Central Draw Overflow
The East Ravine subwatershed incorporates the preferred path for the Northern subwatershed overflow to provide an outlet to the Mississippi River. The Central Draw Overflow Project is intended to provide principal and emergency outlet capacity for this land locked watershed under existing conditions. The Central Draw Project is comprised of two phases. The first phase of improvements provides downstream capacity up through completion of Woodbury’s Phase I AUAR development area. The second phase of improvements will provide downstream capacity through storage as well as a principal and emergency outlet for full development through 2020.
Design work is underway for phase II of the project—restoration/stabilization of the channel south of TH61. This work will be coordinated with 3M and ongoing restoration efforts led by Friends of the Mississippi River. Implementation of phase II is scheduled for 2015.
Clear Channel Pond
Background-Clear Channel Pond is situated in Cottage Grove. If the pond experiences flood conditions the overflow spills into St. Paul Park thereby presenting an inter-community flow issue. In order to protect the adjacent railroad tracks, modeling by Cottage Grove suggests the need to maintain the existing overland flow route from Cottage Grove into St. Paul Park during major events. Many parties are involved in the dialogue to find a solution. One proposed solution is to construct a lift station for Clear Channel Pond that would discharge to Hamlet Park Pond which is already experiencing water level issues (see section 184.108.40.206). A second, and preferred, solution is to expand stormwater storage in the area that would serve to relieve Clear Channel Pond, help protect infrastructure, and reduce flooding from inter-community flows. At this time, efforts will focus on the second solution, which is more cost-effective. To move forward with the Clear Channel Pond relief project in three phases. First, SWWD, Washington County and Cottage Grove will purchase the former Wheels of Travel property adjacent to Clear Channel Pond. Second, a study will be conducted to examine options to increase storage and design a storage facility. Finally, the stormwater storage facility will be constructed.
Construction-In October 2013, after easements for the lower portion of the project were acquired, Minnesota Native Landscapes began construction that will isolate the lower ponds from the ravine to allow for stabilization. SWWD will continue to work with landowners to acquire the remaining easements to begin construction on the upper portion of the ponds in 2014.
Grey Cloud Island Slough Restoration
Background-The Grey Cloud Slough is located east of the main channel of the Mississippi River, near the boundary between Grey Cloud Township and St. Paul Park. Although described as a “slough” this 2.8 mile long waterbody is a “cut-off” meander loop of the Mississippi River. The mouth of the meander begins at Mississippi River Mile (RM) 827.6 and ends at the confluence of a larger backwater portion of the River immediately north of Grey Cloud Island.
Ecological functions and services provided by the meander are diminished, in part, because of the loss of longitudinal connectivity with the Mississippi River. Water no longer flows through the meander due to blockage of the culverts under the roadway at the mouth of the meander. Restoration of the ecological functions and services historically provided by the Grey Cloud Slough as a meander of the Mississippi River is a priority for many local, state, and federal agencies.
SWWD is providing local leadership for this project by completing a feasibility study for restoring ecological functions and services. Working with its consultants and a Technical Advisory Committee made up of various local, state, and federal agency representatives, SWWD will identify a preferred solution to restoring connectivity with the Mississippi River. With a preferred solution identified, SWWD will work to develop partnerships with other agencies and secure funding to implement the project.
Background-SWWD secured a FY 2012 Clean Water Fund grant for installation of priority BMP’s throughout the Trout Brook watershed which were identified through the WCD’s Top50P! project.
Construction-Two projects have been approved by the SWWD Board. The Schuster project is complete. The Schoonover project is underway and held up due to wet weather. Staff is continuing attempts to develop other high value projects. However, if we cannot get landowner buy in for those projects before the end of 2014, SWWD will return approximately $25,000 of the grant to BWSR.
Background-SWWD has completed a retrofit scoping/feasibility study for the Afton Alps ski area. The study identifies several options for restoring habitat in Trout Brook and reducing sediment and phosphorus export to Trout Brook and Lake St. Croix. After reviewing the plan, MnDNR is engaged and excited to develop a partnership with SWWD and Afton Alps Ski Area and pursue a larger scale stream restoration project than SWWD would be able to accomplish on its own.
Construction- Once partners reach consensus on a reconstruction concept, MnDNR and SWWD will be positioned to seek grant funding throughout 2014/2015. As that design process continues we are tentatively planning to work with MnDNR and Conservation Corps to begin riparian invasive control in the park and install some in stream structures to begin controlling sediment bedload.
Colby Lake Water Re-Use
Background-SWWD, working in partnership with the City of Woodbury and Washington County, has secured a 2013 Clean Water Land and Legacy Grant to fund construction of water re-use systems at Eagle Valley and Prestwick Golf Courses. Work on the two systems is expected to begin in 2013. When the two systems are completed, the immediate watershed load reduction necessary to restore Colby Lake will be met. Additional work will still be required upstream (Wilmes Lake) and in-lake.
Construction-Construction is well underway. Work is largely complete at Eagle Valley golf course while some work remains at Prestwick. The County has expended the first (50%) grant payment and SWWD has issued the second (40%) payment to the County.
2014 Clean Water Cost Share Program
Opportunities for regional water quality improvement projects are limited and difficult to coordinate. Opportunities for smaller projects, however, exist on every residential, municipal, and commercial property. The South Washington Watershed District (SWWD) Clean Water Cost Share Program offers financial assistance to encourage and enable citizens, municipalities, and businesses to use innovative practices to protect and improve lakes and streams within the district. This program promotes water quality improvement by focusing on the reduction of phosphorus in stormwater runoff. Each pound of phosphorus, a nutrient critical to algae growth, removed from stormwater runoff can prevent up to 500 pounds of algae in our lakes, streams, and rivers.
SWWD Water Quality Work
SWWD continues to work on a watershed-wide water quality management program. Work is progressing on a subwatershed basis and resulting load allocations are subwatershed specific. The program involves five phases:
-Monitoring and watershed and in-lake water quality modeling
-Load allocation based on SWWD water quality goals, MN water quality standards, and future Mississippi River or St. Croix River TMDL requirements
-Subwatershed retrofit analysis, in cooperation with local municipalities, prioritizing BMPs to meet load allocations based on cost-effectiveness
-Implementation of projects identified in retrofit analysis using existing SWWD Cost Share, CCIP, and water quality implementation funds and existing municipal implementation funding
-Monitoring to confirm water quality improvements projected in retrofit analysis
The watershed-wide water quality management program draws from and coordinates current SWWD and WCD efforts and programs to achieve water quality goals set in the SWWD watershed management plan, fulfill TMDL requirements for impaired waters within the district, and meet load allocations from future Mississippi River and St. Croix River TMDLs. Currently SWWD has completed the Powers Lake allocation and is working with the WCD to complete the subwatershed retrofit analysis. In 2011, SWWD will work on an allocation and retrofit analysis for the Central Ravine subwatershed and increase monitoring activity around Colby Lake to collect data necessary to complete an allocation on 2012. Below is a phasing map.
CD P85 Restoration
In preparation of development in the southern portions of Woodbury and northern portions of Cottage Grove (East Ravine) the SWWD began restoration of the CD P85/86 greenway corridor. In 2013, SWWD contracted Great River Greening to complete prairie restoration and maintenance at its Central Draw regional infiltration basins. The contract includes proposed work through June 2017 and includes prairie/savanna establishment and maintenance, development and coordination of volunteer events, development and oversight of a simulated grazing (i.e. haying) program, and development of research opportunities with the University of Minnesota. This work will partially be funded through LCCMR funds through Great River Greening. Once restored, the basins will provide regional water quality treatment and flood control while also serving as public open space and providing key connections in regional greenway and trail corridors.
Powers Lake Protection
Historically Powers Lake was a land locked basin that exhibited fluctuations in water levels over time. Through development of the Woodbury East Alternative Urban Areawide Review the drainage area of Powers Lake was increased. During development of the watershed the SWWD worked with the City of Woodbury to incorporate infiltration practices into the construction of stormwater management facilities throughout the Powers Lake watershed.
With stormwater controls in place through development the lake water quality continues to trend downward. The SWWD in cooperation with the City of Woodbury and the Washington Conservation District have begun to implement retrofit projects to increase the protection of the lake. Additional actions will be necessary to address high internal loading
Chain of Lakes Restoration
The paradigm of stormwater management in the United States has shifted focus from primarily flood control to improving water quality. This shift is the result of implementation of water quality requirements of the Clean Water Act (CWA) of 1972. The CWA prohibits the discharge of pollutants from point sources to waters of the United States. This was accomplished through the development of a permit system known as the National Pollutant Discharge Elimination System (NPDES). While this regulatory mechanism has largely addressed point discharges (i.e. pipes or man-made ditches) a large source of pollutants still exists in non-point sources. Non-point sources are those that are not collected in a point source rather run off the land in the form of nutrients, chemicals and bacteria.
The SWWD has embarked on a program to systematically inventory, assess, analyze and identify sources and corrective actions that will minimize the delivery of non-point source pollution to the rivers, streams lakes and wetlands of the watershed. The goal of the program is to achieve the recommended pollutant reduction that results in water quality improvement through the most cost efficient means.
Beginning in 2009 the SWWD is analyzing each sub-watershed area of the watershed and identifying “hot spots” of pollution. Concurrent with this analysis is an inventory of potential projects to reduce the delivery of pollution to a particular water body. The result is a list of projects, timetable for implementation and an estimate cost of the project to achieve a quantifiable reduction goal. The SWWD then works with residents, commercial properties, institutions, developers, Cities and the County to implement the projects through various mechanisms. To date, assessments have been completed for the Powers and Colby Lake sub-watersheds and implementation is underway. Assessments for Armstrong, Markgrafs, and Wilmes Lakes will be completed in 2012/2013. Remaining SWWD sub-watersheds will follow.
The St. Croix and Trout Brook subwatersheds were transferred to SWWD in 2010 and make up roughly 10% (7130 acres) and 8% (5530 acres) of the District. These basins drain directly to Lake St. Croix of the Lower St. Croix River which is designated as an Outstanding Resource Value Water (ORVW) and currently listed as impaired for excess nutrients.
The St. Croix River is an important resource both locally and regionally. Currently listed as impaired, a TMDL study is underway to address excess nutrient loading. The District will cooperate with the ongoing study and work with municipalities and Washington County to implement water quality improvement projects in an effort to achieve load reductions identified in the TMDL study.
Several erosion areas have been identified along both Trout Brook and the St. Croix River and it is likely that other eroded or erosion prone areas exist. These areas contribute to ongoing degradation of the St. Croix River and will be addressed as part of implementing load reductions expected to be required as part of the St. Croix River TMDL.
Currently, SWWD is participating in two coordinated efforts to address identified issues. First, SWWD is working with the Washington Conservation District (WCD) to identify and address the biggest sources of phosphorus in the watershed through WCD’s Top50P! project. Second, SWWD has secured a State Clean Water Assistance grant to address additional sites identified as part of the Top50P! assessment.
Watershed Monitoring Reports-Washington Conservation District (WCD)
These documents contain a summary of methods and results for various surface water monitoring efforts by the Washington Conservation District (WCD). Generally, data is presented with respect to 8 lake levels, groundwater levels at 7 stations; stream flow discharge rate, volume and quality, runoff discharge rate and volume, precipitation; and, lake water quality for Armstrong and Powers Lakes. Discussion and interpretation of the results was outside the scope of the documents
Frost/Snow Monitoring Report
The South Washington Watershed District has the Washington Conservation District (WCD) conducted frost/snow monitoring at these existing frost monitoring sites (Cottage Grove Ravine Park, CDP-85 locations, CDP-86 locations, and MS-1. This report summarizes the methods and results for monitoring conducted from December 9, 2005 to March 22, 2006.