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HomeMy WebLinkAbout1995 04-27 PCP PLANNING COMMISSION AGENDA . CITY OF BROOKLYN CENTER April 27, 1995 STUDY SESSION 1. Call to Order: 7:30 pm 2. Roll Call 3. Administer Oath of Office: Kathryn Palm 4. Approval of Minutes - March 16, 1995 5. Chairperson's Explanation The Planning Commission is an advisory body. One of the Commission's function is to hold public hearings. In the matters concerned in these hearings, the Commission makes recommendations to the City Council. The City Council makes all final decisions in these matters. 6. Discussion Items: a) UPDATE ON STORM DRAINAGE ISSUES Diane Spector, Director of Public Services, will update the Planning • Commission on various storm drainage issues. Enclosed for your review are: Brooklyn Center Water Management Task Force Phase I Recommendations and Preliminary Goals and Policies; Watershed Boundary Map showing Shingle Creek Watershed and West Mississippi River Watershed Districts; and various information relating to these districts. b) ADULT USES ORDINANCE Various studies cited in the City's Moratorium Ordinance on the siting of Adult establishments will be presented to the Commission on Thursday evening. 7. Other Business 8. Adjournment • J 4 Water Management Task Force • Phase I Recommendations The Water Management Task Force has met approximately eight times since May 12, 1992. The primary functions of this Task Force were to meet with staff and the consultant (BRAA) to review information, to assist them in developing information, to provide review and comment to the analysis and recommendations of the consultant, and to assist in a prioritization process. Based on our discussions and work with City staff and BRAA, the City's consultant in preparation of the Phase I Water Management Plan, the.following are our recommendations to the City Council of the City of Brooklyn Center: RECOMMENDATION 1 Receive and approve Phase 1 of Brooklyn Center's Water Management Plan, dated April 1994, as prepared by the consultant Bonestroo, Rosene, Anderlik& Associates (BRAA). The plan will then be forwarded to the Shingle Creek Watershed Management Organization and . the West Mississippi Watershed Management Organization for their final approval. Also consider a possible project or area-specific approach to the development of Phase 2 studies, similar to the approach used recently for the preparation of Brookdale Area Storm Drainage • Plan. RECOMMENDATION 2 Update or create, as necessary, Floodplain and Shoreland Ordinances which consider the current requirements, guidelines or models of the Minnesota Department of Natural Resources (DNR), Board of Water and Soil Resources (BWSR), Metropolitan Council, U.S. Corps of Engineers, Shingle Creek and West Mississippi Watershed Management Organizations, etc. RECOMMENDATION 3 Implement Phase 2 of the Water Management Plan according to these priorities: a) Upgrade the City's storm sewer system to 5-year design standards (larger pipes, more catch basins, less cross-street gutter drainage, etc.), consistent with the majority of the Metro area municipalities. It is clearly most cost-effective to coordinate most of these storm drainage improvements with other infrastructure issues such as pavement rehabilitation and sewer or water repair/replacement. This type of work should be performed in conjunction with neighborhood street and utility improvement projects over the next 20 years, similar to what is currently underway in the Northwest Area and on James/Knox 154th Avenues. e • b) Aggressively pursue the development of regional storm water treatment ponds by acquisition of land for, and if necessary by purchasing lands with Storm Drainage • Utility monies, storm water management facilities, to address water quality and quantity issues in a proactive, comprehensive manner. As commercial and industrial areas redevelop, and infrastructure is upgraded or replaced, the storm water quality requirements of the West Mississippi and Shingle Creek Watersheds will require that the redeveloper (in some cases the City) treat its storm waxer runoff in a permanent pond. The literal interpretation and application of the Watersheds' rules would require an individual pond on each developing or re-developing commercially- used property larger than S acres, and for each residentially-used area exceeding IS acres. It is then the City's responsibility to enforce the on-going maintenance and clean- up of these ponds, which can be very difficult in commercial areas as these types of properties often change ownership/management. Fewer, larger, more accessible facilities would be easier to monitor and maintain, and generally would have a better chance of making a difference in the quality of storm water that eventually reaches our lakes, rivers and streams. The regional pond to be located just west of the MTC Park and Ride at 65th and Brooklyn Boulevard is such an example. This pond will serve a large portion of the west part of the City. The Brookdale Storm Water Study includes a regional pond option to be located just south of the Centerbrook Golf Course. This pond would benefit a large portion of the south central portion of the City, including the Brookdale shopping center. c) Projects, either regional or local, which specifically address enhancing the water quality and aesthetic, recreation or wildlife value of Twin Lake(s), Palmer Lake, Ryan Lake, Shingle Creek and the Mississippi River. • These types of projects might include an increased level of water quality monitoring in conjunction with the efforts of the Watersheds; aquascaping demonstrations; working with the DNR in evaluating and enhancing the gamefish populations;and water quality improvements targeted toward the enhancement of swimming or boating opportunities. d) Ensure that all new habitable buildings are protected from flooding from a 100 year rainfall event. The Watersheds are committed to the promotion and evaluation of candidate,flood- proofing projects near the major waterways, the City should coordinate its efforts accordingly. e) Other specific projects or activities to be identified by the Task Force. RECOMMENDATION 4 The City should examine all currently available and potential fund sources for future storm water quality and quantity improvements. For example, consideration should be given to revising the City's current street assessment philosophy to include costs for at least a minimal or baseline amount of lateral storm drainage improvements . Page 2 • • Air • Currently the Storm Drainage Utility is funding all aspects of the City's efforts to upgrade its system. The preliminary cost which has been identified for the development of a regional • storm water facility south of the golf course exceeds $2,000,000; some combination of Storm Drainage Utility, special assessments, Tax Increment Financing and user fees will be necessary for the financing. Also, it is estimated that the storm drainage costs alone for the Northwest Area street and utility project this year will amount to $600,000, all of which will be paid from the Storm Drainage Utility. Because of the relationship between drainage conditions and pavement maintenance costs, it is appropriate to consider the inclusion of some provision for storm drainage improvements in the standard street assessment rate. RECOMMENDATION 5 The City should continue to appropriate monies from the Storm Drainage Utility for an on-going program of public education for surface water related issues. Possible activities/programs include newsletters, press releases, videos, demonstrations and other media which promote greater awareness of non point pollution and nutrient sources such as fertilizer, pesticides, grass clippings, road sand and salt, automotive chemicals, soil, etc. RECOMMENDATION 6 The City should continue to work together with other cities and agencies to effectively implement the components of the Local Plan. Respectfully submitted, WATER MANAGEMENT TASK FORCE Graydon Boeck Jon Perkins Bill Siems Kristen Mann, Council Liaison Page 3 • 1.2 Goals and Policies FREL ' -AF R Y • The foundation of Brooklyn Center's Water Management Plan (WMP) is the goals and policies upon which the City-wide plan is based. The goals and policies were established under the guidance of a Task Force made up of City staff and residents. Initially, the Task Force established the following objectives for the WMP: Water Management PIan Objectives a) To reduce to the greatest practical extend the public capital expenditures necessary to control excessive volumes and rates of runoff b) To improve water quality c) To prevent flooding d) To reduce erosion and sedimentation from surface flows e) To promote groundwater recharge f) To protect and enhance fish and wildlife habitat g) To provide water recreational opportunities h) To enhance the natural beauty of the landscape i) To secure the other benefits associated with the proper management of surface water Based on the WMP objectives, the Task Force developed a set of goals and policies for the City of Brooklyn Center. A goa12 is a desired end toward which the City's policies, standards, criteria, and rules are directed. A policy is a governing principle, a means of achieving an established goal. Policies prescribe a general course of conduct that leads toward goal achievement. As with all planning tools, these goals and policies are meant to be dynamic and flexible and to evolve with changing conditions in the City. 2 Note that the numbering system of the goals does not imply ranking by priority. • 1 -4 J • • , PREL Goal I To develop a hydrologic and hydraulic model that relates runoff to the existing and planned land • use within Brooklyn Center. Policy 1.1 Develop a WMP that accommodates the existing land use in Brooklyn Center. Policy 1.2 Develop a VW that is flexible in incorporating future redevelopment. Goal 2 To preserve, obtain, and use storage.and retention areas for maintenance and improvement of the hydrologic systems within Brooklyn Center. Policy 2.1 Preserve existing storage capacities of protected waters and wetlands and natural watercourses. Policy 2.2 Coordinate the preservation and enhancement of storage areas with state, county, and neighboring municipal agencies. Policy 2.3 Lirn;E development runoff rate to the projected management plan rate for each • subwatershed. Policy 2.4 Provide for additional storage either on site or within the subwatershed where necessary to comply with the VW. Policy 2.5 Consider other forms of runoff volume and rate control where necessary to comply with the WNIP. Goal 3 To reduce to the greatest exten*possible t4blic capital and maintenance expenditures necessary to control excessive volumes and rates of runoff. Policy 3.1 Implement the most efficient and effective methods to limit public costs, as provided in the WN1P. Policy 3.2 Coordinate street and other reconstruction projects with VW improvements. • 1 - 5 Goal 4 + � RY To maintain or improve both surface water and groundwater quality. • Policy 4.1 Promote the treatment and/or control of runoff to enhance water quality by reducing nutrient and sediment loadings. Policy 4.2 Preserve and protect wetlands which provide natural treatment for runoff where necessary to comply with the VW. Policy 4.3 Establish a water quality monitoring system for identifying changing conditions and potential problems. Policy 4.4 Protect groundwater recharge areas from potential sources of contamination. PoIicy 4.5 Promote or establish a program to reduce discharge of substances contributing to water quality degradation. Goal 5 To prevent and control flooding damage. • PoIic y 5.1 Prohibit encroachment without acceptable mitigating action that will reduce the storage capacity of floodplains. Policy 5.2 Allow only structures that have been flood-proofed or will not be subject to excessive damage in the floodway Tinge. This recognizes that there are existing non-conforming uses within the floodway fringe. Goal 6 To control erosion and sedimentation. Policy 6.1 Nfinimize runoff velocities and maximize natural cover to reduce erosion. Policy 6.2 Require all measures necessary to effectively control sediment and erosion within construction sites. • 1 - 6 • • J 1 • Goal ? To promote groundwater recharge. • PoIic y 7 .1 Evaluate and control (re)development over groundwater recharge areas. Goal 8 To protect and enhance water related fish and wildlife habitats. Policy 8.1 Promote and adoption of those aspects of local shoreland regulations that enhance fish and wildlife habitat. Policy 8.2 Preserve protected waters and wetlands that provide habitat for game fish spawning and wildlife. Policy 8.3 Coordinate with'the DNR to enhance fish and wildlife habitats. PoIicy 8.4 Coordinate with the DNR to protect rare and endangered species. Goal 9 • To protect and enhance opportunities for water recreation. Policy 9.1 Coordinate with the state, counties, and neighboring municipalities to enhance water-based recreation. Goal 10 To coordinate and communicate among agencies, adjacent communities, and citizens which affect water management within Brooklyn Center. Policy 10.1 Coordinate activities of the City and citizens relating to water management. PoIicy 10.2 Work closely with adjacent communities in planning and developing mutually beneficial stormwater management improvements. • 1 - 7 la Goal 11 To provide a reasonable level of stormwater protection within the City. • Policy 11.1 Establish a 5 year rainfall event as the minimum criteria for all new stormwater conveyance facility designs. Policy 11.2 When upgrading existing stormwater facilities, provide a 5 year level of service to the upgraded portions drainage area. Policy 11.3 Ensure that all new habitable structures are protected from flooding during a 100 year rainfall event. These goals and policies are intended to incorporate the spirit of several Regional, State and Federally mandated programs. They are not meant to replace or alter these programs, rules and regulations,,but serve as an enhancement and provide some general policy guidelines. The goals address the management strategies of both watershed management organizations, West Mississippi and Shingle Creek, and are consistent with the objectives set forth in the State Wetland Conservation Act (WCA) and the Federal National Urban Runoff Program (NURP). 1.3 Stormwater Quantity and Quality Stormwater runoff is defined as that portion'of precipitation which flows over the ground surface during, and for a short time after a storm. The quantity of runoff is dependent on the intensity of the storm, the amount of antecedent rainfall, the length of the storm, the type of surface the rain falls on and the slope of the surface. The intensity of a storm is described by a return storm interval or frequency of occurrence. The return storm interval is the average period of years within which a storm of a certain magnitude is expected to occur one time. Thus, the degree of protection is determined by selecting a return storm interval for the basis of design. For the Brooklyn Center Water Management Plan, a five year frequency storm event is used for the storm sewer design, while a 100 year frequency event is used for overland drainage and pond storage design. A five year frequency storm (3.6 inches in 24 hours) has a 20% chance of occurring or being exceeded in any given year whereas a one hundred year frequency storm (6 inches in 24 hours) has a 1% chance of occurring or being exceeded in any given year. Complete protection against large, infrequent storms with return intervals greater than 100 years are typically justified only for important flood control projects. For fully developed areas like Brooklyn Center, the cost of construction or rehabilitation of a large capacity storm drainage 1 - 8 "FRI 11111 ,, r � ` E� MA WIN •iiiii.. •: t ���•...� :off+�:' _;�,�\,`, 11111111 1XI pill -: 111 �j;�! IIIIIIIIIIII����II�IIIIQ'T1'��3�11 ' j • I x A.:d"A AVA.L&aL-7A&-MJA.1 A. A V T L'AA ALLLL 7A-L."L MANAGEMENT COMMISSION REVIEW CRnMRU Fleedelain Dev loom vet The Commission requires that the following types of matters be reviewed: 1. There shall be no encroachment upon the ioodway area of the 100-year floodplain as defined is Section 3 of the Watershed Management Plan or •1. Plans of any land development, or individual site development adjacent determined by the'Flood Insurance Study for the various member cities. to or within a lake,wetland,or a natural or altered natural watercourse alterations of the IIoodway may be proposed subject to approval of the as Bated in the final inventory of Protected Waters and Wetlands for Commission and the Minnesota Department of Natural Resources. Hennepin County,as prepared by the State of Minnesota Department of Natural Resources. 2. Encroachment shall be allowed in the floodway fringe area of the 100- 2. Plana for any land development,or site development within the 100-year year floodplain only if both of the following conditions are met: floodplain as defined in Section 5 of the Watershed Managemeat Plea or a. Compensatory storage is provided is the 100-year floodplain of equal determined by the-Flood Insurance Study-for the various member cities. or greater volume than that removed by the encroachment upon the IIoodway fringe. 3. Pleas of any land development,or site development of 15 acres or larger for single family detached housing use and 5 acres or larger for all other b. The encroachment does not create hazardous velocities. land uses. 3. Buildings within or adjacent to the 100-year floodplain shall be 4. Plans of any land development•or site development regardless of size,if constructed so that the elevation of the lowest floor is a minimum of LO such review is requested by a member city. feet above the 100-year flood elevation as defined in Section 5 of the S. Land use amendments to a d Watershed Management Plan or determined by the 'Flood Insurance ty`s comprehensive p� Study'for the various member cities. The LO feet of required&aeboard is intended to allow for the increase in flood elevations as a result of *Land development is defined to include building additions,site expansion,or future to and development provide a factor of safety for wind and wave redevelopment of existing sites. P action. 3L%XAG&NIMU STANDARDS 4. all site areas below the 100-year floodplain elevation after approval of allowable encroachments shall be preserved and dedicated for flood Development Adiacent to or Within a Protected Water or Welland storage by means of granting an appropriate easement to the respective 1. There shall be no area encroachment upon the Protected Water or city. Wetland or rough grading below the ordinary high water mark(OHW) Develeemmt of 1S Acres er L.arver fer Sinele Family Detached without approval of the Commission and the Minnesota Department of Hoe.in¢ IT.e and S Acres or L.arrer fer Other Land Uses (e.s_. Natural Resources. ('e ,n rri 1Rnd•.trial Situ.Ghee 2. Design of encroachments. when permitted, shall provide compensatory 1. Development plans shall contain permanent provision for treatment of volumes of equal or greater volume than that removed by the stormwater runoff. Such treatment shall consist of providing a ponding encroachment and compensatory areas to offset the elimination of area adequate in size to store runoff from a Mach rainfall event based vegetation providing biological treatment of stormwater runoff and upon a fully developed site. A minimum permanent pool depth of 2 fact wildlife habitat. shall be maintained in the required pending area In lieu of individual treatment ponds, a central retention pond may be used if sized to store Development plans for properties adjacent to a Protected Water or the collective runoff of all contributory areas for the 2-inch rainfall Worland shall contain provisions for temporary erosion and sediment event. Pond discharge shall be limited to that required for the pond to control that will prevent deposition of sediment into the Protected Water empty no sooner than 6 hours after the rainfall event In addition, a or Wetland during the development process. means of retaiaiag oils and doatable debris shall be provided in a manner acceptable to the Commission 4. Development plans for properties of 2.3 acres or greater, not including individual residential lots, shall contain permanent provisions for 2. Development plans shall contain provisions for temporary erosion and treatment of stormwater runoff. Such treatment shall consist of sediment control that will prevent soil particles from being transported providing a ponding area adequate in size:to store runoff from a 2-inch off the site using standards prescribed in the 'Erosion and Sediment rainfall event based upon a fully developed site. The required pending Control Manual,'as prepared by the Hennepin Conservation District. area shall have a minimum permanent pool depth of 2 feet. In lieu of individual treatment ponds,a central retention pond may be used if sized 3. 411 site areas used for the to store the collective runoff of all contribute areas for the 2-inch Pnspeae d flood storage or treatment of contributory stormwater runoff shall be preserved and dedicated for that use by mesas rainfall event. Pond discharge shall be limited to that required for the of granting an appropriate easement to the respective city, including pond to empty no sooner than 6 hours after the rainfall event. In areas required for access to maintain the easement. addition,a means of retaining oils and floatable debris shall be provided in a meaner acceptable to the Commission. 4. Development plans shall'contain provisions that designate operation and 3. All site areas used for the purpose of flood storage or treatment of maintenance procedures which will maintain outlet control structures P ripe g and a minimum permanent pool depth of 2 feet and provide assurance to stormwater runoff shall be preserved and dedicated for that use by means the appropriate member city,in the form of a recordable agreement,that of granting an appropriate easement to the respective city, including such operation and maintenance procedures will be faithfully executed. areas required for access to maintain the easement ch—Jr T t Please submit the appropriate ezhebit(s)listed below with your pmiect review application. ❑ Project location map ❑ Brief summary describing existing site drainage prior to development sad propowd site drainage. ❑ Stormwater Management Plan(grad;:g and dram age plan.rte-) ❑ Drainage calculation, ❑ Compensatory storage calculations ❑ Temporary erosion and sedimentation control plan and details ❑ Ocher • • r SHINGLE CREEK WATERSHED MANAGEMENT PLAN f EXECUTIVE SUMMARY • INTRODUCTION The 1982 Minnesota Legislature adopted the Metropolitan Surface Water Management Act (Statutes 473.875 to 473.883) mandating that all watersheds within the seven county metropolitan area be governed by a watershed management organization. In 1984, the nine cities who have land in the Shingle Creek Watershed, namely, Brooklyn Center, Brooklyn Park, Crystal , Maple Grove, Minneapolis, New Hope, Osseo, Plymouth, and Robbinsdale, entered into a Joint Powers Agreement and formed the Shingle Creek Watershed Management Commission to plan, control , and provide for the development of the Shingle Creek Watershed. This organization has since embarked on its duties and responsibilities as mandated by the Minnesota Legislature to prepare this watershed management plan focusing on the preservation and use of natural water storage and retention systems. In 1987, the legislature amended the act to include specific responsibilities for groundwater management and the act was retitled the "Metropolitan Water Management Act." Under the authority of 'the Metropolitan Water Management Act and the Joint Powers Agreement, the Commission will administer the regulatory functions of this watershed management plan through providing the framework for local water management plan content and regulatory functions. The Commission has elected to initiate programs and promote participation in areas where an effort at the watershed level would most appropriately and cost effectively be implemented. The administering agencies for the regulations contained in the local plans will be the local governmental units. Specific zoning and land use planning as well ' as plan implementation responsibilities remain with the individual cities. The Commission will be responsible for insuring that the municipalities properly and consistently implement their local management plans. Where issues concerning more than one municipality cannot be resolved through efforts at the local level the Commission will , upon request of the municipalities, act to settle such issues. Local Water Management -Plans. The Act further requires that after adoption of the watershed management plan, local government units having land use planning and regulatory authority for territory within the watershed shall prepare a local water management plan, capital improvement program and official controls as necessary to bring local water management into conformance with the watershed management plan. Although no time period is specifically prescribed for completion of the local water management plan, the Commission is requiring that local water management plans be completed within 3 years of the adoption of the Shingle Creek Watershed Management Plan. Local government units must also prepare amendments to the local comprehensive plan required to bring official controls in conformance with the watershed management plan. After completion, local water management plans shall be submitted to the Commission for approval . WATERSHED DESCRIPTION The Shingle Creek Watershed covers an area of 43.5 square miles in east-central Hennepin County. This kidney-shaped watershed extends approximately 10 miles from Plymouth and Maple Grove in the west to Minneapolis in the east. Shingle Creek begins at the junction of Bass Creek and Eagle Creek in Brooklyn Park, v v • flows easterly, then southerly for a total of 11.3 miles before discharging into the Mississippi River at Minneapolis. There are a number of lakes and wetlands within the Shingle Creek Watershed. Major recreational lakes include Bass Lake, Crystal Lake, Eagle/Pike Lake, and Twin Lakes. In the eastern three-quarters of the watershed, the land is predominantly urban in nature and in the western • one-quarter of the watershed, it is now mostly rural, but rapidly developing. PLAN CONTENTS This watershed management plan provides a detailed inventory of the physical and hydrologic characteristics of the watershed. The TR-20 and HEC-2 computer models were used to assist in the hydrologic evaluation. The plan also establishes objectives and policies for water management, identifies management issues and strategies, and proposes an implementation program to accomplish these strategies. MANAGEMENT ISSUES AND STRATEGIES Eight important management issues have been identified in Chapter V of the plan. They include: 1. Runoff Management 2. Floodplain Management 3. Shoreland Management 4, Water Quality Monitoring 5. Erosion and Sedimentation Control 6. Stormwater Treatment 7. Wetlands Management 8. Groundwater Protection ' Strategies have been developed to address each issue while meeting the objectives and policies set forth by the Commission. Procedures are identified for implementing the strategies in the form of projects, plans and programs. The responsibility and level of participation of each governmental unit and the Commission are also identified. Below is a brief summary of the management strategies developed by the Commission and the action chosen to address each issue. Runoff management is necessary to resolve current flooding problems and accommo ate future land use changes. The lower portion of the watershed is fully developed and the flooding of residences that now occurs will increase with further upstream urbanization unless the pressures on the drainage system can be reduced. The Commission has established allowable peak outflow rates for runoff management sectors. The runoff management sectors are composed of aggregates of subwatersheds. The Commission will ensure that the drainage system's conveyance and storage capacities are adequate to prevent the allowable rates from being exceeded. Key storage components will be preserved, improvements affecting storage capacities will be regulated, and drainageway capacities will be maintained and monitored. These strategies will be accomplished primarily through local watershed management plans. vi • • r Floodplain management is necessary to maintain sufficient flood storage capacity • to m— i mize flood-related property damages. Encroachment within the floodplain results in higher flood elevations and increased velocities. Runoff management f issues in this watershed indicate critical need for sound floodplain management. The strategy of the Commission is to prohibit encroachment within the 100-year • floodplain except where actions that mitigate adverse impacts have been taken. The Commission will administer the floodplain management program and review all projects proposed within the 100-year floodplain. Floodplain management strategies shall be incorporated into the local water management plans. Shoreland management is necessary to ensure future water quality. It is proposed to be achieved through the adoption of local shoreland protection ordinances that are consistent with Minnesota Department of Natural Resources' regulations. Water quality monitoring will be performed in accordance with a long-term plan to identify problems and protect the quality of the lakes and streams. Limited water quality data currently exists for the watershed, and data that is available is insufficient to properly analyze overall water quality at the level of detail necessary for watershed management. Stream and lake monitoring programs will be developed to establish baseline information and to initiate programs to maintain or improve water quality. A treatment program may be considered if data indicates it is warranted. Erosion and sedimentation from agricultural or urban land development can degrade water quality, obstruct flow, and reduce the depth of downstream waterbodies in the watershed. The Commission will support the efforts of the Hennepin Conservation District and the U.S. Department of Agriculture, Soil Conservation Service in addressing soil stabilization within the watershed. The Commission requires that members adopt erosion and sedimentation control ' measures that meet Management Standards. A review program must be established for all land development construction site work as a part of the local plan. Stormwater treatment is necessary to reduce water quality problems in the system and protect waters that recharge groundwater supplies. This would primarily include reducing the amount of sediments and nutrients that enter streams via a stormwater system. Each municipality shall prepare a local water management plan in conformance with Shingle Creek Watershed Management Commission requirements. These plans must demonstrate that treatment is provided for stormwater runoff prior to its discharge into any public water. Existing development is required to provide treatment as part of a redevelopment or as designated by the Commission or local plan. Wetland management will preserve "protected waters" and ensure a long-term role for wetlands in stormwater treatment. The Commission will consider the water storage and nutrient assimilative ability of wetlands not under DNR jurisdiction and help assist municipalities in determining their proper use. Protected waters and wetlands as defined in the Public Waters and Wetland Inventory of Hennepin County will be managed through coordination with DNR programs. vii i, • Wetland development guidelines will be established to preserve treatment characteristics of wetlands not under DNR jurisdiction. To assure compliance with development guidelines, the Shingle Creek Watershed Management Commission • may also require local water management plans to include a program to manage certain wetlands not included in the DNR's protected waters and wetlands inventory and enforce compliance. Groundwater protection is an important concern in the watershed. Of the nine communities in the watershed, three rely partially or entirely on drift wells, two use both bedrock aquifer and drift wells, and four rely entirely on bedrock aquifers. The Commission will establish a procedure to review and comment on development that may affect groundwater quality and quantity. Procedures will be adopted by local governmental units level to control development that may affect groundwater resources. SUPPLEMENTAL STUDIES Three supplemental studies have been proposed to better define allowable peak outflow rates and storage requirements. They include: Twin Lakes/Ryan Lake Outlet Modification-Final Evaluation, Eagle Lake Outlet Channel Capacity Analysis, and Crystal Lake Outlet Feasibility Study. These studies are currently being completed or scheduled for completion in 1989 and will likely result in capital improvements. FUNDING Capital improvements will be funded under the provisions of Section VII and VIII of the "JOINT AND COOPERATIVE AGREEMENT FOR THE ESTABLISHMENT OF A SHINGLE CREEK • WATERSHED MANAGEMENT COMMISSION". General funds of the Commission are to be used for administrative purposes including local plan review, amendments to local plans and audits of municipal records. PLAN OVERVIEW This plan is a dynamic document which reflects public concerns. It is intended to be a guide and working tool to member units of government in managing the water resources of the Shingle Creek Watershed. This plan is subject to review and will be updated as the needs and accomplishments of the Shingle Creek Watershed Management Commission dictate. RESPONSIBILITY FOR PLAN CONTENTS In April 1988, E. A. Hickok and Associates, Inc. was acquired by the firm of James M. Montgomery, Consulting Engineers, Inc. All references to E. A. Hickok and Associates, Inc. in the Plan have not been deleted and the reader is advised that James M. Montgomery, Consulting Engineers, Inc. assumes full responsibility for the contents of this plan. viii • • r ` 0 > z w z w d a w z � z z > z w z w z z z z 3 V7 ' Z z o N ma a �' Fn Z a z w z w w z w z U C7 W a $ E' • F a m y < 3a Z!l rl U W V � ° gS y w w z w w z z 2 z � A 4 z 2 z w O X U a. pa O a O� V ggo�G � �y � X � -,')1 oC m z VI-3 WEST MISSISSIPPI WATERSHED MANAGEMENT PLAN EXECUTIVE SUMMARY • INTRODUCTION The 1982 Minnesota Legislature adopted the Metropolitan Surface Water Management Act (Statutes 473.875 to 473.883) mandating that all watersheds within the seven county metropolitan area be governed by a watershed management organization. In 1984, the five cities who have land in the West Mississippi Watershed, namely, Brooklyn Center, Brooklyn Park, Champlin, Maple Grove, and Osseo, entered into a Joint Powers Agreement and formed the West Mississippi Watershed Management Commission to plan, control , and provide for the development of the West Mississippi Watershed. This organization has since embarked on its duties and responsibilities as mandated by the Minnesota Legislature to prepare this watershed management plan focusing on the preservation and use of natural water storage and retention systems. In 1987, the legislature amended the act to include specific responsibilities for groundwater management and the act was retitled the "Metropolitan Water Management Act." Under the authority of the Metropolitan Water Management Act and the Joint Powers Agreement,, the Commission will administer the regulatory functions of this watershed management plan through providing the framework for local water management plan content and regulatory functions. The Commission has elected to initiate programs and promote participation in areas where an effort at the watershed level would most appropriately and cost effectively be implemented. The administering agencies for the regulations contained in the local plans will be the local governmental units. Specific zoning and land use planning as well as plan implementation responsibilities remain with the individual cities. The Commission will be responsible for insuring that the municipalities properly and consistently implement their local management plans. Where issues concerning more than one municipality cannot be resolved through efforts at the local level the Commission will , upon request of the municipalities, act to settle such issues. Local Water Management Plans. The Act further requires that after adoption of the watershed management plan, local government units having land use planning and regulatory authority for territory within the watershed shall prepare a local water management plan, capital improvement program and official controls . as necessary to bring local water management into conformance with the watershed management plan. Although no time period is specifically prescribed for completion of the local water management plan, the Commission is requiring that local water management plans be completed within 3 years of the adoption of the West Mississippi Watershed Management Plan. local government units must also prepare amendments to the local comprehensive plan required to bring official controls in conformance with the watershed management plan. After completion, local water management plans shall be submitted to the Commission for approval . WATERSHED DESCRIPTION The West Mississippi Watershed covers an area of 23.5 square miles in northeastern Hennepin County. The watershed consists of two areas; a triangular area north of 85th Avenue and T.H. 152, east of T.H. 52/169, and bounded on the north by the Mississippi River; and a rectangular area extending south along the Mississippi River .from 85th Avenue to 53rd Avenue. The triangular area is • largely rural with pockets of urban development while the lower section of the v Y • • l • watershed is predominantly urbanized. Much of the watershed drains directly to the Mississippi River. Portions of the watershed are drained by Oxbow Creek and Edinbrook as well as a trunk storm sewer system in southern Champlin, all of which outlet to the Mississippi River. There are no recreational lakes within the watershed, however, there are a number of wetland areas located in Brooklyn Park and Champlin. PLAN CONTENTS This watershed management plan provides a detailed inventory of the physical and hydrologic characteristics of the watershed. The TR-20 computer model was used to assist in the hydrologic evaluation. The plan also establishes objectives and policies for water management, identifies management issues and strategies, and proposes an implementation program to accomplish these strategies. MANAGEMENT ISSUES AND STRATEGIES Eight important management issues have been identified in Chapter V of the plan. They include: 1. Runoff Management 2. Floodplain Management 3. Shoreland Management 4. Water Quality Monitoring 5. Erosion and Sedimentation Control 6. Stormwater Treatment 7. Wetlands Management 8. Groundwater Protection Strategies have been developed to address each issue while meeting the objectives and policies set forth by the Commission. Procedures are identified for implementing the strategies in the form of projects, plans and programs. The responsibility and level of participation of each governmental unit and the Commission are also identified. Below is a brief summary of the management strategies developed by the Commission and the action chosen to address each issue. Runoff management is necessary to resolve current flooding problems and accommodate future land use changes. Stormwater surcharges occur at several locations following a significant rainfall and indicates that existing stormwater management is not adequate and modifications may be necessary. The Commission has established allowable peak outflow rates from runoff management sectors draining to Oxbow Creek, Edinbrook and the trunk storm sewer system in Champlin. Runoff management sectors are composed of aggregates of subwatersheds. Peak flows were determined for those subwatersheds draining directly to the Mississippi River. Overflow routes shall be designated to accommodate excess runoff where peak outflow rates exceed flow capacity at the outlet. The Commission will ensure that the drainage system's conveyance and storage capacities are adequate to prevent the allowable rates from being exceeded. Key storage components will be preserved, improvements affecting storage capacities will be regulated, and drainageway capacities will be maintained and monitored. These strategies will be accomplished primarily through local watershed management plans. vi > z w z m x a R Q > z m m z a 3 � z 00 a wcp a 0 Z W A W 0 � lo. to o id a a < q a � � y < � m C6 cn Yn1 3 z ; ca a w � w �a g a y z � a O z G a > OZ o � m m z VI-2 Adopted 3-10-94 • SHINGLE CREEK WATER MD MANAGEMENT CoMUSSION WETLAND MANAGEMENT POLICY Introduction Wetlands are an extremely valuable resource in the Shingle Creek Watershed. They are instrumental in providing habitat for fish and wildlife, serve as groundwater recharge areas and provide for the storage of stormwater runoff. Wetlands have also been identified as areas that have the ability to remove nutrients, solids, and other pollutants from stormwater runoff. Management Strategy The Shingle Creek Watershed Management Commission will administer the Permanent Program of the Minnesota Wetland Conservation Act of 1991 beginning January 1, 1994 as set forth in Resolution No. 93-7 adopted by the Commission on November 9, 1993. The following wetland management strategies have been adopted by the Commission: 1. Wetlands within the Shingle Creek Watershed will be managed in accordance with the Permanent Rules (Minnesota Rules 8420, as amended) of the Wetland Conservation Act as published by the Board of Water and Soil Resources (BWSR) • on June 6, 1993 and the policy outlined herein. 2. Standards and procedures for making wetland exemption and no-loss determinations, and for evaluating wetland replacement plans will be followed in accordance with the Minnesota Rules 8420. The Commission will ensure that all possibilities to avoid and minimize adverse wetland impacts have been evaluated before consideration or approval of wetland replacement plans. 3. Wetlands as defined by the Public Waters and Wetland Inventory of Hennepin County and the U.S. Fish and Wildlife Service National Wetlands Inventory will be managed through continued coordination with DNR and U.S. Army Corps of Engineers programs. Responsible Governmental Unit The Shingle Creek Watershed Management Commission shall serve as the local governmental unit (LGU) for administering the .Permanent Program under the Minnesota Wetland Conservation Act unless member cities wish to serve as the LGU. At this time, the cities of Brooklyn Park, Crystal, Maple Grove, New Hope, and Plymouth have notified BWSR and the Commission of their intent to serve as the LGU. Member cities serving as the LGU may request the Commission and its technical staff to provide assistance in the administration of the Wetland Conservation Act while retaining full LGU responsibility in making final decisions on wetland exemption and no-loss determinations and approval of replacement plans. A • • SCWMC Wetland Management Policy Implementation • The Shingle Creek Watershed Management Commission will administer the Wetland Conservation Act in accordance with Minnesota Rule 8420, which is hereby incorporated by reference as part of this policy. The Commission has permit authority in the alteration of any Type 1-8 wetland as defined in the U.S. Department of the Interior Fish and Wildlife Circular No. 39 and inventoried in the National Wetland Inventory (NWI). Areas shown on the NWI map and State Protected Waters Inventory (PWI) map are presumed to indicate the presence of a wetland. The Wetland Conservation Act does not apply to DNR protected waters and wetlands. Wetlands not shown on these maps may also exist within the watershed, and are hereby protected under all of the terms and provisions of this policy. The NWI and PWI maps show only the general location of wetlands. An on-site wetland determination will usually be necessary to establish the jurisdictional boundary of wetland areas. Each member city shall maintain a copy of the NWI map covering their corporate boundaries at their official meeting place and provide a copy of the map in their local water management plan. Member cities shall notify all parties proposing land alteration activities affecting wetland areas (e.g., dredging, filling, draining, etc.) that they are also subject to DNR and U.S. Army Corps of Engineers jurisdiction and may require a permit for such activities. Review of alterations to DNR protected waters and wetlands may be waived by the Commission when a separate permit is required by the DNR. Combined Project Notification Form for Wetland Activities The Combined Project Notification (CPN) form prepared by BWSR (revised 10/93) should • be completed by the applicant describing proposed wetland activities within the Shingle Creek Watershed and mailed to the federal, state, and local agencies who may have jurisdiction over the proposed wetland activity. CPN forms are available from each member city, the Commission office, and the Hennepin Conservation District office. The Hennepin Conservation District also serves as, the "clearing house" for wetlands information including NWI maps, soil surveys, aerial photography, and SCS wetland determinations. Exemption and No-Loss Determinations Exemption and no-loss determinations will be made by the Commission in accordance with Parts 8420.0210 and 8420.0220 of the permanent rules. The landowner is responsible for submitting the necessary information and documentation to the Commission in order to make such determinations. Wetland Delineations The "Federal Manual for Identifying and Delineating Jurisdictional Wetlands" (January 1989) shall be used as the primary technical guide. The applicant shall be responsible for establishing locations, boundaries, and type of wetlands. Wetland determinations shall be made by a qualified consultant knowledgeable and trained in applying methodologies of the Federal Manual. Winter delineations conducted under frozen or snow covered conditions will generally not be accepted. Documentation supporting all wetland delineations shall be made available to the Commission upon request. All costs associated with wetland delineations shall be the responsibility of the applicant. Questions concerning public values, location, size, or type of wetland may be submitted to a technical evaluation panel. The technical evaluation panel, composed of staff members from the BWSR and Hennepin Conservation District, and the Commission's engineer, shall make technical determinations and recommendations. -2- SCWMC Wetland Management Policy Wetland Replacement • Standards and procedures for evaluating wetland replacement plans will be followed in accordance with Parts 8420.0500-8420.0550 of the permanent rules. A wetland replacement plan application must be completed and sent to the Commission along with plans and supporting project information. Application forms are available from each member city, the Commission office, and the Hennepin Conservation District office. Before consideration or approval of a wetland replacement plan, the applicant must clearly demonstrate that all possibilities to avoid and minimize adverse wetland impacts have been evaluated. The required sequencing analysis to be completed by the applicant must demonstrate that the proposed activity impacting a wetland has complied with the following principles in descending order of priority: 1. Avoids direct or indirect wetland impacts. 2. Minimizes wetland impacts by limiting the degree or magnitude of wetland activity. 3. Rectifies wetland impacts by repairing, rehabilitating, or restoring the affected wetland. 4. Reduces or eliminates wetland impacts over time by preservation and maintenance operations. 5. Replaces unavoidable wetland impacts by restoring or creating substitute wetlands • having equal or greater public value.. For projects impacting wetland areas less than 0.1 acres, the Commission may provide an on-site sequencing' determination without written documentation from the applicant. When there are no:feasible or practical alternatives to avoid wetland impacts, wetlands must be replaced by restoring or creating wetlands located within the same subwatershed unless otherwise approved by the Commission. Wetland replacement areas shall be completed prior to or concurrent with the actual alteration of a wetland. Easements will be required over existing and replacement wetland areas. Such easements shall be conveyed to the member city in which the project is located. Wetland replacement plans are not required for those wetlands specifically exempt from the Wetland Conservation Act as listed in Part 8420.0120 of the permanent rules. Wetland Replacement Monitoring In accordance with Parts 8420.0060-8420.0630 of the permanent rules, annual monitoring reports shall be prepared and submitted to the Commission by the applicant for 5 years following completion of the wetland replacement project to ensure that replacement wetlands achieve the goal of replacing lost wetlands. Annual reports shall include comparison of as-built specifications versus design specifications, hydrology measurements, list of dominant vegetation in the wetland, and color photographs of the project area taken between June and August. Appeals Decisions by the Commission may be appealed to the Board of Water and Soil Resources as provided under Part 8420.0250 of the permanent rules. -3- SCWUC Wetland Management Policy Notification of Wetland Replacement Plans and Invitation for Comments • Notification of wetland replacement plans and invitation for comments will be made in accordance with Part 8420.0230 of the permanent rules. As provided in the permanent rules, the Commission will publish a general notice in the Environmental Quality Board Monitor once a year stating that small individual wetland impacts will not be published but instead, will be mailed for each project to interested parties upon request. Interested parties shall contact the Commission office to be placed on the mailing list. Small wetland impacts include all projects which fill less than 0.1 acre of wetland; and all those projects which will fill less than 0.25 acres of wetland, and result from a private road fill or the construction or expansion of a single family dwelling unit or farm building when the project cannot be modified so as to avoid the fill. Wetland Banking BWSR is responsible for the establishment and management of a state wetland bank which would make wetland credits available to landowners who cannot avoid wetland impacts and where mitigation areas are not available. The Commission will consider -anticipation in the state wetland bank once such a bank has been established and LGUs re notified. LGU Arlministmtive Costs LGU services provided by the Commission or its staff in administering the Wetland Conservation Act shall be paid for by member cities. Costs and expenses incurred by the Commission will be billed directly to the member city (member cities are responsible for collecting fees from the applicant for these services). An escrow amount of$1,500 shall be • deposited with the original application by the member city. The Commission and its staff will advise the member city if expenses and costs are expected to exceed the original deposit filed with the application. Services will not be performed beyond monies on deposit unless the member city has agreed in writing to be responsible for the cost of these services. The Commission and its staff will itemize all time, services; and expenses incurred in providing services to a member city or to an applicant within a member city in administering the Wetland Conservation Act. The city or.the applicant making the escrow deposit shall, upon request, be furnished a copy of said itemized charges. Any balance remaining in the escrow account upon completion of all services necessary to administer the act for that application will be returned to the member city by the Commission after all claims for time, services, expenses, or charges have been paid. Security for Approved Wetland Replacement Projects In all cases where the Commission acts as the LGU and in cases where the Commission assists a member city and assumes some responsibility for the successful completion of wetland replacement plans and associated monitoring activities, the following deposits shall be required: 1. The applicant shall deposit a cash escrow with the member city in an amount determined by the Commission to cover all estimated engineering, legal, and administrative costs associated with approved wetland replacement projects. The Commission will be reimbursed by the member city from the escrow account for actual expenditures. If this account is expended or if staff determines that the amounts being held in escrow are not sufficient to cover estimated expenditures, the applicant shall deposit such additional funds necessary to cover the estimated -4- SCWMC Wetland Management Policy costs. Failure to make the required deposits will result in the Commission ordering the applicant to cease and desist from any further work or development, and i2. The applicant shall provide a performance bond or an irrevocable letter of credit with the member city in an amount determined by the Commission to cover 150% of the estimated wetland replacement costs to guarantee the successful completion of the wetland replacement in complying with the Wetland Conservation Act. Upon completion of all or part of the required work, the Commission upon recommendation by its engineer, may authorize the member city to reduce the amount of the bond or irrevocable letter of credit. Upon completion of the wetland replacement activities, a five year monitoring program is required by law to ensure that replacement wetlands achieve the goal of replacing lost wetlands. The applicant's performance bond or its irrevocable letter of credit on deposit with the member city shall be continued as provided in an amount determined by the Commission in carrying out the responsibilities of the member city and Commission under the Wetland Conservation Act and rules and regulations promulgated or adopted by federal, state, county, or city governments or by this Commission. It is the intention of this Commission that the applicant proceed with replacing wetlands in accordance with approved plans and meet all the required monitoring standards. The Commission shall follow up with the applicant and if the applicant fails to provide any or all of the necessary monitoring reports or fails to construct the replacement wetland as approved or take corrective measures to ensure successful completion to of the wetland replacement plan, the Commission or any of its members directed by the Commission shall make said corrections, and the performance bond or the irrevocable letter of credit • shall provide all the funds necessary to comply with the applicable governmental regulations. -5-