Minnehaha Creek Watershed District 30 Years of Water Resources Management 1967 - 1997 Page 2

The year 1997 marks the 30th year of the Minnehaha Creek Water- shed District (MCWD). The MCWD is one of the largest watershed districts in the Twin Cities metropolitan area. The District covers an area of 181 square miles in Hennepin and Carver Counties. The watershed extends 29 miles from St. Bonifacius in western Henne- pin County to the Mississippi River in Minneapolis and includes all or portions of 30 communities. There are 109 lakes, eight major creeks, and thousands of wetlands. Important water resources lo- cated within the district include Lake Minnetonka, Minnehaha Creek, the Minneapolis Chain of Lakes, and Minnehaha Falls. The District is managed by a seven-member Board of Managers appointed by Hennepin County (6) and Carver County (1).

The District has been a leader in planning and implementing water management projects and policies to improve water quality and re- duce flooding. Major studies, projects, activities, and accomplish- ments over the past 30-years are highlighted in this booklet.

Establishment of the MCWD (1967) The Minnehaha Creek Watershed District was established in 1967 under the authority of the state legislature at the request of the Hen- nepin County Board of Commissioners. The petition filed by the County in 1966 sought establishment of the district to conserve the waters and natural resources of the watershed. Their goals included improving lakes, marshes and channels for water storage, drainage, recreation and other public purposes. The County also wanted to develop projects to reduce flooding, to keep silt out of streams, and to control erosion of land. Other goals were reclaiming wetlands, controlling stormwater, and preserving water quality within the District’s lakes and streams. Minnehaha Creek Watershed District

Holy Name Lake Katrina Lake Wolsfied Lake Mooney Lake PLYMOUTH MAPLE PLAIN 101 INDEPENDENCE 12 LONG LAKE Long Lake 110

Gleason GOLDEN VALLEY 94 Lake WAYZATA 15 394 ORONO Brownie Lake Lake of Gray's Bay 94 Dam the Isles Twin Lakes 55 Dutch MINNETONKA 169 ST. LOUIS Cedar Lake WOODLAND Lake PARK Lower Lake Mississippi River Minnetonka DEEPHAVEN Bass 15 SPRING PARK 7 Lake Langdon MOUND MCWD OFFICE Lake Calhoun 35W Lake 100 HOPKINS MINNEAPOLIS Minnehaha Creek 110 Lake Hiawatha TONKA BAY GREENWOOD Upper Lake Lake Harriet WATERTOWN Minnetonka 7 Lake Nokomis 494 ST. BONIFACIUS EXCELSIOR 101 Minnehaha Falls MINNETRISTA 19 EDINA Mud 44 Christmas 7 Lake Lake Virginia Lake Stone Lake 62 Parley Zumbra HENNEPIN CO. RICHFIELD Lake VICTORIA Lake CARVER CO. Lake 100 Shultz Minnewashta 35W Lake Lunsten Lake Auburn Lake Steiger CHANHASSEN Lake 5 5 494 LAKETOWN Wasserman Lake Pierson Lake

Marsh Lake

Minnehaha Creek Watershed District 30 Years of Water Resources Management Page 3

Regulatory Program (1967-Present) A regulatory program was initiated in 1967 to mitigate the impacts of new land development and other projects on water resources within the District. Through the regulatory program, the District has re- viewed and approved stormwater management plans and shaped projects in floodplains and wetlands. The regulatory program has also covered dredging, stream and lake crossings, and shoreline im- provement projects. To date, the District has issued over 2,000 per- mits. 1996 Permit Applications (2) Rule B: Stormwater Management Plans Rule C: Floodplain Alteration Rule D: Wetland Protection Rule E: Dredging Rule F: Shoreline and Streambank Improvements Rule G: Stream & Lake Crossings Rule I: Variances Rule K: Dredging Contractor License Rule K: Performance Bond or Letter of Credit Rule L: Wetland Conservation Act Adoption Rule L: Shoreline Improvement Contractor's License Rule M: Shoreline Improvement Contractor's License TOTALS PERCENTAGE OF TOTAL

Chanhassen 2 1 1 1 5 1.2% Deephaven 2 1 8 1 1 2 15 3.5% Edina 3 2 2 2 1 10 2.3% Excelsior 4 3 1 21 1 3 3 2 38 8.9% Greenwood 0 1 7 1 1 4 14 3.3% Hopkins 1 1 0.2% Independence 1 1 1 3 0.7% Laketown Township 1 1 2 0.5% Long Lake 5 1 5 2 1 2 16 3.7% Medina 1 1 1 1 4 0.9% Minneapolis 8 2 1 3 14 3.3% Minnetonka 19 3 3 2 27 6.3% Minnetonka Beach 0 3 1 4 0.9% Minnetrista 3 1 1 2 10 1 2 4 24 5.6% Mound 3 5 1 1 23 1 1 5 4 44 10.3% Orono 7 2 7 20 1 7 1 6 4 55 12.9% Plymouth 7 1 8 1.9% Shorewood 9 3 7 29 1 1 3 2 15 70 16.4% Spring Park 2 4 10 3 19 4.4% St. Bonifacious 1 1 1 3 0.7% St. Louis Park 5 1 6 1.4% Tonka Bay 2 2 1 13 2 2 22 5.1% Victoria 2 1 2 1 4 10 2.3% Wayzata 5 1 2 4 12 2.8% Woodland 0 1 1 2 0.5%

TOTALS(2): 93 30 33 6 168 11 3 2 22 3 25 32 428 PERCENTAGE 21.7% 7.0% 7.7% 1.4% 39.3% 2.6% 0.7% 0.5% 5.1% 0.7% 5.8% 7.5% 100.0%

(1) A total of 279 permits were applied for in 1996. (2) Multiple rules apply to some permit applications Note: Rule K and Rule L definitions were altered during the year 1996.

Minnehaha Creek Watershed District 30 Years of Water Resources Management Page 4

Annual Hydrologic Monitoring (1968-Present) Wayzata Bay Since 1968, the District has been collecting hydrologic data Average Annual Summer Surface Values throughout the watershed on an annual basis to define watershed 0.12 hydrologic problems, provide information used in making watershed 0.10 management decisions, and evaluate how well completed projects can function. The District has built one of the best long-term water 0.08 quality and quantity data bases in the metropolitan area. The 0.06 monitoring program has been modified and expanded throughout the 0.04 years to more fully represent the quality and quantity aspects of the 0.02 District’s water resources. Since implementation in 1968, hydrologic Total Phosphorus (mg/l) 0.00 data collected includes precipitation, lake levels, stream flows, lake 1969 1973 1977 1981 1985 1989 1993 and stream water quality, and groundwater levels and water quality. Water quality trend graph showing Monitoring results have been summarized in annual hydrologic data phosphorus concentrations in Wayzata reports published by the District. Bay on Lake Minnetonka. Overall Plan for Water Management (1969) In 1969, the District’s first water management plan was prepared. The plan identified surface and groundwater problems and possible corrective actions that could be taken alleviate the problems. The plan focused on three problem areas, namely water pollution, flood control, and low water levels during dry periods. Recommendations included removing all sewage treatment plant effluent from Lake Minnetonka to improve water quality and reducing flooding along Minnehaha Creek by constructing an outlet control structure to regulate discharge from Lake Minnetonka . Elimination of Municipal Wastewater Discharges to Lake Minnetonka (1971-1986) The District worked closely with local and regional governments to eliminate wastewater discharges to Lake Minnetonka from seven municipal sewage treatment plants. Municipal wastewater discharges Water quality monitoring plays a significant role were phased out over a 15-year period from 1971-1986 resulting a in determining needed improvements as well as significant reduction in phosphorus loads to multiple streams, evaluating the performance of completed projects. wetlands, and Lake Minnetonka. A dramatic improvement in lake water quality was documented by the District's annual hydrologic monitoring.

Minnehaha Creek Watershed District 30 Years of Water Resources Management Page 5

Summary of Past Municipal Wastewater Discharges to the Lake Minnetonka Watershed

Effluent Phosphorus Start Phase-Out Flow(1) Load(2) Municipality Receiving Water Date Date (mgd) (lb/yr)

Excelsior Gideons Bay 1927 1972 0.53 8,640

Long Lake Tanager Lake/Browns Bay 1963 1980 0.31 3,160

Maple Plain Painter Creek/Jennings Bay 1951 1986 0.24 4,130

Mound Langdon Lake/Cooks Bay 1963 1974 1.37 17,880

Orono French Lake/Crystal Bay 1963 1980 0.48 2,010

Victoria Auburn Lake/Halsteds Bay 1958 1973 0.22 1,160

Wayzata Peavey Pond/Browns Bay 1939 1971 0.53 13,800

Total2 50,780 Notes: (1) Maple Plain flow in 1982. Victoria flow based on one-week field survey by MPCA in 1969. Other flows, average for two years prior to phase-out. (mgd = million gallons per day) (2) Effluent total phosphorus load in 1969-1970. (lb/yr = pounds per year)

Wayzata Wetland Study for USEPA (1975) The District pioneered a federally funded wetland study in 1975 to evaluate how well wetlands treat urban stormwater runoff and re- move nutrients such as phosphorus. A 7-acre wetland located in Wayzata with a 70-acre drainage area was selected for the study. The study defined the role natural wetlands play in the hydrologic cycle and demonstrated that wetlands are effective as a non-struc- tural treatment method in removing nutrients and contaminants con- tained in urban stormwater runoff. The wetland used in the study retained 77 percent of all phosphorus and 94 percent of the total sus- pended solids entering the site during the evaluation period. Results from the District’s wetland research were published by the U.S. EPA and became a national guidance document used in the management of urban stormwater runoff.

Minnehaha Creek Watershed District 30 Years of Water Resources Management Page 6

Construction of Gray’s Bay Dam and Outlet (1979-1980) One of the original goals of the District was to control flood damage along Minnehaha Creek. Most of the damage was occurring along the lower reach of the creek in commercial, residential, and park areas constructed within the floodplain. At the request of five communities located along the creek, the District improved the existing dam at Gray’s Bay and constructed an outlet control structure in 1979-1980. The purpose of the improvement was to manage water levels in Lake Minnetonka and reduce downstream flooding along Minnehaha Creek. The outlet control structure was constructed with three adjustable stainless steel gates to release water at a controlled rate from about May to November and is equipped with a fish screen. The recreational facilities at the Gray’s Bay Dam site were also Construction of an outlet control structure upgraded by the District as part of this project including construction and improvements to Gray's Bay Dam of a paved parking lot, picnic facilities, toilets, bike racks, drinking helped to minimize flooding to communities fountain, and canoe landing. downstream of Lake Minnetonka. Minnehaha Creek Channel Improvements at I-494 in Minnetonka (1979-1980) A section of the upper reach of Minnehaha Creek was dredged by the District in the vicinity of the I-494/Minnetonka Blvd. interchange in 1979-1980 to increase the flow capacity of the creek. This work, coordinated with the City of Minnetonka and Mn/DOT, involved lowering the creekbed by up to 2 feet by removing accumulated sediment along a 4,600-foot reach of the creek and stabilizing creekbanks.

Minnehaha Creek channel dredging at I-494.

Minnehaha Creek Watershed District 30 Years of Water Resources Management Page 7

Minnehaha Creek Recreational Improvements (1979-1980) Recreational and channel improvements along Minnehaha Creek between its headwaters and France Avenue within the cities of Minnetonka, Hopkins, St. Louis Park, and Edina were completed by the District in 1980. This work included the construction of canoe landings and portages, parking areas, picnic and sanitary facilities, bike racks, wildlife ponds, raising of pedestrian bridges, installation of culverts, and minor channel maintenance and repair.

Minnehaha Creek Channel Improvements at West 44th Street in Edina (1981) In 1981, the District dredged out a 1,300-foot section of Minnehaha Creek in the vicinity of West 44th Street in Edina. The project, funded jointly with the City of Edina, improved the flow capacity of the channel resulting in lower upstream flood elevations.

Hydraulic/Flood Study of Minnehaha Creek in Minneapolis (1982-1983) In 1980, the District completed In 1982-1983 the District and City of Minneapolis jointly undertook recreational and channel improvements a hydraulic study of flooding along a portion of Minnehaha Creek that included the installation of canoe west of I-35W. The study made use of a HEC-2 stream hydraulic landings along portions of Minnehaha model application previously developed by the U.S. Geological Creek (Utley Park canoe landing shown Survey for a flood insurance investigation. Flood impacts were above). evaluated for six existing bridges and culverts. Impacts were found to be large at three of these locations. Beneficial hydraulic effects were investigated for three possible designs proposed by the City for the Logan Avenue bridge, a larger culvert at Penn Avenue, and removal of an abandoned bridge. Reductions of up to 2 feet in 50-year flood stage were found to result from these modifications and several homes were afforded more flood protection. The study recommended a new single-span Logan Avenue bridge and a wider, higher Penn Avenue culvert. Removal of the abandoned bridge near Pleasant Avenue was not justifiable on the basis of flood impacts alone because the location is far downstream from flood-sensitive residential areas.

TR-20 Runoff Model (1983) Surface water runoff impacts many District activities including floodplain management, stream flow forecasting, lake level regulation, drainage system design, water quality control, recreation, and fish and wildlife management. The District has modeled the entire watershed using the Soil Conservation Service TR-20 computer model under the existing and unmanaged future conditions for the 1, 10, and 100-year storm events. These values assist in establishing a framework for effective water quantity management. The model was first developed for the watershed in 1983 and later updated in 1997. The extensive effort involved the modeling of 153 individual subwatersheds. Modeling results are included in the District’s water resources management plan.

Minnehaha Creek Watershed District 30 Years of Water Resources Management Page 8

Minnehaha Creek Channel Improvements at T.H. 100 in Edina (1984) Under a cooperative project with the City of Edina and Mn/DOT, the District reconstructed a 300-foot section of Minnehaha Creek upstream and downstream of the Highway 100 bridge crossing to restore the creek channel profile to that of the original bridge design plans from 1970. The project was planned and funded jointly with the City and Mn/DOT, and designed and built by the District. The channel improvements resulted in the lowering of the surface water profile upstream of Highway 100 where low-lying properties are located within the 100-year floodplain.

Painter Creek Subwatershed Improvement Project (1984-1985) Painter Creek, a major tributary to Lake Minnetonka, was known to carry large amounts of sediment and phosphorus from its 8,500 acre drainage area. During the winter of 1984-1985, the District constructed four detention basins, two sedimentation basins, and one fish barrier within the Painter Creek Subwatershed. A one mile stretch of Painter Creek was also cleaned and repaired. The project reduced nonpoint source pollution from the Painter Creek subwatershed improving water quality in Lake Minnetonka and also provided an additional 900 acre-feet of flood storage under 100-year storm Painter Marsh. conditions.

Draft Water Resources Management Plan (1987) In 1982, Minnesota Legislature adopted the Metropolitan Surface Water Management Act (Chapter 509) mandating that all watersheds within the Twin Cities Metropolitan Area be governed by a watershed management organization and that watershed management plans be prepared. In accordance with the law, the District completed a draft water resources management plan in 1987 focusing on preservation and use of natural water storage and retention systems and designed to achieve the following five basic primary objectives:

· To reduce, to the greatest possible extent, the public expenditures necessary to control excessive volumes and rates of runoff. · To improve water quality. · To prevent flooding and erosion from surface flows. · To promote groundwater recharge. · To protect and enhance fish and wildlife habitat and water recreation facilities.

The plan was submitted to various agencies for review and comment and to the Board of Soil and Water Resources for approval.

Minnehaha Creek Watershed District 30 Years of Water Resources Management Page 9

Long Lake Diagnostic/Feasibility Study (1989-1994) In 1989, the District undertook a study of Long Lake to assess its water quality (diagnostic study) and to develop a plan for water quality improvement (feasibility study). Field work included lake, stream, and storm sewer monitoring, and was conducted during the period October 1989- September 1990 (water year 1990). Long Lake was found to be in an advanced stage of eutrophication. For the 1990 summer season, Secchi transparency averaged only 3 feet, chlorophyll-a levels indicated frequent nuisance algae blooms, and total phosphorus concentrations averaged two to four times higher than is typical for unimpacted lakes in the ecoregion. The quantity of phosphorus released into the water from bottom sediments (internal load) was found to be comparable to the inputs from streams and other sources (external load); each of these loads was a little over 3,000 pounds per year. To reduce the external load, a wet detention pond was recommended along the lake’s main tributary near County Road 6 , along with upgrading of stormwater ponds in a park in the City of Long Lake. The recommendation for reducing internal load was originally enhanced aeration, but a change was later made to alum treatment. The diagnostic/feasibility study report was published in 1993, with a further report on feasibility completed in 1994.

Approval of Water Resources Management Plan (1993) After a lengthy review process, the District’s water resources management plan was approved in 1993 by the Board of Water and Soil Resources which paved the way for several District water quality improvement projects.

Gleason Creek Improvement and Flood Control Project (1993-1995) In 1994, the District completed the construction of Phase One of the Gleason Creek Improvement Project, a cooperative project with the City of Wayzata. The project involved construction of a new outlet control structure on Gleason Lake, expansion of one and creation of a second stormwater pond and extensive storm sewer improvements. The project provides significantly improved flood control along Gleason Creek and improved water quality in Lake Minnetonka. In 1995, the District completed Phase Two of the Project which focused on improving the water quality of Gleason Lake by reconstruction and enhancement of a wetland at the inlet to the lake.

Construction of this outlet structure on Gleason Lake provided improved flood control along Gleason Creek.

Minnehaha Creek Watershed District 30 Years of Water Resources Management Page 10

Twin Lakes Subwatershed Improvement Project (1995-1996) In a cooperative effort to restore water quality in the Minneapolis Chain of Lakes, the District entered into a partnership (Clean Water Partnership) with the cities of Minneapolis and St. Louis Park, the Minneapolis Park and Recreation Board, and Hennepin County. A feasibility study was performed by the District in 1994 to provide technical recommendations for watershed improvements to the Twin Lakes Subwatershed, a 1,500 acre drainage area consisting of well- developed residential and commercial areas in St. Louis Park that contribute over 50% of the flow and over 60% of the phosphorus Twin Lakes dredging. load to Cedar Lake. The goal of the project was to optimize water quality improvement of stormwater runoff entering Twin Lakes and Cedar Lake by removing phosphorus, sediment, and other pollutants naturally through physical and biological processes. Designed, built, and funded by the District, the initial phase of structural water quality improvements were completed in 1996. These improvements consisted of constructing a wet detention basin upstream of Twin Lakes and a wet detention basin/wetland system near Cedar Lake, dredging Twin Lakes, and diverting stormwater runoff.

Long Lake Improvement Project (1995-1996) The Cedar Meadows wet detention basin/ The first phase of watershed improvements, completed in 1996 as wetland system treats inflows to nearby part of the Long Lake Improvement Project, involved the construction Cedar Lake. of a large two-cell wet detention basin in Medina, on a major tributary to Long Lake, and the expansion and enhancement of two existing sedimentation basins in the City of Long Lake. A subsequent project phase including the construction of an additional wet detention basin in Orono is planned to be completed in 1998.

View prior to construction of the wet detention basin in Medina.

After construction of the wet detention basin.

Minnehaha Creek Watershed District 30 Years of Water Resources Management Page 11

Long Lake Alum Treatment (1996) Long Lake was treated with aluminum sulfate (alum) by the District in the Spring of 1996 to remove phosphorus from the water column and to retard the release of phosphorus from lake bottom sediments. By late summer of that year, water clarity in Long Lake had increased from 2 feet to 15 feet. Alum has proven to provide a safe and effective solution to control of the amount of algae present in lakes.

MDNR Outstanding Watershed District of the Year (1996) Long Lake alum application. The MCWD was honored as watershed district of the year at the 1996 Minnesota Association of Watershed Districts (MAWD) annual meeting. The Outstanding Watershed District Award was presented to the District by the Minnesota Department of Natural Resources (DNR). In presenting the award, the DNR cited four to the District’s major achievements:

· Working with the DNR on a streamlined process for obtaining general permits. · Enhancing MCWD rules to provide for better adherence to the land alteration requirements. · Adopting a wetland buffer requirement to further protect wetland resources. · Developing Minnesota’s first watershed Internet site and helping develop on Internet presence for the remaining 41 state watershed districts on the MAWD Home Page.

The District was also recognized for using regulation, education, and water resource projects in a comprehensive way to protect and improve the water resources in the most heavily populated district in the state. Thirty years of proactive management of the Minnehaha Creek Watershed has Painter Creek Subwatershed Maintenance Project provided the community with an exceptional recreational and aesthetic (1996-1997) environment. Designed to restore the flood storage capacity created by the 1985 project and enhance the water quality treatment capability, accumulated sediment was removed and the two existing basins enlarged and depend at the South Katrina and Painter Marsh sites by the District in 1997. The existing outlets were also modified to prevent blockages.

Minnehaha Creek Watershed District 30 Years of Water Resources Management Page 12

Minnesota Landscape Arboretum Wetland Restoration (1996-1997) The “Spring Peeper Meadow Restoration” project at the University

5 of Minnesota Landscape Arboretum in Chanhassen was completed in 1997. The District provided $250,000 toward this wetland Wetland Watershed 41 restoration project which will be showcased for public learning, Boundary (Approximately 50 Acres) experiences, demonstrations, and on-going research on wetland regeneration. The site’s hydrology was restored by breaking the network of drain tiles below the soil surface. Native plant species

WETLAND were planted in the wetland basin and a boardwalk and interpretive BASIN trail constructed within the basin to provide access to the 20-acre wetland for close viewing and plant identification.

N Gray’s Bay Outlet Maintenance and Repair (1997) The overflow spillway at the Gray’s Bay outlet had fallen into disrepair over the years through erosion and settlement. Maintenance and repair of the structure was performed by the District in 1997 to ensure proper 82nd STREET and safe implementation of the existing operation plan. This work consisted of installing timber piles to stabilize the steel sheet pile weir and constructing a new weir cap; placing riprap, boulders, and Contributing to the Minnesota Landscape cobbles along the lake side of the weir; filling and grading earth Arboretum is one method the District uses material for erosion protection and to confine lake overflow to the to help promote watershed education. weir area; extending and adding fences for safety; and removing large downed cottonwood trees.

Maintenance and repairs to the Gray's Bay overflow spillway were conducted in early 1997. View of overflow spillway after completion of repairs.

Minnehaha Creek Watershed District 30 Years of Water Resources Management Page 13

Approval of 2nd Generation Water Resources Management Plan (1997) The District’s 2nd Generation Water Resources Management Plan was approved by the Board of Water and Soil Resources in 1997. The plan identifies a series of capital improvement projects throughout the District, as well as specific strategies to reduce the continuing degradation of surface water in the watershed. The plan also reflects the District’s goals and policies for water resources management and protection, including the District’s increased emphasis on education and public participation.

Minnehaha Creek.

Please visit our Web Site at www.minnehahacreek.org

Minnehaha Creek Watershed District 30 Years of Water Resources Management Page 2

The year 1997 marks the 30th year of the Minnehaha Creek Water- shed District (MCWD). The MCWD is one of the largest watershed districts in the Twin Cities metropolitan area. The District covers an area of 181 square miles in Hennepin and Carver Counties. The watershed extends 29 miles from St. Bonifacius in western Henne- pin County to the Mississippi River in Minneapolis and includes all or portions of 30 communities. There are 109 lakes, eight major creeks, and thousands of wetlands. Important water resources lo- cated within the district include Lake Minnetonka, Minnehaha Creek, the Minneapolis Chain of Lakes, and Minnehaha Falls. The District is managed by a seven-member Board of Managers appointed by Hennepin County (6) and Carver County (1).

The District has been a leader in planning and implementing water management projects and policies to improve water quality and re- duce flooding. Major studies, projects, activities, and accomplish- ments over the past 30-years are highlighted in this booklet.

Establishment of the MCWD (1967) The Minnehaha Creek Watershed District was established in 1967 under the authority of the state legislature at the request of the Hen- nepin County Board of Commissioners. The petition filed by the County in 1966 sought establishment of the district to conserve the waters and natural resources of the watershed. Their goals included improving lakes, marshes and channels for water storage, drainage, recreation and other public purposes. The County also wanted to develop projects to reduce flooding, to keep silt out of streams, and to control erosion of land. Other goals were reclaiming wetlands, controlling stormwater, and preserving water quality within the District’s lakes and streams. Minnehaha Creek Watershed District

Holy Name Lake Katrina Lake Wolsfied Lake Mooney Lake PLYMOUTH MAPLE PLAIN 101 INDEPENDENCE 12 LONG LAKE Long Lake 110

Gleason GOLDEN VALLEY 94 Lake WAYZATA 15 394 ORONO Brownie Lake Lake of Gray's Bay 94 Dam the Isles Twin Lakes 55 Dutch MINNETONKA 169 ST. LOUIS Cedar Lake WOODLAND Lake PARK Lower Lake Mississippi River Minnetonka DEEPHAVEN Bass 15 SPRING PARK 7 Lake Langdon MOUND MCWD OFFICE Lake Calhoun 35W Lake 100 HOPKINS MINNEAPOLIS Minnehaha Creek 110 Lake Hiawatha TONKA BAY GREENWOOD Upper Lake Lake Harriet WATERTOWN Minnetonka 7 Lake Nokomis 494 ST. BONIFACIUS EXCELSIOR 101 Minnehaha Falls MINNETRISTA 19 EDINA Mud 44 Christmas 7 Lake Lake Virginia Lake Stone Lake 62 Parley Zumbra HENNEPIN CO. RICHFIELD Lake VICTORIA Lake CARVER CO. Lake 100 Shultz Minnewashta 35W Lake Lunsten Lake Auburn Lake Steiger CHANHASSEN Lake 5 5 494 LAKETOWN Wasserman Lake Pierson Lake

Marsh Lake

Minnehaha Creek Watershed District 30 Years of Water Resources Management Page 3

Regulatory Program (1967-Present) A regulatory program was initiated in 1967 to mitigate the impacts of new land development and other projects on water resources within the District. Through the regulatory program, the District has re- viewed and approved stormwater management plans and shaped projects in floodplains and wetlands. The regulatory program has also covered dredging, stream and lake crossings, and shoreline im- provement projects. To date, the District has issued over 2,000 per- mits. 1996 Permit Applications (2) Rule B: Stormwater Management Plans Rule C: Floodplain Alteration Rule D: Wetland Protection Rule E: Dredging Rule F: Shoreline and Streambank Improvements Rule G: Stream & Lake Crossings Rule I: Variances Rule K: Dredging Contractor License Rule K: Performance Bond or Letter of Credit Rule L: Wetland Conservation Act Adoption Rule L: Shoreline Improvement Contractor's License Rule M: Shoreline Improvement Contractor's License TOTALS PERCENTAGE OF TOTAL

Chanhassen 2 1 1 1 5 1.2% Deephaven 2 1 8 1 1 2 15 3.5% Edina 3 2 2 2 1 10 2.3% Excelsior 4 3 1 21 1 3 3 2 38 8.9% Greenwood 0 1 7 1 1 4 14 3.3% Hopkins 1 1 0.2% Independence 1 1 1 3 0.7% Laketown Township 1 1 2 0.5% Long Lake 5 1 5 2 1 2 16 3.7% Medina 1 1 1 1 4 0.9% Minneapolis 8 2 1 3 14 3.3% Minnetonka 19 3 3 2 27 6.3% Minnetonka Beach 0 3 1 4 0.9% Minnetrista 3 1 1 2 10 1 2 4 24 5.6% Mound 3 5 1 1 23 1 1 5 4 44 10.3% Orono 7 2 7 20 1 7 1 6 4 55 12.9% Plymouth 7 1 8 1.9% Shorewood 9 3 7 29 1 1 3 2 15 70 16.4% Spring Park 2 4 10 3 19 4.4% St. Bonifacious 1 1 1 3 0.7% St. Louis Park 5 1 6 1.4% Tonka Bay 2 2 1 13 2 2 22 5.1% Victoria 2 1 2 1 4 10 2.3% Wayzata 5 1 2 4 12 2.8% Woodland 0 1 1 2 0.5%

TOTALS(2): 93 30 33 6 168 11 3 2 22 3 25 32 428 PERCENTAGE 21.7% 7.0% 7.7% 1.4% 39.3% 2.6% 0.7% 0.5% 5.1% 0.7% 5.8% 7.5% 100.0%

(1) A total of 279 permits were applied for in 1996. (2) Multiple rules apply to some permit applications Note: Rule K and Rule L definitions were altered during the year 1996.

Minnehaha Creek Watershed District 30 Years of Water Resources Management Page 4

Annual Hydrologic Monitoring (1968-Present) Wayzata Bay Since 1968, the District has been collecting hydrologic data Average Annual Summer Surface Values throughout the watershed on an annual basis to define watershed 0.12 hydrologic problems, provide information used in making watershed 0.10 management decisions, and evaluate how well completed projects can function. The District has built one of the best long-term water 0.08 quality and quantity data bases in the metropolitan area. The 0.06 monitoring program has been modified and expanded throughout the 0.04 years to more fully represent the quality and quantity aspects of the 0.02 District’s water resources. Since implementation in 1968, hydrologic Total Phosphorus (mg/l) 0.00 data collected includes precipitation, lake levels, stream flows, lake 1969 1973 1977 1981 1985 1989 1993 and stream water quality, and groundwater levels and water quality. Water quality trend graph showing Monitoring results have been summarized in annual hydrologic data phosphorus concentrations in Wayzata reports published by the District. Bay on Lake Minnetonka. Overall Plan for Water Management (1969) In 1969, the District’s first water management plan was prepared. The plan identified surface and groundwater problems and possible corrective actions that could be taken alleviate the problems. The plan focused on three problem areas, namely water pollution, flood control, and low water levels during dry periods. Recommendations included removing all sewage treatment plant effluent from Lake Minnetonka to improve water quality and reducing flooding along Minnehaha Creek by constructing an outlet control structure to regulate discharge from Lake Minnetonka . Elimination of Municipal Wastewater Discharges to Lake Minnetonka (1971-1986) The District worked closely with local and regional governments to eliminate wastewater discharges to Lake Minnetonka from seven municipal sewage treatment plants. Municipal wastewater discharges Water quality monitoring plays a significant role were phased out over a 15-year period from 1971-1986 resulting a in determining needed improvements as well as significant reduction in phosphorus loads to multiple streams, evaluating the performance of completed projects. wetlands, and Lake Minnetonka. A dramatic improvement in lake water quality was documented by the District's annual hydrologic monitoring.

Minnehaha Creek Watershed District 30 Years of Water Resources Management Page 5

Summary of Past Municipal Wastewater Discharges to the Lake Minnetonka Watershed

Effluent Phosphorus Start Phase-Out Flow(1) Load(2) Municipality Receiving Water Date Date (mgd) (lb/yr)

Excelsior Gideons Bay 1927 1972 0.53 8,640

Long Lake Tanager Lake/Browns Bay 1963 1980 0.31 3,160

Maple Plain Painter Creek/Jennings Bay 1951 1986 0.24 4,130

Mound Langdon Lake/Cooks Bay 1963 1974 1.37 17,880

Orono French Lake/Crystal Bay 1963 1980 0.48 2,010

Victoria Auburn Lake/Halsteds Bay 1958 1973 0.22 1,160

Wayzata Peavey Pond/Browns Bay 1939 1971 0.53 13,800

Total2 50,780 Notes: (1) Maple Plain flow in 1982. Victoria flow based on one-week field survey by MPCA in 1969. Other flows, average for two years prior to phase-out. (mgd = million gallons per day) (2) Effluent total phosphorus load in 1969-1970. (lb/yr = pounds per year)

Wayzata Wetland Study for USEPA (1975) The District pioneered a federally funded wetland study in 1975 to evaluate how well wetlands treat urban stormwater runoff and re- move nutrients such as phosphorus. A 7-acre wetland located in Wayzata with a 70-acre drainage area was selected for the study. The study defined the role natural wetlands play in the hydrologic cycle and demonstrated that wetlands are effective as a non-struc- tural treatment method in removing nutrients and contaminants con- tained in urban stormwater runoff. The wetland used in the study retained 77 percent of all phosphorus and 94 percent of the total sus- pended solids entering the site during the evaluation period. Results from the District’s wetland research were published by the U.S. EPA and became a national guidance document used in the management of urban stormwater runoff.

Minnehaha Creek Watershed District 30 Years of Water Resources Management Page 6

Construction of Gray’s Bay Dam and Outlet (1979-1980) One of the original goals of the District was to control flood damage along Minnehaha Creek. Most of the damage was occurring along the lower reach of the creek in commercial, residential, and park areas constructed within the floodplain. At the request of five communities located along the creek, the District improved the existing dam at Gray’s Bay and constructed an outlet control structure in 1979-1980. The purpose of the improvement was to manage water levels in Lake Minnetonka and reduce downstream flooding along Minnehaha Creek. The outlet control structure was constructed with three adjustable stainless steel gates to release water at a controlled rate from about May to November and is equipped with a fish screen. The recreational facilities at the Gray’s Bay Dam site were also Construction of an outlet control structure upgraded by the District as part of this project including construction and improvements to Gray's Bay Dam of a paved parking lot, picnic facilities, toilets, bike racks, drinking helped to minimize flooding to communities fountain, and canoe landing. downstream of Lake Minnetonka. Minnehaha Creek Channel Improvements at I-494 in Minnetonka (1979-1980) A section of the upper reach of Minnehaha Creek was dredged by the District in the vicinity of the I-494/Minnetonka Blvd. interchange in 1979-1980 to increase the flow capacity of the creek. This work, coordinated with the City of Minnetonka and Mn/DOT, involved lowering the creekbed by up to 2 feet by removing accumulated sediment along a 4,600-foot reach of the creek and stabilizing creekbanks.

Minnehaha Creek channel dredging at I-494.

Minnehaha Creek Watershed District 30 Years of Water Resources Management Page 7

Minnehaha Creek Recreational Improvements (1979-1980) Recreational and channel improvements along Minnehaha Creek between its headwaters and France Avenue within the cities of Minnetonka, Hopkins, St. Louis Park, and Edina were completed by the District in 1980. This work included the construction of canoe landings and portages, parking areas, picnic and sanitary facilities, bike racks, wildlife ponds, raising of pedestrian bridges, installation of culverts, and minor channel maintenance and repair.

Minnehaha Creek Channel Improvements at West 44th Street in Edina (1981) In 1981, the District dredged out a 1,300-foot section of Minnehaha Creek in the vicinity of West 44th Street in Edina. The project, funded jointly with the City of Edina, improved the flow capacity of the channel resulting in lower upstream flood elevations.

Hydraulic/Flood Study of Minnehaha Creek in Minneapolis (1982-1983) In 1980, the District completed In 1982-1983 the District and City of Minneapolis jointly undertook recreational and channel improvements a hydraulic study of flooding along a portion of Minnehaha Creek that included the installation of canoe west of I-35W. The study made use of a HEC-2 stream hydraulic landings along portions of Minnehaha model application previously developed by the U.S. Geological Creek (Utley Park canoe landing shown Survey for a flood insurance investigation. Flood impacts were above). evaluated for six existing bridges and culverts. Impacts were found to be large at three of these locations. Beneficial hydraulic effects were investigated for three possible designs proposed by the City for the Logan Avenue bridge, a larger culvert at Penn Avenue, and removal of an abandoned bridge. Reductions of up to 2 feet in 50-year flood stage were found to result from these modifications and several homes were afforded more flood protection. The study recommended a new single-span Logan Avenue bridge and a wider, higher Penn Avenue culvert. Removal of the abandoned bridge near Pleasant Avenue was not justifiable on the basis of flood impacts alone because the location is far downstream from flood-sensitive residential areas.

TR-20 Runoff Model (1983) Surface water runoff impacts many District activities including floodplain management, stream flow forecasting, lake level regulation, drainage system design, water quality control, recreation, and fish and wildlife management. The District has modeled the entire watershed using the Soil Conservation Service TR-20 computer model under the existing and unmanaged future conditions for the 1, 10, and 100-year storm events. These values assist in establishing a framework for effective water quantity management. The model was first developed for the watershed in 1983 and later updated in 1997. The extensive effort involved the modeling of 153 individual subwatersheds. Modeling results are included in the District’s water resources management plan.

Minnehaha Creek Watershed District 30 Years of Water Resources Management Page 8

Minnehaha Creek Channel Improvements at T.H. 100 in Edina (1984) Under a cooperative project with the City of Edina and Mn/DOT, the District reconstructed a 300-foot section of Minnehaha Creek upstream and downstream of the Highway 100 bridge crossing to restore the creek channel profile to that of the original bridge design plans from 1970. The project was planned and funded jointly with the City and Mn/DOT, and designed and built by the District. The channel improvements resulted in the lowering of the surface water profile upstream of Highway 100 where low-lying properties are located within the 100-year floodplain.

Painter Creek Subwatershed Improvement Project (1984-1985) Painter Creek, a major tributary to Lake Minnetonka, was known to carry large amounts of sediment and phosphorus from its 8,500 acre drainage area. During the winter of 1984-1985, the District constructed four detention basins, two sedimentation basins, and one fish barrier within the Painter Creek Subwatershed. A one mile stretch of Painter Creek was also cleaned and repaired. The project reduced nonpoint source pollution from the Painter Creek subwatershed improving water quality in Lake Minnetonka and also provided an additional 900 acre-feet of flood storage under 100-year storm Painter Marsh. conditions.

Draft Water Resources Management Plan (1987) In 1982, Minnesota Legislature adopted the Metropolitan Surface Water Management Act (Chapter 509) mandating that all watersheds within the Twin Cities Metropolitan Area be governed by a watershed management organization and that watershed management plans be prepared. In accordance with the law, the District completed a draft water resources management plan in 1987 focusing on preservation and use of natural water storage and retention systems and designed to achieve the following five basic primary objectives:

· To reduce, to the greatest possible extent, the public expenditures necessary to control excessive volumes and rates of runoff. · To improve water quality. · To prevent flooding and erosion from surface flows. · To promote groundwater recharge. · To protect and enhance fish and wildlife habitat and water recreation facilities.

The plan was submitted to various agencies for review and comment and to the Board of Soil and Water Resources for approval.

Minnehaha Creek Watershed District 30 Years of Water Resources Management Page 9

Long Lake Diagnostic/Feasibility Study (1989-1994) In 1989, the District undertook a study of Long Lake to assess its water quality (diagnostic study) and to develop a plan for water quality improvement (feasibility study). Field work included lake, stream, and storm sewer monitoring, and was conducted during the period October 1989- September 1990 (water year 1990). Long Lake was found to be in an advanced stage of eutrophication. For the 1990 summer season, Secchi transparency averaged only 3 feet, chlorophyll-a levels indicated frequent nuisance algae blooms, and total phosphorus concentrations averaged two to four times higher than is typical for unimpacted lakes in the ecoregion. The quantity of phosphorus released into the water from bottom sediments (internal load) was found to be comparable to the inputs from streams and other sources (external load); each of these loads was a little over 3,000 pounds per year. To reduce the external load, a wet detention pond was recommended along the lake’s main tributary near County Road 6 , along with upgrading of stormwater ponds in a park in the City of Long Lake. The recommendation for reducing internal load was originally enhanced aeration, but a change was later made to alum treatment. The diagnostic/feasibility study report was published in 1993, with a further report on feasibility completed in 1994.

Approval of Water Resources Management Plan (1993) After a lengthy review process, the District’s water resources management plan was approved in 1993 by the Board of Water and Soil Resources which paved the way for several District water quality improvement projects.

Gleason Creek Improvement and Flood Control Project (1993-1995) In 1994, the District completed the construction of Phase One of the Gleason Creek Improvement Project, a cooperative project with the City of Wayzata. The project involved construction of a new outlet control structure on Gleason Lake, expansion of one and creation of a second stormwater pond and extensive storm sewer improvements. The project provides significantly improved flood control along Gleason Creek and improved water quality in Lake Minnetonka. In 1995, the District completed Phase Two of the Project which focused on improving the water quality of Gleason Lake by reconstruction and enhancement of a wetland at the inlet to the lake.

Construction of this outlet structure on Gleason Lake provided improved flood control along Gleason Creek.

Minnehaha Creek Watershed District 30 Years of Water Resources Management Page 10

Twin Lakes Subwatershed Improvement Project (1995-1996) In a cooperative effort to restore water quality in the Minneapolis Chain of Lakes, the District entered into a partnership (Clean Water Partnership) with the cities of Minneapolis and St. Louis Park, the Minneapolis Park and Recreation Board, and Hennepin County. A feasibility study was performed by the District in 1994 to provide technical recommendations for watershed improvements to the Twin Lakes Subwatershed, a 1,500 acre drainage area consisting of well- developed residential and commercial areas in St. Louis Park that contribute over 50% of the flow and over 60% of the phosphorus Twin Lakes dredging. load to Cedar Lake. The goal of the project was to optimize water quality improvement of stormwater runoff entering Twin Lakes and Cedar Lake by removing phosphorus, sediment, and other pollutants naturally through physical and biological processes. Designed, built, and funded by the District, the initial phase of structural water quality improvements were completed in 1996. These improvements consisted of constructing a wet detention basin upstream of Twin Lakes and a wet detention basin/wetland system near Cedar Lake, dredging Twin Lakes, and diverting stormwater runoff.

Long Lake Improvement Project (1995-1996) The Cedar Meadows wet detention basin/ The first phase of watershed improvements, completed in 1996 as wetland system treats inflows to nearby part of the Long Lake Improvement Project, involved the construction Cedar Lake. of a large two-cell wet detention basin in Medina, on a major tributary to Long Lake, and the expansion and enhancement of two existing sedimentation basins in the City of Long Lake. A subsequent project phase including the construction of an additional wet detention basin in Orono is planned to be completed in 1998.

View prior to construction of the wet detention basin in Medina.

After construction of the wet detention basin.

Minnehaha Creek Watershed District 30 Years of Water Resources Management Page 11

Long Lake Alum Treatment (1996) Long Lake was treated with aluminum sulfate (alum) by the District in the Spring of 1996 to remove phosphorus from the water column and to retard the release of phosphorus from lake bottom sediments. By late summer of that year, water clarity in Long Lake had increased from 2 feet to 15 feet. Alum has proven to provide a safe and effective solution to control of the amount of algae present in lakes.

MDNR Outstanding Watershed District of the Year (1996) Long Lake alum application. The MCWD was honored as watershed district of the year at the 1996 Minnesota Association of Watershed Districts (MAWD) annual meeting. The Outstanding Watershed District Award was presented to the District by the Minnesota Department of Natural Resources (DNR). In presenting the award, the DNR cited four to the District’s major achievements:

· Working with the DNR on a streamlined process for obtaining general permits. · Enhancing MCWD rules to provide for better adherence to the land alteration requirements. · Adopting a wetland buffer requirement to further protect wetland resources. · Developing Minnesota’s first watershed Internet site and helping develop on Internet presence for the remaining 41 state watershed districts on the MAWD Home Page.

The District was also recognized for using regulation, education, and water resource projects in a comprehensive way to protect and improve the water resources in the most heavily populated district in the state. Thirty years of proactive management of the Minnehaha Creek Watershed has Painter Creek Subwatershed Maintenance Project provided the community with an exceptional recreational and aesthetic (1996-1997) environment. Designed to restore the flood storage capacity created by the 1985 project and enhance the water quality treatment capability, accumulated sediment was removed and the two existing basins enlarged and depend at the South Katrina and Painter Marsh sites by the District in 1997. The existing outlets were also modified to prevent blockages.

Minnehaha Creek Watershed District 30 Years of Water Resources Management Page 12

Minnesota Landscape Arboretum Wetland Restoration (1996-1997) The “Spring Peeper Meadow Restoration” project at the University

5 of Minnesota Landscape Arboretum in Chanhassen was completed in 1997. The District provided $250,000 toward this wetland Wetland Watershed 41 restoration project which will be showcased for public learning, Boundary (Approximately 50 Acres) experiences, demonstrations, and on-going research on wetland regeneration. The site’s hydrology was restored by breaking the network of drain tiles below the soil surface. Native plant species

WETLAND were planted in the wetland basin and a boardwalk and interpretive BASIN trail constructed within the basin to provide access to the 20-acre wetland for close viewing and plant identification.

N Gray’s Bay Outlet Maintenance and Repair (1997) The overflow spillway at the Gray’s Bay outlet had fallen into disrepair over the years through erosion and settlement. Maintenance and repair of the structure was performed by the District in 1997 to ensure proper 82nd STREET and safe implementation of the existing operation plan. This work consisted of installing timber piles to stabilize the steel sheet pile weir and constructing a new weir cap; placing riprap, boulders, and Contributing to the Minnesota Landscape cobbles along the lake side of the weir; filling and grading earth Arboretum is one method the District uses material for erosion protection and to confine lake overflow to the to help promote watershed education. weir area; extending and adding fences for safety; and removing large downed cottonwood trees.

Maintenance and repairs to the Gray's Bay overflow spillway were conducted in early 1997. View of overflow spillway after completion of repairs.

Minnehaha Creek Watershed District 30 Years of Water Resources Management Page 13

Approval of 2nd Generation Water Resources Management Plan (1997) The District’s 2nd Generation Water Resources Management Plan was approved by the Board of Water and Soil Resources in 1997. The plan identifies a series of capital improvement projects throughout the District, as well as specific strategies to reduce the continuing degradation of surface water in the watershed. The plan also reflects the District’s goals and policies for water resources management and protection, including the District’s increased emphasis on education and public participation.

Minnehaha Creek.

Please visit our Web Site at www.minnehahacreek.org

Minnehaha Creek Watershed District 30 Years of Water Resources Management Page 2

The year 1997 marks the 30th year of the Minnehaha Creek Water- shed District (MCWD). The MCWD is one of the largest watershed districts in the Twin Cities metropolitan area. The District covers an area of 181 square miles in Hennepin and Carver Counties. The watershed extends 29 miles from St. Bonifacius in western Henne- pin County to the Mississippi River in Minneapolis and includes all or portions of 30 communities. There are 109 lakes, eight major creeks, and thousands of wetlands. Important water resources lo- cated within the district include Lake Minnetonka, Minnehaha Creek, the Minneapolis Chain of Lakes, and Minnehaha Falls. The District is managed by a seven-member Board of Managers appointed by Hennepin County (6) and Carver County (1).

The District has been a leader in planning and implementing water management projects and policies to improve water quality and re- duce flooding. Major studies, projects, activities, and accomplish- ments over the past 30-years are highlighted in this booklet.

Establishment of the MCWD (1967) The Minnehaha Creek Watershed District was established in 1967 under the authority of the state legislature at the request of the Hen- nepin County Board of Commissioners. The petition filed by the County in 1966 sought establishment of the district to conserve the waters and natural resources of the watershed. Their goals included improving lakes, marshes and channels for water storage, drainage, recreation and other public purposes. The County also wanted to develop projects to reduce flooding, to keep silt out of streams, and to control erosion of land. Other goals were reclaiming wetlands, controlling stormwater, and preserving water quality within the District’s lakes and streams. Minnehaha Creek Watershed District

Holy Name Lake Katrina Lake Wolsfied Lake Mooney Lake PLYMOUTH MAPLE PLAIN 101 INDEPENDENCE 12 LONG LAKE Long Lake 110

Gleason GOLDEN VALLEY 94 Lake WAYZATA 15 394 ORONO Brownie Lake Lake of Gray's Bay 94 Dam the Isles Twin Lakes 55 Dutch MINNETONKA 169 ST. LOUIS Cedar Lake WOODLAND Lake PARK Lower Lake Mississippi River Minnetonka DEEPHAVEN Bass 15 SPRING PARK 7 Lake Langdon MOUND MCWD OFFICE Lake Calhoun 35W Lake 100 HOPKINS MINNEAPOLIS Minnehaha Creek 110 Lake Hiawatha TONKA BAY GREENWOOD Upper Lake Lake Harriet WATERTOWN Minnetonka 7 Lake Nokomis 494 ST. BONIFACIUS EXCELSIOR 101 Minnehaha Falls MINNETRISTA 19 EDINA Mud 44 Christmas 7 Lake Lake Virginia Lake Stone Lake 62 Parley Zumbra HENNEPIN CO. RICHFIELD Lake VICTORIA Lake CARVER CO. Lake 100 Shultz Minnewashta 35W Lake Lunsten Lake Auburn Lake Steiger CHANHASSEN Lake 5 5 494 LAKETOWN Wasserman Lake Pierson Lake

Marsh Lake

Minnehaha Creek Watershed District 30 Years of Water Resources Management Page 3

Regulatory Program (1967-Present) A regulatory program was initiated in 1967 to mitigate the impacts of new land development and other projects on water resources within the District. Through the regulatory program, the District has re- viewed and approved stormwater management plans and shaped projects in floodplains and wetlands. The regulatory program has also covered dredging, stream and lake crossings, and shoreline im- provement projects. To date, the District has issued over 2,000 per- mits. 1996 Permit Applications (2) Rule B: Stormwater Management Plans Rule C: Floodplain Alteration Rule D: Wetland Protection Rule E: Dredging Rule F: Shoreline and Streambank Improvements Rule G: Stream & Lake Crossings Rule I: Variances Rule K: Dredging Contractor License Rule K: Performance Bond or Letter of Credit Rule L: Wetland Conservation Act Adoption Rule L: Shoreline Improvement Contractor's License Rule M: Shoreline Improvement Contractor's License TOTALS PERCENTAGE OF TOTAL

Chanhassen 2 1 1 1 5 1.2% Deephaven 2 1 8 1 1 2 15 3.5% Edina 3 2 2 2 1 10 2.3% Excelsior 4 3 1 21 1 3 3 2 38 8.9% Greenwood 0 1 7 1 1 4 14 3.3% Hopkins 1 1 0.2% Independence 1 1 1 3 0.7% Laketown Township 1 1 2 0.5% Long Lake 5 1 5 2 1 2 16 3.7% Medina 1 1 1 1 4 0.9% Minneapolis 8 2 1 3 14 3.3% Minnetonka 19 3 3 2 27 6.3% Minnetonka Beach 0 3 1 4 0.9% Minnetrista 3 1 1 2 10 1 2 4 24 5.6% Mound 3 5 1 1 23 1 1 5 4 44 10.3% Orono 7 2 7 20 1 7 1 6 4 55 12.9% Plymouth 7 1 8 1.9% Shorewood 9 3 7 29 1 1 3 2 15 70 16.4% Spring Park 2 4 10 3 19 4.4% St. Bonifacious 1 1 1 3 0.7% St. Louis Park 5 1 6 1.4% Tonka Bay 2 2 1 13 2 2 22 5.1% Victoria 2 1 2 1 4 10 2.3% Wayzata 5 1 2 4 12 2.8% Woodland 0 1 1 2 0.5%

TOTALS(2): 93 30 33 6 168 11 3 2 22 3 25 32 428 PERCENTAGE 21.7% 7.0% 7.7% 1.4% 39.3% 2.6% 0.7% 0.5% 5.1% 0.7% 5.8% 7.5% 100.0%

(1) A total of 279 permits were applied for in 1996. (2) Multiple rules apply to some permit applications Note: Rule K and Rule L definitions were altered during the year 1996.

Minnehaha Creek Watershed District 30 Years of Water Resources Management Page 4

Annual Hydrologic Monitoring (1968-Present) Wayzata Bay Since 1968, the District has been collecting hydrologic data Average Annual Summer Surface Values throughout the watershed on an annual basis to define watershed 0.12 hydrologic problems, provide information used in making watershed 0.10 management decisions, and evaluate how well completed projects can function. The District has built one of the best long-term water 0.08 quality and quantity data bases in the metropolitan area. The 0.06 monitoring program has been modified and expanded throughout the 0.04 years to more fully represent the quality and quantity aspects of the 0.02 District’s water resources. Since implementation in 1968, hydrologic Total Phosphorus (mg/l) 0.00 data collected includes precipitation, lake levels, stream flows, lake 1969 1973 1977 1981 1985 1989 1993 and stream water quality, and groundwater levels and water quality. Water quality trend graph showing Monitoring results have been summarized in annual hydrologic data phosphorus concentrations in Wayzata reports published by the District. Bay on Lake Minnetonka. Overall Plan for Water Management (1969) In 1969, the District’s first water management plan was prepared. The plan identified surface and groundwater problems and possible corrective actions that could be taken alleviate the problems. The plan focused on three problem areas, namely water pollution, flood control, and low water levels during dry periods. Recommendations included removing all sewage treatment plant effluent from Lake Minnetonka to improve water quality and reducing flooding along Minnehaha Creek by constructing an outlet control structure to regulate discharge from Lake Minnetonka . Elimination of Municipal Wastewater Discharges to Lake Minnetonka (1971-1986) The District worked closely with local and regional governments to eliminate wastewater discharges to Lake Minnetonka from seven municipal sewage treatment plants. Municipal wastewater discharges Water quality monitoring plays a significant role were phased out over a 15-year period from 1971-1986 resulting a in determining needed improvements as well as significant reduction in phosphorus loads to multiple streams, evaluating the performance of completed projects. wetlands, and Lake Minnetonka. A dramatic improvement in lake water quality was documented by the District's annual hydrologic monitoring.

Minnehaha Creek Watershed District 30 Years of Water Resources Management Page 5

Summary of Past Municipal Wastewater Discharges to the Lake Minnetonka Watershed

Effluent Phosphorus Start Phase-Out Flow(1) Load(2) Municipality Receiving Water Date Date (mgd) (lb/yr)

Excelsior Gideons Bay 1927 1972 0.53 8,640

Long Lake Tanager Lake/Browns Bay 1963 1980 0.31 3,160

Maple Plain Painter Creek/Jennings Bay 1951 1986 0.24 4,130

Mound Langdon Lake/Cooks Bay 1963 1974 1.37 17,880

Orono French Lake/Crystal Bay 1963 1980 0.48 2,010

Victoria Auburn Lake/Halsteds Bay 1958 1973 0.22 1,160

Wayzata Peavey Pond/Browns Bay 1939 1971 0.53 13,800

Total2 50,780 Notes: (1) Maple Plain flow in 1982. Victoria flow based on one-week field survey by MPCA in 1969. Other flows, average for two years prior to phase-out. (mgd = million gallons per day) (2) Effluent total phosphorus load in 1969-1970. (lb/yr = pounds per year)

Wayzata Wetland Study for USEPA (1975) The District pioneered a federally funded wetland study in 1975 to evaluate how well wetlands treat urban stormwater runoff and re- move nutrients such as phosphorus. A 7-acre wetland located in Wayzata with a 70-acre drainage area was selected for the study. The study defined the role natural wetlands play in the hydrologic cycle and demonstrated that wetlands are effective as a non-struc- tural treatment method in removing nutrients and contaminants con- tained in urban stormwater runoff. The wetland used in the study retained 77 percent of all phosphorus and 94 percent of the total sus- pended solids entering the site during the evaluation period. Results from the District’s wetland research were published by the U.S. EPA and became a national guidance document used in the management of urban stormwater runoff.

Minnehaha Creek Watershed District 30 Years of Water Resources Management Page 6

Construction of Gray’s Bay Dam and Outlet (1979-1980) One of the original goals of the District was to control flood damage along Minnehaha Creek. Most of the damage was occurring along the lower reach of the creek in commercial, residential, and park areas constructed within the floodplain. At the request of five communities located along the creek, the District improved the existing dam at Gray’s Bay and constructed an outlet control structure in 1979-1980. The purpose of the improvement was to manage water levels in Lake Minnetonka and reduce downstream flooding along Minnehaha Creek. The outlet control structure was constructed with three adjustable stainless steel gates to release water at a controlled rate from about May to November and is equipped with a fish screen. The recreational facilities at the Gray’s Bay Dam site were also Construction of an outlet control structure upgraded by the District as part of this project including construction and improvements to Gray's Bay Dam of a paved parking lot, picnic facilities, toilets, bike racks, drinking helped to minimize flooding to communities fountain, and canoe landing. downstream of Lake Minnetonka. Minnehaha Creek Channel Improvements at I-494 in Minnetonka (1979-1980) A section of the upper reach of Minnehaha Creek was dredged by the District in the vicinity of the I-494/Minnetonka Blvd. interchange in 1979-1980 to increase the flow capacity of the creek. This work, coordinated with the City of Minnetonka and Mn/DOT, involved lowering the creekbed by up to 2 feet by removing accumulated sediment along a 4,600-foot reach of the creek and stabilizing creekbanks.

Minnehaha Creek channel dredging at I-494.

Minnehaha Creek Watershed District 30 Years of Water Resources Management Page 7

Minnehaha Creek Recreational Improvements (1979-1980) Recreational and channel improvements along Minnehaha Creek between its headwaters and France Avenue within the cities of Minnetonka, Hopkins, St. Louis Park, and Edina were completed by the District in 1980. This work included the construction of canoe landings and portages, parking areas, picnic and sanitary facilities, bike racks, wildlife ponds, raising of pedestrian bridges, installation of culverts, and minor channel maintenance and repair.

Minnehaha Creek Channel Improvements at West 44th Street in Edina (1981) In 1981, the District dredged out a 1,300-foot section of Minnehaha Creek in the vicinity of West 44th Street in Edina. The project, funded jointly with the City of Edina, improved the flow capacity of the channel resulting in lower upstream flood elevations.

Hydraulic/Flood Study of Minnehaha Creek in Minneapolis (1982-1983) In 1980, the District completed In 1982-1983 the District and City of Minneapolis jointly undertook recreational and channel improvements a hydraulic study of flooding along a portion of Minnehaha Creek that included the installation of canoe west of I-35W. The study made use of a HEC-2 stream hydraulic landings along portions of Minnehaha model application previously developed by the U.S. Geological Creek (Utley Park canoe landing shown Survey for a flood insurance investigation. Flood impacts were above). evaluated for six existing bridges and culverts. Impacts were found to be large at three of these locations. Beneficial hydraulic effects were investigated for three possible designs proposed by the City for the Logan Avenue bridge, a larger culvert at Penn Avenue, and removal of an abandoned bridge. Reductions of up to 2 feet in 50-year flood stage were found to result from these modifications and several homes were afforded more flood protection. The study recommended a new single-span Logan Avenue bridge and a wider, higher Penn Avenue culvert. Removal of the abandoned bridge near Pleasant Avenue was not justifiable on the basis of flood impacts alone because the location is far downstream from flood-sensitive residential areas.

TR-20 Runoff Model (1983) Surface water runoff impacts many District activities including floodplain management, stream flow forecasting, lake level regulation, drainage system design, water quality control, recreation, and fish and wildlife management. The District has modeled the entire watershed using the Soil Conservation Service TR-20 computer model under the existing and unmanaged future conditions for the 1, 10, and 100-year storm events. These values assist in establishing a framework for effective water quantity management. The model was first developed for the watershed in 1983 and later updated in 1997. The extensive effort involved the modeling of 153 individual subwatersheds. Modeling results are included in the District’s water resources management plan.

Minnehaha Creek Watershed District 30 Years of Water Resources Management Page 8

Minnehaha Creek Channel Improvements at T.H. 100 in Edina (1984) Under a cooperative project with the City of Edina and Mn/DOT, the District reconstructed a 300-foot section of Minnehaha Creek upstream and downstream of the Highway 100 bridge crossing to restore the creek channel profile to that of the original bridge design plans from 1970. The project was planned and funded jointly with the City and Mn/DOT, and designed and built by the District. The channel improvements resulted in the lowering of the surface water profile upstream of Highway 100 where low-lying properties are located within the 100-year floodplain.

Painter Creek Subwatershed Improvement Project (1984-1985) Painter Creek, a major tributary to Lake Minnetonka, was known to carry large amounts of sediment and phosphorus from its 8,500 acre drainage area. During the winter of 1984-1985, the District constructed four detention basins, two sedimentation basins, and one fish barrier within the Painter Creek Subwatershed. A one mile stretch of Painter Creek was also cleaned and repaired. The project reduced nonpoint source pollution from the Painter Creek subwatershed improving water quality in Lake Minnetonka and also provided an additional 900 acre-feet of flood storage under 100-year storm Painter Marsh. conditions.

Draft Water Resources Management Plan (1987) In 1982, Minnesota Legislature adopted the Metropolitan Surface Water Management Act (Chapter 509) mandating that all watersheds within the Twin Cities Metropolitan Area be governed by a watershed management organization and that watershed management plans be prepared. In accordance with the law, the District completed a draft water resources management plan in 1987 focusing on preservation and use of natural water storage and retention systems and designed to achieve the following five basic primary objectives:

· To reduce, to the greatest possible extent, the public expenditures necessary to control excessive volumes and rates of runoff. · To improve water quality. · To prevent flooding and erosion from surface flows. · To promote groundwater recharge. · To protect and enhance fish and wildlife habitat and water recreation facilities.

The plan was submitted to various agencies for review and comment and to the Board of Soil and Water Resources for approval.

Minnehaha Creek Watershed District 30 Years of Water Resources Management Page 9

Long Lake Diagnostic/Feasibility Study (1989-1994) In 1989, the District undertook a study of Long Lake to assess its water quality (diagnostic study) and to develop a plan for water quality improvement (feasibility study). Field work included lake, stream, and storm sewer monitoring, and was conducted during the period October 1989- September 1990 (water year 1990). Long Lake was found to be in an advanced stage of eutrophication. For the 1990 summer season, Secchi transparency averaged only 3 feet, chlorophyll-a levels indicated frequent nuisance algae blooms, and total phosphorus concentrations averaged two to four times higher than is typical for unimpacted lakes in the ecoregion. The quantity of phosphorus released into the water from bottom sediments (internal load) was found to be comparable to the inputs from streams and other sources (external load); each of these loads was a little over 3,000 pounds per year. To reduce the external load, a wet detention pond was recommended along the lake’s main tributary near County Road 6 , along with upgrading of stormwater ponds in a park in the City of Long Lake. The recommendation for reducing internal load was originally enhanced aeration, but a change was later made to alum treatment. The diagnostic/feasibility study report was published in 1993, with a further report on feasibility completed in 1994.

Approval of Water Resources Management Plan (1993) After a lengthy review process, the District’s water resources management plan was approved in 1993 by the Board of Water and Soil Resources which paved the way for several District water quality improvement projects.

Gleason Creek Improvement and Flood Control Project (1993-1995) In 1994, the District completed the construction of Phase One of the Gleason Creek Improvement Project, a cooperative project with the City of Wayzata. The project involved construction of a new outlet control structure on Gleason Lake, expansion of one and creation of a second stormwater pond and extensive storm sewer improvements. The project provides significantly improved flood control along Gleason Creek and improved water quality in Lake Minnetonka. In 1995, the District completed Phase Two of the Project which focused on improving the water quality of Gleason Lake by reconstruction and enhancement of a wetland at the inlet to the lake.

Construction of this outlet structure on Gleason Lake provided improved flood control along Gleason Creek.

Minnehaha Creek Watershed District 30 Years of Water Resources Management Page 10

Twin Lakes Subwatershed Improvement Project (1995-1996) In a cooperative effort to restore water quality in the Minneapolis Chain of Lakes, the District entered into a partnership (Clean Water Partnership) with the cities of Minneapolis and St. Louis Park, the Minneapolis Park and Recreation Board, and Hennepin County. A feasibility study was performed by the District in 1994 to provide technical recommendations for watershed improvements to the Twin Lakes Subwatershed, a 1,500 acre drainage area consisting of well- developed residential and commercial areas in St. Louis Park that contribute over 50% of the flow and over 60% of the phosphorus Twin Lakes dredging. load to Cedar Lake. The goal of the project was to optimize water quality improvement of stormwater runoff entering Twin Lakes and Cedar Lake by removing phosphorus, sediment, and other pollutants naturally through physical and biological processes. Designed, built, and funded by the District, the initial phase of structural water quality improvements were completed in 1996. These improvements consisted of constructing a wet detention basin upstream of Twin Lakes and a wet detention basin/wetland system near Cedar Lake, dredging Twin Lakes, and diverting stormwater runoff.

Long Lake Improvement Project (1995-1996) The Cedar Meadows wet detention basin/ The first phase of watershed improvements, completed in 1996 as wetland system treats inflows to nearby part of the Long Lake Improvement Project, involved the construction Cedar Lake. of a large two-cell wet detention basin in Medina, on a major tributary to Long Lake, and the expansion and enhancement of two existing sedimentation basins in the City of Long Lake. A subsequent project phase including the construction of an additional wet detention basin in Orono is planned to be completed in 1998.

View prior to construction of the wet detention basin in Medina.

After construction of the wet detention basin.

Minnehaha Creek Watershed District 30 Years of Water Resources Management Page 11

Long Lake Alum Treatment (1996) Long Lake was treated with aluminum sulfate (alum) by the District in the Spring of 1996 to remove phosphorus from the water column and to retard the release of phosphorus from lake bottom sediments. By late summer of that year, water clarity in Long Lake had increased from 2 feet to 15 feet. Alum has proven to provide a safe and effective solution to control of the amount of algae present in lakes.

MDNR Outstanding Watershed District of the Year (1996) Long Lake alum application. The MCWD was honored as watershed district of the year at the 1996 Minnesota Association of Watershed Districts (MAWD) annual meeting. The Outstanding Watershed District Award was presented to the District by the Minnesota Department of Natural Resources (DNR). In presenting the award, the DNR cited four to the District’s major achievements:

· Working with the DNR on a streamlined process for obtaining general permits. · Enhancing MCWD rules to provide for better adherence to the land alteration requirements. · Adopting a wetland buffer requirement to further protect wetland resources. · Developing Minnesota’s first watershed Internet site and helping develop on Internet presence for the remaining 41 state watershed districts on the MAWD Home Page.

The District was also recognized for using regulation, education, and water resource projects in a comprehensive way to protect and improve the water resources in the most heavily populated district in the state. Thirty years of proactive management of the Minnehaha Creek Watershed has Painter Creek Subwatershed Maintenance Project provided the community with an exceptional recreational and aesthetic (1996-1997) environment. Designed to restore the flood storage capacity created by the 1985 project and enhance the water quality treatment capability, accumulated sediment was removed and the two existing basins enlarged and depend at the South Katrina and Painter Marsh sites by the District in 1997. The existing outlets were also modified to prevent blockages.

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Minnesota Landscape Arboretum Wetland Restoration (1996-1997) The “Spring Peeper Meadow Restoration” project at the University

5 of Minnesota Landscape Arboretum in Chanhassen was completed in 1997. The District provided $250,000 toward this wetland Wetland Watershed 41 restoration project which will be showcased for public learning, Boundary (Approximately 50 Acres) experiences, demonstrations, and on-going research on wetland regeneration. The site’s hydrology was restored by breaking the network of drain tiles below the soil surface. Native plant species

WETLAND were planted in the wetland basin and a boardwalk and interpretive BASIN trail constructed within the basin to provide access to the 20-acre wetland for close viewing and plant identification.

N Gray’s Bay Outlet Maintenance and Repair (1997) The overflow spillway at the Gray’s Bay outlet had fallen into disrepair over the years through erosion and settlement. Maintenance and repair of the structure was performed by the District in 1997 to ensure proper 82nd STREET and safe implementation of the existing operation plan. This work consisted of installing timber piles to stabilize the steel sheet pile weir and constructing a new weir cap; placing riprap, boulders, and Contributing to the Minnesota Landscape cobbles along the lake side of the weir; filling and grading earth Arboretum is one method the District uses material for erosion protection and to confine lake overflow to the to help promote watershed education. weir area; extending and adding fences for safety; and removing large downed cottonwood trees.

Maintenance and repairs to the Gray's Bay overflow spillway were conducted in early 1997. View of overflow spillway after completion of repairs.

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Approval of 2nd Generation Water Resources Management Plan (1997) The District’s 2nd Generation Water Resources Management Plan was approved by the Board of Water and Soil Resources in 1997. The plan identifies a series of capital improvement projects throughout the District, as well as specific strategies to reduce the continuing degradation of surface water in the watershed. The plan also reflects the District’s goals and policies for water resources management and protection, including the District’s increased emphasis on education and public participation.

Minnehaha Creek.

Please visit our Web Site at www.minnehahacreek.org

Minnehaha Creek Watershed District 30 Years of Water Resources Management