SPRINGDALE CEMETERY

HILLSIDE RESTORATION AND STREAM CHANNEL STABILIZATION PROJECT

BACKGROUND

Springdale Cemetery is located in the City of Peoria, Illinois. It dates to 1854, and is one of the largest and most historic cemeteries in central Illinois. The cemetery covers 225 acres of rolling Illinois River bluffs and possesses many areas of natural beauty such as a small remnant of native tallgrass oak savanna. Since May 2003, Springdale Cemetery has been owned and managed by a partnership of the City of Peoria, Peoria County and the Peoria Park District. It is a State-registered Historic Site visited annually by thousands of people nation-wide. Hundreds of volunteers assist in maintaining the site and the natural areas within it.

To learn more about Historic Springdale Cemetery, click here.

Springdale Creek (also known as Turkey Creek) runs through the cemetery. The creek begins in Peoria Heights and empties into the Illinois River. Urban development in the land that drains to Springdale Creek, with a corresponding increase in hard surfaces from buildings and streets, has significantly increased the amount and rate of stormwater runoff to this stream. The increased water flow has created a stream powerful enough to scour away valuable land in Springdale Cemetery.

Springdale Creek has undergone increased streambank erosion, sedimentation in its channel bed and deterioration in the stormwater system for cemetery road drainage. According to an investigation undertaken in 2001 by the Peoria County office of the United States Department of Agriculture, the following conditions exist:

• The eroding streambank is threatening to damage a historical bridge and adjacent gravesites,

• The channel is “down-under and side-cutting” around ten existing concrete overfall structures installed 50 to 100 years ago, and

• Past efforts to control erosion have resulted in installation of several “grade control” structures and several places with concrete or stone walls. These existing structures are in various stages of disrepair and some of them are a total loss.

Soil lost from the hillsides and the banks of Springdale Creek is transported directly to the Illinois River. Sediment deposited in the Peoria Lakes has resulted in the loss of 77% of the volume that existed in 1903. Sediment does more than just reduce the water depth in Peoria Lakes; it also causes property damage, degrades water quality, damages fish habitat and impairs use of the Lakes for navigation or recreation.

Sediment originating from erosion is a form of nonpoint source (NPS) pollution. Unlike pollution from industrial and sewage plants, which is known as point source pollution, NPS pollution is caused by pollutants such as fertilizer, herbicides, and pesticides. These pollutants get deposited into lakes, rivers, streams, wetlands and groundwater.

The Illinois State Water Survey estimates that 40% of the sediment volume now filling the Peoria Lakes originated from just the 4% of the Illinois River watershed that discharges directly to the Lakes. The streambank and hillside restoration of Turkey Creek is just one step in addressing the sediment contributions from local sources that enter Peoria Lakes and the Illinois River.

THE PROJECT

The Project consisted of two parts – stream channel stabilization and hillside restoration. For the stream channel stabilization, a consulting engineer was hired to design Best Management Practices (BMPs) to stabilize the stream channel, and a contractor was hired to install the BMPs. For the hillside restoration, cemetery staff and volunteers undertook vegetative restoration on the steep wooded slopes adjacent to the stream.

For both facets of the project, there were two additional goals. They were to incorporate a variety of stream stabilization techniques (BMPs) to enable the project to be used as an educational site, and to provide practices that were compatible with the aesthetic requirements of the public in a historical cemetery.

Stream Channel Stabilization

The goal of stream channel stabilization was to reduce erosion and improve water quality by protecting the stream from the energy of water flowing downstream.  A number of Best Management Practices (BMPs) were installed to achieve this goal.

Gabion baskets are wire mesh cages filled with rock. They protect the stream from erosion by slowing the water, thus reducing the energy of the stream.

Rock riffles are another BMP. Rock riffles reduce the upstream slope and velocity of water flow. Rock riffles also improve fish habitat by increasing the amount of oxygen in the water.

Log revetments are used to protect eroding banks from the force of water in the stream. Both natural and man-made logs are used, and woody vegetation is planted behind them. Over time, the logs will disintegrate as woody vegetation grows to protect the streambank.

Rock barbs, which point upstream, are another BMP that reduces the velocity of water adjacent to a bank.

Hillside Restoration

Erosion occurs when runoff from rainfall flows down slopes because there is no vegetation or groundcover to slow down or absorb the water.  In the creek, the extra stormwater results in higher stream velocities that erode the banks of the stream.

The objective of hillside restoration is to increase the growth of vegetation that grows on the forest floor. Vegetation slows down stormwater runoff during rainstorms, which therefore reduces the amount of stormwater that flows into lakes, rivers and streams. Opening up the dense forest canopy by removing undesirable tree species allows sunlight to reach the ground so that vegetation can grow.

 The Results

The goal of the stream stabilization and hillside restoration project was to reduce the amount of sedimentation and non-point source pollution being carried to the Illinois River.  The Best Management Practices described in this brochure were installed in the summer of 2008.  Approximately 7 acres of hillside were restored, and over 1,900 feet of Turkey Creek was stabilized.  The chart below shows estimates of the amount of pollutants that will be kept out of the Illinois River by this project.

Estimated Pollutant Load Reductions

One of the benefits of hillside restoration is the growth of native species.  The seeds of beneficial trees and plants, such as this oak, germinate when sunlight and rainwater can reach the forest floor.

The project was funded, in part, through funds provided by the United States Environmental Protection Agency under Section 319 of the Clean Water Act, and distributed through the Illinois Environmental Protection Agency