maine?
- Possibly, with Planning Board approval. Any pier, dock or float extending over or below the high-water line needs shoreland zoning approval from the Planning Board, and only one such structure is allowed per lot.
- What is the difference between a temporary and permanent dock in South Portland, Maine?
- A temporary dock is in the water less than 7 months in any 12. A permanent one is in the water 7 months or more. On non-tidal waters, a new permanent dock is allowed only if a temporary one isn't feasible and you have a DEP permit.
- How big can a dock be in South Portland, Maine?
- It must be no larger than necessary for its use. A temporary non-commercial dock in non-tidal waters can be no wider than 6 feet.
- Can I put a building on a dock in South Portland, Maine?
- Only if water access is an operational necessity, and it can be no taller than 20 feet above the dock. Existing dock structures can't be converted to homes.
- Are there other permits for a dock in South Portland, Maine?
- Probably. Docks in Portland Harbor fall under the Board of Harbor Commissioners, whose rules the page couldn't review. State DEP and Army Corps of Engineers permits generally also apply in tidal waters.
State and federal rules for docks and piers
DEP permit (Natural Resources Protection Act): Building, repairing or altering a permanent structure in, on or over a great pond, river, stream or coastal wetland needs a DEP permit. "Permanent" means the structure stays in place more than 7 months in any 12-month period. A seasonal dock that comes out each year generally isn't a permanent structure.
State shoreland minimums (your town's ordinance applies these):
- Only one pier, dock or wharf per lot, unless the lot has at least twice the minimum shore frontage.
- A temporary, non-commercial dock on fresh water can be no wider than 6 ft.
- A new permanent dock on fresh water is allowed only if a temporary dock isn't feasible and DEP has issued a permit.
- No living space on or attached to a dock.
State-owned bottom: Below the low-water mark in tidal waters and in great ponds, the bottom belongs to the state. Permanent structures of any size, and large temporary ones, need a lease or easement from the Bureau of Parks and Lands. Non-permanent structures under 500 sq ft don't need one.
Federal and harbor rules: In tidal waters, docks and floats also need U.S. Army Corps of Engineers approval. Moorings are handled by your town's harbormaster under local ordinance (38 M.R.S. §7).
What the ordinance says
- Sec. 27-1331(A)(1), Zoning (Code of Ordinances Chapter 27), p. 297
1. from the Planning Board for any proposed structure or use extending over or below the normal high-water line or within a wetland under this Article, for any special exception or project subject to site plan review under Article XIV of this Chapter or for any proposed subdivision under Chapter 24 of the Code; and
- Sec. 27-1322(D)(1), Zoning (Code of Ordinances Chapter 27), p. 280
No more than one structure extending or located below the high-water line of a waterbody or within a wetland is allowed on a single lot.
- Sec. 27-1322(D)(5), Zoning (Code of Ordinances Chapter 27), p. 281
The facility shall be no larger in dimension than necessary to carry on the activity. A temporary pier, dock or wharf in non-tidal waters shall not be wider than six (6) feet for non-commercial uses.
- Sec. 27-201 Definitions, Piers, docks, wharves, Zoning (Code of Ordinances Chapter 27), p. 63
Temporary: Structures which remain in or over the water for less than seven (7) months in any period of twelve (12) consecutive months. Permanent: Structures which remain in or over the water for seven (7) months or more in any period of twelve (12) consecutive months.
- Sec. 27-1322(B)(1), Zoning (Code of Ordinances Chapter 27), p. 276
The water body, tributary stream, or wetland setbacks listed in Sec. 27-1322(A)(2) above shall apply neither to buildings that require direct access to the water body or wetland as an operational necessity, such as piers, docks, wharves, bridges, retaining walls, and other similar structures, nor to other functionally water- dependent uses.
- Sec. 27-1322(D)(8), Zoning (Code of Ordinances Chapter 27), p. 281
Structures built on, over or abutting a pier, wharf, dock or other structure extending beyond the normal high-water line of a water body or within a wetland shall not exceed twenty (20) feet in height above the pier, wharf, dock or other structure.
- Sec. 27-1322(D)(9), Zoning (Code of Ordinances Chapter 27), p. 281
New permanent piers and docks on non-tidal waters shall not be permitted unless it is clearly demonstrated to the Planning Board that a temporary pier or dock is not feasible, and a permit has been obtained from the Department of Environmental Protection, pursuant to the Natural Resources Protection Act.