STREAMS
The main stem of Shingle Creek begins in Brooklyn Park in northwestern Hennepin County and flows generally southeast to its confluence with the Mississippi River in Minneapolis. Shingle Creek is formed at the junction of Bass Creek and Eagle Creek, two of the major tributaries in the watershed. The river is approximately 11 miles long and drops approximately 66 feet from its source to its mouth. Palmer Lake is the only lake directly on Shingle Creek.
Several tributaries enter Shingle Creek as it flows through the watershed. A major tributary is Ryan Creek, which originates as the outlet of Ryan Lake in Minneapolis and joins the main stem of Shingle Creek 1.2 miles upstream of the outlet in northeastern Minneapolis. The three basins of Twin Lake drain most of the central portion of the watershed and outlet into Shingle Creek through a channel between Lower Twin Lake and Ryan Lake. Bass Creek and Eagle Creek drain most of the southwestern part of the watershed before forming Shingle Creek. Other tributaries include Pike Creek in Maple Grove and Twin Creek in Brooklyn Park and Brooklyn Center.
The central portion of the West Mississippi watershed is drained by Oxbow Creek. The creek flows in an easterly direction and then heads north, eventually outletting to the Mississippi River. The southern portion of the watershed is drained by the man-made Edinbrook/Century Channel, which runs from TH 169 to Mattson Brook and from there to the Mississippi River.
Stream Monitoring
The Shingle Creek and West Mississippi Watershed Management Commissions annually monitor water quality in the lakes and stream of the watersheds. The Commissions’ technical staff obtains most stream water quality data.
Water quality is related to the volume of water flowing to and through the streams draining the watershed and is influenced by the amount of precipitation received and the type of precipitation events. 2006 was a below average precipitation year. The timing of events and rainfall intensity also play a part in determining water quality. This annual variability is why on-going, long-term monitoring is necessary to determine what is an actual trend and what is just natural variation.
The Commissions’ 2006 primary stream monitoring program was conducted in two locations. The 2006 outlet-monitoring site was located on Shingle Creek at 45th Avenue. This site was designated as SC-0 and collects drainage from about 41 square miles, or 92% of the watershed. The upper watershed site was designated Site SC-2 and collects drainage from about 22 square miles, or 50% of the watershed. It was located on Shingle Creek upstream of Zane Avenue near the Brooklyn Park-Brooklyn Center border.
Site SC-1 is located on Shingle Creek at Queen Avenue near the border between Minneapolis and Brooklyn Center. Site SC-1 collects drainage from about 31 square miles, or 70% of the watershed. The United States Geological Survey (USGS) maintains this site as part of the USGS National Water Quality Assessment Program. The Commission and the USGS collected storm event samples at this location up until 1999 when water quality monitoring was discontinued. The USGS continues to monitor flow at this site and monitored for chloride and conductivity in 2006. Flow and other parameters at this site can be monitored real-time at http://waterdata.usgs.gov/mn/nwis/uv?05288705.
The 2007 Water Quality Report provides more detail on the Commissions’ stream monitoring activites.
Water Quality – Shingle Creek
Shingle Creek 2-year 3-hour rain event
On August 19, 2009 the northern suburbs in the Shingle Creek watershed experienced a 2-year 3-hour rain event, receiving 1.8 inches in 3 hours. On that day, Brooklyn Park City staff took photos of Shingle Creek at the Village Creek development between Zane and Regent Avenues at the height of the event and Wenck staff took photos a few hours after the event. Since one of the Commission monitoring stations (SC-3) is just upstream of this development and the Crystal Airport rain gauge is nearby, this was a good opportunity to graphically and pictorially demonstrate stream “falshiness.”
One of the major difficulties in managing an urban stream is that they tend to be very responsive to precipitation events. Storm sewers efficiently carry runoff to the stream, which rises rapidly. The engineered shape of modified channels such as Shingle Creek conveys the stormwater rapidly downstream at high velocities. The stream level falls nearly as rapidly as it rose, often with small secondary peaks as stormwater ponds and other storage areas discharge later in the event. When the stream returns to much lower base flow, the engineered channel is usually overwide, and the stream depth can fall to only a few inches.
This “flashiness” can be destabilizing to streambanks. It is also hard on aquatic organisms as they may have few natural refugia left to shelter them from the sudden increased stream flows. Channels are engineered to efficiently carry high flows, and at low flows are very low or even dry. The flashiness of urban runoff is one of the key stressors in most urban stream biotic TMDLs, including Shingle and Bass Creeks.
Figure 1 is a storm event hydrograph that shows streamflow and precipitation starting at about 10:00 a.m. on August 19 through 11:00 p.m. Streamflow was recorded in cubic feet per second (cfs) at 15 minute intervals, and precipitation was recorded in inches per hour. A light rain started falling in the late morning, with about 0.2 inches received in about three hours. Flow started increasing in the Creek almost immediately, and the level logger at SC-3 shows a stream stage increase of about four inches. As the storm grew in intensity, 0.42 inches of rain fell in the first hour (noon-1 p.m.), 0.94 inches in the second hour (1 p.m. – 2 p.m.), and 0.41 inches in the third hour (2 p.m. – 3 p.m.). Streamflow increased from 4.7 cfs to 268 cfs in two hours, and stream stage rose another 3.4 feet. After 3 p.m. the precipitation tapered off and streamflow fell, but stayed at about 20 cfs for the next few days as upstream ponds, wetlands, and other storage areas discharged.
Figures 1 - 5
Pike Creek Channel Restoration Project
The Pike Creek Channel Restoration is an innovative bioengineering effort sponsored by the City of Maple Grove with assistance from the City of Plymouth and Hennepin County and design and construction management services provided by Wenck Associates and Kestrel Design Group. (Wenck
performed the hydrology, hydraulic, and foundation analysis, and provided construction management services; Kestrel prepared the drawing set and detailed the bioengineering vegetation approach.)
This project was named in a Shingle Creek Commission report that identified channel degradation throughout the watershed. The City of Maple Grove viewed the Pike Creek channel stabilization as a priority and elected to have an ecological design as the solution.
Pike Creek channel is approximately 1/4-mile in length between Hemlock Lane and Pike Lake, in an area that is almost totally developed. Stream flows range from no flow to 800 cfs, resulting in a change in water surface elevation from the channel bottom to approximately 4-5 feet within an hour of a storm, with water elevation receding rapidly. Resultant flow velocities exceed 8.5 fps.
Undercutting of stream banks from these high velocities resulted in slope stability and safety concerns for adjacent property owners.
Alternatives considered in the feasibility study included piping, hard armoring of the entire channel, and soil bioengineering. The City and the residents opted for the third alternative that attempts to reestablish the woodland diversity prior to settlement. Resultant deeper rhizophere, shade tree thinning, exotic species removal, and boulder toe installation on cut banks will provide a stable channel while allowing storm flows to pass. (An on-site modification to the project consisted of substituting rock cross vanes for proposed rock gabion basket structures as energy dissipaters. Field verification determined that rock cross vanes would provide a more aesthetic approach as well as create a more stable downstream plunge pool by concentrating flow into the center of the channel.)
Clearing, grubbing, rough grading and armament were completed by early spring; bio-vegetation treatments and seeding completed the project in June 2003. Photos of the project can be found on the Commissions’ web site.
The Pike Creek Channel Restoration is an innovative bioengineering effort sponsored by the City of Maple Grove with assistance from the City of Plymouth and Hennepin County and design and construction management services provided by Wenck Associates and Kestrel Design Group. (Wenck
performed the hydrology, hydraulic, and foundation analysis, and provided construction management services; Kestrel prepared the drawing set and detailed the bioengineering vegetation approach.)
This project was named in a Shingle Creek Commission report that identified channel degradation throughout the watershed. The City of Maple Grove viewed the Pike Creek channel stabilization as a priority and elected to have an ecological design as the solution.
Pike Creek channel is approximately 1/4-mile in length between Hemlock Lane and Pike Lake, in an area that is almost totally developed. Stream flows range from no flow to 800 cfs, resulting in a change in water surface elevation from the channel bottom to approximately 4-5 feet within an hour of a storm, with water elevation receding rapidly. Resultant flow velocities exceed 8.5 fps.
Undercutting of stream banks from these high velocities resulted in slope stability and safety concerns for adjacent property owners.
Alternatives considered in the feasibility study included piping, hard armoring of the entire channel, and soil bioengineering. The City and the residents opted for the third alternative that attempts to reestablish the woodland diversity prior to settlement. Resultant deeper rhizophere, shade tree thinning, exotic species removal, and boulder toe installation on cut banks will provide a stable channel while allowing storm flows to pass. (An on-site modification to the project consisted of substituting rock cross vanes for proposed rock gabion basket structures as energy dissipaters. Field verification determined that rock cross vanes would provide a more aesthetic approach as well as create a more stable downstream plunge pool by concentrating flow into the center of the channel.)
Clearing, grubbing, rough grading and armament were completed by early spring; bio-vegetation treatments and seeding completed the project in June 2003. Photos of the project can be found on the Commissions’ web site.