IV. Shoreline change policy across the regions

IV. Shoreline change policy across the regions

Similarities among states can also be observed when considering “no alteration” policies and standards, which commonly include prohibiting armoring such as seawalls on ocean-facing shorelines (primary dunes in particular) and restricting construction or expansion of other structures, such as homes, on dunes and in flood hazard areas (velocity zones). In Rhode Island, hard structures and coastal armoring projects are prohibited along shorelines abutting conservation areas. South Carolina’s Beachfront Management Act states that it is the policy of South Carolina to “protect, preserve, restore, and enhance the State’s beach/dune system, the highest and best uses of which are declared to provide protection of life and property by acting as a buffer from high tides, storm surge, hurricanes, and normal erosion.” Texas has regulations that require property owners to remove encroachments from public beach easement areas (Higgin, 2008).

One important federal program that has played a role in shoreline change across all the regions covered by this report is the National Flood Insurance Program (NFIP). Created by Congress in 1968 through the National Flood Insurance Act of 1968, the program enables property owners in participating communities to purchase insurance protection from the government against losses from flooding. This insurance was initially designed to provide an insurance alternative to disaster assistance to meet the escalating costs of repairing damage to buildings and their contents caused by floods. Although the program was not established to cover shoreline change such as erosion, studies have shown demand for an expansion of the program to specifically cover erosion effects on private property (Keeler, Kriesel, & Landry, 2003).

Coastal construction standards under the NFIP have emphasized elevation rather than horizontal displacement. This has resulted in the use of substantial pilings—up to 20 feet above grade—in new or redeveloped communities along the Atlantic and Gulf coasts (Committee on Coastal Erosion Zone Management, Water Science and Technology Board, Marine Board, & National Research Council, 1990). Horizontal displacement is also required under the flood insurance program’s minimum standards, but only to the extent that new buildings in coastal high zones must be “located landward of the reach of mean high tide” and must not alter dunes or mangrove stands (44 CFR Section 60.3(e)).

A number of coastal states across the four regions examined in this study have established horizontal setbacks for new construction. These states have taken three basic approaches: natural resource protection buffer zones or setbacks, fixed setback lines, and average annual recession rate setbacks.

Management actions in the first category consist of limitations on development in wetlands or on dune systems in states such as Massachusetts and Wisconsin. The second category, fixed setback lines, is based on rules mandating no development within a certain distance of a reference feature (e.g., the seaward toe of primary dunes, a line of vegetation, the edge of an eroding bluff, the mean high water line, or a specified elevation contour). Due to the dynamic nature of these physical features, setback lines also move. One example of the use of fixed setback lines is the “coastal construction control line” established for each of Florida’s 24 sandy beach coastal counties based on the estimated inland reach of a 100-year storm event (Shows, 1978).

At least seven states across the four regions studied use “average annual erosion rate” setbacks to mark the minimum setback for new construction. Michigan and North Carolina impose a 30-year erosion rate setback on smaller structures; North Carolina also imposed a 60-year erosion rate setback on larger buildings.