Regulate the Type of Development Allowed
Case Study:
- Maine's Restrictions on Building Size
- Rhode Island Bans New Development and Public Infrastructure on Barrier Islands
Overview:
Regulating the type of development allowed along the shore can be an indirect way to deter the need for shoreline armoring. For example, restrictions can be placed on building size to ensure only smaller, less costly structures are erected in erosion hazards areas. Smaller structures are easier to relocate when retreat is needed and not as expensive to replace if they succumb to erosion. Similarly, restrictions can be placed on the type of construction methods/materials used to ensure the structures would be mobile and be able to be relocated when needed.
Other development restrictions could include requiring larger lot sizes to minimize the number of structures allowed within erosion hazards areas. Building density can also be controlled by limiting the allowable density for onsite sewer systems, or prohibiting the expansion of infrastructure (roads, utilities) to undeveloped or minimally developed shorefronts. Finally, state or local governments can prohibit the location of public buildings or buildings using public funds within erosion-prone areas.
Benefits: Can help deter development from high-risk erosion areas without prohibiting development entirely. By establishing development restrictions and density limits that would help avoid the need for shoreline stabilization structures, may help maintain natural shoreline dynamics in environmentally sensitive areas.
Drawbacks: Requires good scientific data to identify high-risk erosion areas and environmentally sensitive areas where different types of shoreline stabilization requirements should apply. Frequently have to grandfather in existing structures so the approach is only truly effective in relatively undeveloped areas or areas that have not undergone extensive shoreline hardening. Only indirectly addresses shoreline erosion and may not actually deter development. May be politically difficult to achieve since municipalities rely on property tax revenues from waterfront developments and would not want to limit development in these revenue-rich areas.
Case Study:
Maine's Restrictions on Building Size
Maine recognizes that many of its sandy beaches are eroding. The state also recognizes that seawalls, while they can be effective at protecting properties threatened by erosion, can also have many deleterious effects worth avoiding. Therefore, in addition to establishing construction setback lines, one way Maine helps deter the need for seawalls along sandy beaches is to limit the size and height of all buildings constructed in the coastal dune system. Smaller buildings can be relocated more easily and if destroyed, would not result in as significant a loss compared to if a much larger structure was lost to erosion. Under Maine's Coastal Sand Dune Rules (Chapter 355 (5)(D)), no building taller than 35 feet, or having a footprint greater then 2,500 square feet, can be constructed within the dune system unless the applicant can demonstrate "by clear and convincing evidence that the site will remain stable after allowing for a two-foot rise in sea level over 100 years."
Rhode Island Bans New Development and Public Infrastructure on Barrier Islands
Barrier islands, such as those along Rhode Island’s South Coast, are very dynamic areas. Rhode Island has classified its barrier islands into three categories based on the level of development present: Developed, Moderately Developed, and Undeveloped. Undeveloped barriers are essentially free of development while Moderately Developed barriers are essentially free of residential and commercial buildings but contain surfaced roads, recreational structures, and/or shoreline protection facilities. Developed barriers, on the other hand, contain residential and/or commercial/industrial structures, surfaced roads and shoreline protection facilities (Section 210.2). In the 1980s, the state banned any new residential and commercial buildings on Moderately and Undeveloped barrier beaches, 82% of the state’s barrier beaches, to prevent additional development in these high hazard areas (Sect. 120.2). To further deter development on all its barrier islands, the state also banned public infrastructure such as water, gas and sewer lines, on barriers islands.