The National Park Service (NPS) wants to build a cobble berm in the water off the Beverly Shores shoreline to combat beach erosion, caused by man-made structures—like the Michigan City Harbor—which are diverting the normal flow of sand to the west.

That berm is the one of the alternatives—and the preferred one—included in NPS’s recently released draft Environmental Impact Statement for the “Shoreline Restoration and Management Plan” for Indiana Dunes National Lakeshore.

The public has until Nov. 13 to comment on the draft plan.

As NPS notes, “erosion is largely due to the natural movement of sand being obstructed by navigational harbors and shoreline structures, resulting in sand accretion (too much sand) in some areas and sand starvation (too little sand) in others. Sand dredging and artificial beach nourishment operations have been used as stop-gap measures, but this process is not sustainable and does not address the long-term problem of protecting this valuable shoreline.”

For the purpose of this plan the shoreline was divided into four sections (referred to as reaches) based upon sediment erosion and accretion: Reach 1, from Crescent Dune to the eastern terminus of Lake Front Drive in Beverly Shores; Reach 2, from Lake Front Drive to Willow Lane in Dune Acres; Reach 3, from Willow Lane to Shore Drive in Ogden Dunes; and Reach 4, from Shore Drive to the U.S. Steel impoundment in Gary.

The draft Environmental Impact Statement evaluates seven possible alternatives for reaches 1 and 2; for reaches 3 and 4, four alternatives including a no-action one. “All alternatives meet park purposes and objectives while protecting park resources by minimizing impacts, and are consistent with the legislative intent of Indiana Dunes National Lakeshore, applicable NPS laws, policies, and regulations,” NPS said.

Alternatives for reaches 1 and 2 include beach nourishment either mined from an upland source or dredged from a nearshore area, on an annual basis or every five years. The preferred alternative, however, would be the construction of a submerged cobble berm at approximately a 10-foot depth and running the length of Reach 1, in combination with the annual hydraulic placement of around 100,000 cubic yards of sediment from a dredged source east of the Michigan City Harbor.

That berm “would stabilize the shoreline downdrift of the Michigan City Harbor by reducing the quantity of sediment needed for beach nourishment, to enhance aquatic habitat by diversifying the nearshore substrate, and to improve erosion protection during storm events,” NPS said. Over a period of five years that berm would dissipate and its aggregate material would cover the clay lakebed, NPS added. Until it dissipates, the berm “would temporarily present a safety concern to draft vessels traveling near the shoreline,” NPS said. “Signs would be installed to warn the public of potential danger.”

Alternatives for reaches 3 and 4 include nourishment of various amounts on varying schedules. The preferred alternative is the placement every five years on Reach 3 of 370,000 cubic yards of sediment, dredged from an updrift location like the Bailly Generating Station uptake. That placement would take about six months and would run the entire length of Reach 3 west of the Burns Waterway Small Boat Harbor, “with an increase in beach elevation to approximately 12 feet above low water datum.”

A written copy of the draft Environmental Impact Statement for the Shoreline Restoration and Management Plan is available in three different formats. It can be found online at http://parkplanning.nps.gov/indu. A CD of the document can be requested by contacting (219) 395-1547. Hard copies of the document will be available for review at the Indiana Dunes Visitor Center at 1215 North State Road 49 in Porter, Indiana, and at Indiana Dunes National Lakeshore Headquarters located at 1100 North Mineral Springs Road in Porter, Indiana.

The best way to comment on the draft Environmental Impact Statement is to use the electronic form located at: http://parkplanning.nps.gov/indu. The 60 day comment period closes on Nov. 13. Comments must be postmarked no later than Nov. 13. If you cannot use the electronic form you may mail or drop off a hard copy comment form and/or letter to: Indiana Dunes National Lakeshore, Attention: Charles Morris, Environmental Protection Specialist, 1100 North Mineral Springs Road, Porter, Indiana 46304-1299

Funded through the Great Lakes Restoration Initiative, in collaboration with the Environmental Protection Agency and the Army Corps of Engineers, the National Park Service (NPS) has prepared the draft Shoreline Restoration and Management Plan to restore Indiana’s eroding beaches. This plan recommends a variety of possible methods for remedying erosion and damage to the National Lakeshore’s dunes and beaches.

The National Lakeshore includes most of the beaches along Indiana’s shoreline from Trail Creek in Michigan City to U.S. Steel in Gary. As described in this draft Environmental Impact Statement, the shoreline in this area suffers from erosion which threatens national park resources, recreation opportunities, homes, industry, and businesses.

“The draft Environmental Impact Statement has been prepared to provide scientifically-based alternatives for the restoration of natural sediment movement along the southern shore of Lake Michigan within and adjacent to Indiana Dunes National Lakeshore,” NPS said.

Posted 9/19/2012