The Highland Ravine Stabilization Project is located in the Highland neighborhood of Saint Paul. The neighborhood sits atop a bluff area upland from the Mississippi River. The project area is 50 acres that includes a ravine with numerous gullies that rises from Lexington Avenue to Edgcumbe Road. The ravine is surrounded by primarily residential properties in both the upland areas and at the base of the ravine. A portion of the ravine is located within the City of Saint Paul’s Highland Park.
In response to citizen concerns about large volumes of stormwater runoff and sedimentation from the ravine that have damaged private property, a feasibility study of the ravine was conducted in 2011. The objectives of the study were to 1.) Identify and quantify the problems of flooding, erosion and water quality, 2.) To identify the causes of these problems and 3.) Recommend solutions. The study identified two primary gullies of concern. The recommendation was to first stabilize the gullies by regrading the slope and creating rock check dams to slow water down and secondly, restoring the woodland with native vegetation that will help stabilize the soil. The third and final recommendation is to construct BMP features in the upland area that will minimize runoff and increase storm water storage and infiltration.
The project area includes a natural steep bluff and ravine area. Because of the topography and land use in the area, runoff moves very quickly on its way to the Mississippi River. Runoff carves into the land along its most direct path downhill creating gullies. This process causes erosion, flooding and the delivery of pollutants to the Mississippi River. Because the area is primarily residential properties, storm water runoff has also resulted in property damage.
Project Scope of Work
In late 2012, CRWD commenced the Highland Ravine Stabilization Project to fulfill the first two recommendations of the earlier feasibility study: 1) stabilize the ravine area by regrading and installing rock check dams in the gullies to slow runoff down and 2) restore the woodland area with native vegetation. In 2013, CRWD has completed field assessment and survey work and identified all gullies in the project area. The stabilization design includes 1-foot high rock check dams along the length of the gullies, pipes at the bottom of the gully channels to bring water safely down the slope, and a stormwater basin at the bottom of one of the ravines. By early 2014, CRWD anticipates completing design of the stabilization project and securing easements. Construction of the project is planned to be take place and be completed in 2014.
CRWD is also working with individual property owners in the design and implementation of water-friendly landscapes that manages residential rainwater on-site by redirecting downspouts to flat vegetated areas including rain gardens.
Public Education and Outreach
Because most of this project resides on privately owned land, communication with property owners and neighborhood residents has been essential. These stakeholders have provided feedback throughout the planning and design process at multiple meetings. Addressing the concerns of property owners and residents has been and will continue to be vital to the implementation and future success of the project and we greatly appreciate all of the cooperation we have gotten from the homeowners.
The construction budget is estimated to be over $200,000. Funding is provided by CRWD and through a State grant from the Clean Water Fund.