The Kestner Waterfront Park is located within the city limits of Houghton, Michigan along Portage Lake. Due to its scenic location and ample facilities, the park is one of the most popular in the city. Facilities include a swimming beach, launch site for kayaks and sailboats, an extensive playground area, picnic tables, grills and a lakeside walking path. An RV park is located immediately to the west, and boat docking and launching facilities are located immediately to the east of the park proper. The park also has a pavilion and band shell, making it a prime location for many outdoor events and gatherings. A photo of the north side of the park is provided as Figure 1 below.
Figure 1 – Kestner Waterfront Park Figure 2 – Huron Creek in Park, September 2007
The primary goal of this project is to improve the channel of Huron Creek in Kestner Waterfront Park to provide slope stability and more attractive, naturalized streambanks. Huron Creek travels through the Kestner waterfront park for approximately 350 feet before flowing into the Portage waterway beneath a concrete walkway. Historically there have been repeated problems with the banks of Huron Creek washing out from erosion during storms. A severe storm in September 2007 caused several bank areas to completely fail (Figure 2) resulting in steep, undercut and unprotected slopes. Various methods have been used to attempt to stabilize the banks over the years including rip-rap, herbaceous plantings and erosion matting with lawn grass. Each method has eventually given way to bank erosion.
In an attempt to repair the banks and ideally stabilize them permanently, the City of Houghton is proposing to implement biotechnical stabilization along the bank areas in the park as shown in the attached Figure 3. The stabilization will consist of three components: (a) installation of rock-filled gabions at the toe of the bank slopes to protect against erosion during high flow events; (b) re-grading the bank slopes to grades of between 3H:1V and 2H:1V; and (c) planting the slopes and gabions with native trees, shrubs and grasses.
Essential Elements of Project
The following items describe the biotechnical stabilization method proposed by the City of Houghton:
Excavate slopes back to a shallower angle; 3H:1V where possible, otherwise 2H:1V given a buffer strip width of 12 to 18 feet.
Install two levels of stone-filled gabions at the toe of the slope. The bottom gabion is to be sunk into the creek bed to provide protection against undercutting. Both the top and bottom gabions are to be installed at an angle to provide against the potential for sliding. A typical cross-section of an improved slope is provided as Figure 4.
Plant native shrubs into bank on top of upper gabion to provide additional toe and bank stabilization. This measure, along with the lower gabion being sunk into the creek bed will help cover the gabions to add a more natural look to the creek while sufficiently stabilizing it. Figure 5 shows typical native shrub placement on top of the gabions.
Plant a mixture of native grasses, shrubs and trees within a 12 to 18-foot buffer strip along biotechnical stabilization areas. This will contribute to bank stabilization, help cover and prevent access to the gabions, and help create a more natural creek corridor. Planting locations and details are provided on Figures 6 and 7. Native plant species are included in drawing notes and an attachment.
The City of Houghton acknowledges that the Michigan Coastal Management Program generally does not support the use of “hard” shore protection such as gabions. However, after several tries at stabilization, and discussions with local experts such as Natural Resource Conservation Service (NRCS) representatives, it is our conclusion that hard stabilization at the toe of the banks is necessary for long-term success. Velocities of Huron Creek in the Kestner Waterfront Park can exceed those allowed as maximum for “soft” measures such as coir logs or lone vegetative stabilization. These high velocities can be attributed to steep topographies (surface slopes exceed 10%-15% in some locations) and a significant amount of urban development upstream.
This proposed project is also being completed in support of the Huron Creek Watershed Management Plan (MDEQ grant tracking #2006-0162) which is being funded by the Michigan Department of Environmental Quality. The Michigan Technological University (MTU) Center for Water and Society (CWS) is responsible for developing the watershed management plan. A watershed advisory committee (WAC) was formed in 2006 as part of the watershed management planning efforts. Since the Kestner Waterfront Park provides one of the few places in the watershed where visitors can “interact” with the creek, it is a goal of the Huron Creek WAC that this location be utilized to spread awareness of the creek and watershed management. The Huron Creek WAC has recommended that improving the banks of the creek would provide a healthy, visually appealing creek would and encourage support to protect and restore the remainder of the Creek. An interpretive sign describing the Huron Creek watershed and watershed health was installed in the park adjacent to the creek in 2007.
The MTU CWS has provided designs, calculations, cost estimates and drawings for submittal with this proposal as well as for inclusion in the watershed management plan.
Improvements to Huron Creek in the Kestner Waterfront Park have been suggested in the City of Houghton’s “Recreation Plan 2008– 2013” (see http://www.cityofhoughton.com/news/45.pdf).
Relationship to Existing Facilities
In the Kestner Waterfront Park, Huron Creek is located centrally between a popular swimming area and another small beach and boat launching area. After some storm events, eroded sediment and debris can be seen along the banks and discharging from the mouth of the creek into Portage Lake towards these areas. This can create visually displeasing conditions at these locations, as well as negatively affect the water quality.
Gabion materials and installation $48,000
Bank grading $15,000
Grass, shrubs, trees, fertilizer and installation $12,500
Erosion mat, stakes and installation $6,500
Local match for this project includes funds appropriated by the City of Houghton for the city recreation plan and in-kind labor.