Red Mill Pond Section 506 Restoration of

Naturally Steep Slopes with Spring & Seep Habitats

Pre-Project w/Dam Old saw mill dam impounded the very headwaters of the Little Calumet River. The impoundment flooded out a knob & kettle valley, which was riddled with springs & seeps that fed the Little Calumet. The saw mill dam was put in around 1875 and rebuilt several times, in which the impoundment naturalized into a hemi marsh. Naturalization occurred before invasive species were present within the region, so the resulting hemi marsh is of high floristic value, as well as the surrounding mesic forest (albeit secondary growth forest).

Dam Crest

Dam Removed Removal of the dam was preceded by creating a temporary by-pass channel, which dropped the pool to the level that would be resultant of removing the dam. Once the pool area sufficiently dried out, which it never really did due to the high volumes of groundwater discharge, the new stream channel was formed and lined with indicative substrates that were sampled from downstream reaches.

The revealed seeps were packed with small cobble and large gravel only. The slopes were steep, ranging from 1:1 to 1:3.

Main Known Seep

Many Unknown Seeps

Biodegradable Straw Matting The straw matting was used because plant growth was suspected to be of high rate the following spring due to the impeccable hydrology and natural till soils. This thin matting would support this situation. The cobble packed seep was left uncovered to promote faster vegetation growth.

Coir Coconut Logs The coir coconut logs were added to spread sheet flow over the area that would become a fen. The logs were also used in a large spring & seep that was of shallow gradient to prevent head-cutting during the period before plants were established.

The use of riprap or additional rock in this system would have created an adverse affect to the wetland plant communities and hydrologies, which is the opposite of ecosystem restoration. All materials used had a longevity period sufficient enough to last until plant root matrix systems took over.

Small Batch of Native Plants Nearly 50 species of wetland plants were plugged into the designated hydrogeomorphic zones: fen, seep, marsh, stream. The contract required both genetic specificity and for the plants to exhibit a robust vigor, as you can see in the photo they are extremely healthy. The contract would allow rejection of poor plant stock.

Plants Begin to Take Over As expected, the native plugs, with supplemental seeding of annuals, began to cover the ground in mid June. Main Known Seep

Big Flat Seep

Plants in July Quick growth with appropriate species selection in terms of genetics and hydrology preferences.

Plants in August The steep cobble and gravel seep is completely shrouded in native plants, as well as the areas of bank that have steep slopes (1:1).

Main Known Seep

Flat Seep

First Fall No signs of rilling, headcutting or erosion anywhere within the site, and there was continuous water flow out of the seeps and the site experience several good sized floods.

Only Project Failure Certain project engineers insisted on riprap under the bridge, because that is just how this is supposed to be built. I had no examples to show otherwise, so now I am thankful for this example. See next slide…

RipRap & Geotextile

To date, the bottom 3rd of the riprap has fallen into the stream. I instructed the non-Fed sponsor to remove riprap from stream as they fall in and cut the fabric back as it becomes exposed. Now native plants are filling in these areas where the fabric is being cut out.

Bank Toe Under Bridge

Adjacent to RipRap Under Bridge