Sunset Ridge’s Homeowners Association Guide To Erosion Control

Is your house getting closer to the lake each year as your shoreline erodes?

Several factors contribute to this type of erosion Terrestrial Forces-slumping, sliding, soil creep, frost action, and wind

action Aquatic Forces-raindrop splash, sheet erosion, rilling, gullying, wave action, long

shore drift, and ice push Human Activities-clear-cutting of forests and shorelines, increasing and concentrating

stormwater runoff, agriculture, urbanization, and construction

First, step back, and determine the cause and extent of shoreline erosion at your lake

Sunset Ridge’s Primary Erosion SourcesWave ActionIce Flow

Methods of Erosion ControlThe three types of standard erosion control areVegetativeStructuralCombination of Vegetative and Structural

None of these methods is right for all situations.

It is important to match the type of erosion, and lakeshore environment to the control.

Vegetative erosion control is the use of native plants to stabilize the soil near the shoreVegetative – Advantages Increased spawning ground for fishAdequately disperses wave actionSoil and fertilizers are filtered through buffer strip, so less

ends up in the lake.Ducks favor this type of habitat – less food source for geese. Vegetative – DisadvantagesIncreases chance encounter with water snakes, ticks.

Does not provide “neat” shoreline view with park-like grass. Difficult to establish, high mortality of plantsRequires monthly maintenance for first three yearsNot Permanent – can fail

Riprap – Advantages Provides some structure for smaller fish/crayfish species. May prevent further erosion of site, if correctly installed. May provide immediate erosion control – reduced wave action Permanent –under normal circumstances will last 7-10 years.

Riprap– Disadvantages Riprap protects only the land immediately behind the barrier, and not

the adjacent areas. In fact, erosion may increase by wave reflection from the structure.

Riprap does not reduce water temperature, or filter soil from the land above the lake.

Riprap does not maintain natural look of the lake. Lakes with a riprap shore are less likely to have ducks or geese –

waterfowl like to be able to walk out of water. Requires 404 permit from Corps of engineers / 401 permit from DNR.

Structural erosion control involves building either a sea wall or the placement of rock riprap.

Combination of shoreline erosion control uses both of the previous methods.

Combination– AdvantagesImmediate erosion control, with future benefits of

vegetation.   Combination– DisadvantagesMost expensive, since you have to do both riprap

and plantings.

Recommendations for Sunset RidgeProposal One: Rip Rap would be installed along 792 lf of

shoreline, leaving the beach area as is. The application of rip rap would extend 7’ in width and be approximately 18” deep. The detention pond is filled with invasive cattails. FRE would herbicide the species and install 3500 native plugs. We are hoping the Army Corp. will accept this as the “native development” component eliminating native plantings along the shoreline and providing the HOA a manicured appearance and interesting plant species in the detention pond.

Mobilization/Construction SequencingDiscovery and Cleaning of detention pond

outletPlant 3500 plugs in detention pondKey-in and install GTX 160 filtration fabric to

protect existing soils from further erosionInstall Rip Rap 8-18”Landscape restoration

Native Plantings/Plugs

Native Plugs

Recommendations for Sunset Ridge

Proposal Two: Stabilization using outcroppings, rip rap and native development of detention pond.

In addition to the rip rap installation described above; 7 locations would have 20’ long runs of Rosetta Stone outcroppings installed. The outcroppings would be two tiers high (15”).

Rosetta Stone

Rosetta Stone Installed

St. Mary’s

Elysian HOA

Natural Colored Rip Rap

Spring 2010 Sunset Ridge showcases a new protective and aesthetically pleasing shoreline. Timeline from Army Corp

Permitting to Authority Approval 7 months.