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HomeMy WebLinkAbout6A - 1994 Prior Lake/Spring Lake Improvement Projects Res. 93-87 AGENDA #: PREPARED BY: SUBJECT: DATE: INTRODUCTION: STAFF AGENDA REPORT 6A JOEL RUTHERFORD, WATER RESOURCES COORDINATOR CONSIDER SUPPORTING AND SPONSORING THE PRIOR - SPRING LAKES IMPROVEMENT PROJECT AND CONSIDER ADOPTING RESOLUTION 93-87 OCTOBER 18, 1993 The purpose of this Agenda item is to consider sponsorship of the Prior - Spring Lakes Improvement Project, which is a six year work plan being proposed by the Prior Lake/Spring Lake Watershed District. This project includes an implementation plan which includes improvements designed to improve water quality in the lakes, wetlands and other water bodies of the watershed. As part of this sponsorship, the City would support the Watershed in their application for a Clean Water Partnership Phase II - Project Implementation Grant. This Grant, if awarded, would provide approximately 50% cost share for most of the projects. The Watershed has indicated the application deadline for this grant is late October of this year. If the Council elects to be a sponsor of this project, the City would be eligible for matching funds to help pay for storm water capital improvement projects implemented over the next six years. The Council is being asked to adopt the attached resolution which authorizes the Watershed District Manager to be the project representative. The resolution also indicates the estimated cost of the entire project, as well as the estimated costs to the City if all the projects are completed. If a grant is awarded, the Council will be asked over a six-year period to consider the projects included in the plan for which the City is the "Lead Local Agency". This consideration would be done during the normal budget process. If the Council elects to budget money for these future projects, and the projects are implemented, the City would receive the funds awarded as part of the grant. -1- 4629 Dakota St. S.E., Prior Lake, Minnesota 55372 / Ph. (612) 447-4230 / Fax (612) 447-4245 AN EQUAL OPPORTUNITY EMPWYER BACKGROUND: DISCUSSION: If a grant is not awarded, the City could either choose to look at alternative funding sources, or reject projects for which funding Is not available. Through the EPA's Clean Lakes Program, the Prior Lake/Spring Lake Watershed District has completed a Implementation Plan for the Diagnostic/Feasibility Study of Prior and Spring Lakes. This implementation plan includes several projects, all of which have the goal of improving water quality in the watershed. Several of the projects are capital improvement projects which would benefit Upper and Lower Prior Lakes by helping to reduce phosphorus levels and other nutrients which have caused degradation of the lake waters. One project will be used to inventory water quality basins in the watershed. Other projects included in the plan are education projects which will show residents how they can help reduce the amount of nutrients getting into our water bodies. The funding for this implementation plan would come from various agencies and from a grant, if awarded. The watershed district is asking the city to support and help fund this program. The implementation plan proposed by the watershed district includes many projects. The complete study, which is about 2 inches thick, is available for review at City Hall. However, an Executive Summary for this study has been included with this report. The Diagnostic/Feasibility study was completed by Montgomery Watson, the consulting firm hired by the Watershed District. To be eligible for a Clean Water Partnership Phase II - Project Implementation Grant, a study was required which included an implementation plan. The Watershed District and City staff have worked together to include projects in this plan which are part of the City's preliminary stormwater capital improvement program. By receiving grant funds, these projects could be partially supported with grant money. It should be made clear that the resolution, proposal, and any commitment by the City, at this point, is contingent on a grant being awarded. The Watershed District has committed to a project whether a grant is awarded or not. Their project list, however would most likely be scaled back without the financial support of a grant. The City has also made a commitment (through the establishment of a storm water utility fee) to complete projects designed to improve water quality. The purpose of the proposal submitted by the watershed is to apply for a grant to help fund the projects already determined to be important. If the grant is not awarded, it is understood a different approach is necessary to complete the projects proposed. -2- An award of a grant would be based on the premise that the completed plan would improve water quality to a degree as indicated in the study. However, there will be flexibility in the future as to how those improvements in water quality will be obtained. The project list and schedule, as included in the application, will be re-evaluated, and possibly revised, each year. The council will be given an opportunity to alter some of the projects if higher priority projects are identified in the future. A summary of projects the City is being asked to help sponsor is listed below. Attached to this report is Exhibit 1 which summarizes the project costs. Slgnage and Street Sweeping Coordination is part of the Public Information/Education program. Because the City already has a street sweeping program, the main expenditures for this item would be to stencil certain catch basin areas with "Drains to Prior Lake", or something similar, to alert residents that anything entering the storm sewer, including grass clippings, etc., will end up in the lake. The cost for this project is from in-kind service of 82 hours. Water Quality Basin 1 Improvement is the impoundment structure proposed at Holly Circle and Cates Street. The City received a grant from the Minnesota Board of Water and Soil Resources (BWSR) for half the cost of this project, up to a certain amount. However, when the bids were 2 1/2 times the engineer's estimate, the project was canceled. If the PUSLWD receives their grant, and the City receives an extension for the BWSR grant, it may be possible to construct the structure with almost 100% grant money. It may require reducing the scope of the project slightly to lower the construction costs, an option already suggested as a way to get the project completed. Water Quality Basin 4 Improvement is to convert a pond near Beach Street from a dry pond to a wet pond. This project was included in the plan with the assumption that a valve was never installed, and therefore the pond would remain dry if not improved. However, a valve was installed, so this project may involve improvement by enlarging the capacity of the pond, to provide additional storage of sediment, or a different project may be substituted later. A Water Quality Basin Inventory has been scheduled to be included in the Comprehensive Storm Sewer plan which should be completed this winter. The lake-wide Aquatic Macrophyte Management Plan is necessary to facilitate a long-term comprehensive aquatic macrophyte management plan, including the control of Eurasian Water Milfoil. -3- An Aquascaplng plan is a promotion to educate lake shore owners of the benefits proper shoreline landscaping can have on water quality in the lakes. Monitoring of Spring and Prior Lakes has been proposed for 1996 and 1999, to determine the effectiveness of the projects in the implementation plan. A Ferric Chloride System is proposed for installation along County Ditch 13 at the outlet of an existing sediment basin. The precipitant, iron in this case, causes flocculation, which precipitates phosphorus and solids to the sediments. By increasing the rate of precipitation of soluble phosphorus, less is available for algae growth in the lake. In summary, the request for sponsorship by the PUSLWD is a very reasonable proposal, which allows the city and watershed district an opportunity to work together on many issues both are committed to. The City has already begun planning for many of the projects included in the proposed implementation plan. The PUSLWD has taken a step further, however, by rating the projects, and including them in a comprehensive study, with projected costs and benefits. If the city commits to being a sponsor, any grants that ~ be awarded will help the city pay for some projects originally assumed to be paid entirely out of the city's budget. If a grant is not awarded, a different approach would be necessary. The City will be the lead local agency, responsible for completing a few of the projects listed above. In those cases, if the city chose to construct a project other than those indicated in the proposal, that would be an option the grant would allow. However, to receive the grant it would need to be shown that the benefits of the new project are the same or better than the benefits from the project rejected. The resolution included in this report will support the Watershed's Project, and agree to identify the Executive Director of the Watershed District as the Project representative. It commits financial support, in an amount not to exceed $74,134, and staff labor, not to exceed 82 hours. These dollars would come from the storm water utility fee, spread out over the next 6 years. Again, these commitments are all contingent on receiving grant funds. The Lake Advisory Committee was given a presentation by Paul Nelson of Montgomery Watson at their meeting on September 15, 1993. They unanimously support the proposed sponsorship, and staff labor as outlined in the Watershed District's proposal. -4- BUDGET IMPACT: Over the six year duration of the project, funds from the Storm Water utility fee, which in 1993 will generate approximately $103,000, would be used for this project. If fully implemented the total cost to the City would be about $76,104 or $12,700 per year. Many of these programs and projects were proposed to be implemented and paid for through the funds generated by the storm water utility fee. Upon completion of the City's local comprehensive Storm Water Management Plan, a thorough study on the programs and funding alternatives will be presented to the Council. ALTERNATIVES: The alternatives are as follows: 1. Adopt Resolution 93-87 2. Do not adopt Resolution 93-87 RECOMMENDATION: Adopt Resolution 93-87 ACTION REQUIRED: The action required is for the City Council to adopt Resolution 93-87. LACAG1.WRT -5- Exhibit 1 . Summ~ of Costs PROJECT CITY'S TOTAL PROJECT OTHER AGENCIES DESCRIPTION COST COST PARTICIPATING SignagelStreet $1,970.00 $1,970.00 Sweeping Coordination Other Public 0.00 $64,200.00 Scott County En. InformationlEducation PUSLWD Water Quality Basin $30,000.00 $60,000.00 Grant 1 Improvement Water Quality Basin $3,885.00 $7,770.00 Grant 4 Improvement Water Quality Basin $4,475.00 $17,900.00 PUSLWD Inventory Grant Aquatic Macrophyte $3,804.00 $25,220.00 PUSLWD Management Plan MnDNR Grant Aquascaping $1,250.00 $5,000.00 PUSLWD Grant Monitoring $8,520.00 $68,170.00 PUSLWD Grant Ferric Chloride $0.00 $38,200.00 PUSLWD System (installation) Grant Ferric Chloride $22,200.00 $44,400.00 PUSLWD System (0 & M for 6 years) Fertilizer $0.00 $28,000.00 Scott County Ext. Management Incentives Grant Conservation Tillage $0.00 $28,000.00 Scott County Ext. Equipment Grant Aeration System $0.00 $212,190.00 PUSLWD Grant Wetland Restorations $0.00 $117,690.00 PUSLWD Grant Other Projects $0.00 $55,360.00 PUSLWD Scott County En. Scott County SWCD Grant TOTAL $76,104.00 $774,070.00 -6- RESOLUTION 93-87 RESOLUTION IDENTIFYING PROJECf REPRESENTATIVE AND AUTHORIZING A PHASE II APPUCATION BE IT RESOLVED BY THE CITY COUNCIL OF PRIOR LAKE, MINNESOTA, that the Oty of Prior Lake hereby designates William Dilks, Executive Director, Prior Lake-Spring Lake Watershed District as the Project Representative for the Prior-Sprin, Lakes Improvement Project and proposed Clean Water Partnership Phase II - Project Implementation Grant The Project Representative shall have the authority to represent the City of Prior Lake in all matters that do not specifically require action by the Prior-Spring Lakes Improvement Project sponsors. The Minnesota Pollution Control Agency (MPCA) shall direct Clean Water Parttlership Application correspondence to the Project Representative and shall consider correspondence from and actions taken by the Project Representative to be that of the Prior-Spring Lakes Improvement Project sponsors, including the City of Prior Lake. BE IT FURTHER RESOLVED by the City of Prior Lake that the Project Representative designated above is hereby authorized to submit to the MPCA a Clean Water Partnership Phase II - Project Implementation Grant Application for the Prior-Spring Lakes Improvement Project. BE IT FURTHER RESOLVED by the City of Prior Lake that the total project cost of the Prior-Spring Lakes Improvement Project is expected to be $774,070. In addition, the City of Prior Lake shall provide up to $51,934 in grant matching funds, and other costs. for the six year duration of the project The City of Prior Lake also agrees to provide up to 82 hours of staff labor valued at $1,970, and 50%. up to $3,700 per year, of the annual operations and maintenance cost of the ferric chloride addition system for the six year project duration. The total cost to the City for the six year project would be a maximum of $76,104. BE IT FURTHER RESOLVED by the City of Prior Lake that on a yearly basis, the projects included in the proposed plan for which the City is the "Lead Local agency", will be evaluated to determine if the project will be delayed or if alternative projects should be implemented. Any alternative projects would be required to meet or exceed the benefits obtained from the projects included in the original plan. Passed and adopted this 18.th day or October, 1993. YES NO Andren Fitzgerald Kedrowski Scott White Andren Fitzgerald Kedrowski Scott White Frank Boyles City Manager { Seal } -7- 4629 Dakota St. S.E., Prior Lake, Minnesota 55372 / Ph. (612) 4474230 / Fax (612) 447-4245 AN EQUAL OPPORTUNITY EMPLDYER ( . . EXECUTIVE SUMMARY This report presents the results and recommended Implementation Plan (or the DiaenosticIFeasibility Study on Prior and Sprinl Lakes. The project was a joint effort and was funded by the Prior LakelSprinl Lake Watershed District CPSlSLWD) and EPA throuch a 5&J, cost share in the Clean Lakes PrOI1'am. The State o( Minnesota's Pollution Control ~eney (PCA) provided technical review and project man8iement. DIAGNOSTIC STUDY The DialDostic Study included a 12-month water quality monitorinl prOl1'am and subsequent data and land use assessments which characterized the sources o( water quality problems on the lakes. The Feasibility Study evaluates the various alternatives (or water quality improvement and develops the Implementation Plan (or the project. Spring, Upper Prior, and Lower Prior Lakes are important recreational resources. Sprinl Lake is a (ocal point for the planned Regional Park which will include a swimminl beach. Upper and Lower Prior Lakes are connected, have public access and swimming beaches. Algal blooms are the primary problems restricting desired uses of Spring and Upper Prior Lakes. These blooms are excessive during the growing season with chlorophyll-A concentrations averaging 45 ~ and 35 J1g/l for Spring and Upper Prior Lakes, respectively. Blooms of this magnitude place both lakes in the worst 33% of lakes in the Central Hardwoods Region. Lower Prior Lake has much better water quality and is in the best 33% of lakes in the Central Hardwoods Region. Primary productivity (algal growth) in Upper Prior and Lower Prior Lakes is clearly limited by the availability of phosphorus. Primary productivity in Spring Lake is not always phosphorus-limited. This is due to extremely high phosphorus concentrations in Spring Lake, makinl it overly abundant. Even thouch Sprinl Lake is not always phosphorus- limited, phosphorus is still the primary pollutant targeted for reductions (or several reasons: . Phosphorus levels can be reduced to the point where it again'becomes limiting. . It is generally easier to reduce phosphorus than other nutrients. ES-l ( · The aleal apedes dominatinr SPrinl Lake are blue-rreens which caD fix their own nitroeen. . Reducin&, nitro&,en without equal or creater reduction. of phosphorus could live a rreater competitive advantare to blue-rreen alese. . Primary produc:tivity in Upper Prior Lake, which receives 55% of ita phosphorus budget from Sp~ Lake, is clearly phosphorus-limited. The direct watershed area to Spring Lake encompass88 13,250 acres. This lar&,e watershed lives Sprin&, Lake a relatively short hydraulic residence time of 1.3 years. The western portion of the direct watershed to Spring Lake is dominated by 8.&'riculturalland uses. These uses consist primarily of row crops. Approximately 23% of the direct watershed to Sprini Lake is hiihly erodible soils. Streams from these watersheds contribute 41% of the total phosphorus load to Spring Lake. Because of the large amount of highly erodible land and the hieh phosphorus loading to Spring Lake, these subwatersheds were classified as hiih priority for implementation of qricultural Best MaDaiement Practices (BMPs). Internal phosphorus loading is sienificant in Spring Lake. Internal loading is estimated to contnbute 33% of the total phosphorus load in Spring Lake. Internal loadin&, causes the buildup of soluble reactive phosphorus within Spring Lake. This form of phosphorus is the most readily available form for algal uptake. Approximately 60% of the phosphorus in Sprini Lake is soluble. Manqement of soluble phosphorus and internal loading in Spring Lake will be important for improving Upper Prior Lake as well as Spring Lake. Upper Prior Lake has a relatively small lake volume. This lives the lake a short hydraulic residence time of 0.2 years and means that controlling external phosphorus sources are particularly important for improving the lake. Prior Lake receives 55% of its phosphorus from Spring Lake. Thirty-five percent of the remaining phosphorus load comes from the direct drainage area to Upper Prior Lake. Much of the shoreline is hiehly developed. Lawn maintenance to the water's edge is a common practice. In addition, city areas south of the .lake are heavily developed. Few opportunities exist for stormwater system retrofits or for new stormwater .quality basins. Public education will be important for urban areas surrounding Upper Prior Lake. ES-2 \ The water quality of Lower Prior Lake i. fairly cood. However, there are .icniticant development pt'e8sures, particularly alone the north shore of the lake. Wise development will be important in maint.Ainine the quality of Lower Prior Lake. FEASmILITY STUDY In the Feasibility Study, a number of alternatives were evaluated to reach phosphorus concentration eoals. These alternatives ranee trom administrative alternatives such as fertilizer management education programs to structural alternatives such as wetland restoration. Each option was evaluated for potential water quality benefits, estimated initial and long-term (operation and maintenance) costs, and technical feasibility. The most technically sound and cost-eft"ective options were incorporated into the Implementation Plan for improving the lakes. Special consideration was given to alternatives that address problems and reduce pollutant loadings at their source, and to alternatives that have the potential to reduce runoff as well as phosphorus. The Feasibility Study also identifies numerous existing water qualit1 initiatives by the PUSL WD and other local agencies. The Implementation Plan was designed to complement these exis~ initiatives, particularly land development regulations. Parts of the PUSL WD are currently experiencing rapid urban development. Areas without sewer are being developed as single family lO-acre lots. The Implementation Plan improves regulation of this transition through revised wet pond design criteria, by developing methods for ensuring maintenance of water quality facilities, and by public education efforts. The final plan includes the following elements: . A public information/education program which will focus on fertilizer management, yard waste management, septic system maintenance, enlisting public support, and improving non-point source pollution prevention practices by local landowners. . Amendments to the District's 509 Plan including revisions to water quality pond design criteria, clarificiltion of responsibilities for m~taining storm water facilities, and amendments to protect landlocked basins. ES-3 t . A fertilizer wnAnAlement incentive proeram to encoUl8le .,ncultural operaton in the priority watersheds to utilize soil tests and manare aericultural nutrients that will achieve profitable crop production and reduce nutrient runoff. . Promotion of no-till farminc throu.ch the purchase of a no-till drill for use by farmers in the priority watershed. . Promotion of aquascapinr as a means of establishing residential shoreline buffers. . Modifications to existing storm water basins to improve phosphorus sedimentation and reduce phosphorus loadinr to the lakes. . The restoration of four priority wetland areas to reduce the phosphorus load to Spring Lake, provide flood storage, and wildlife habitat. . A feme chloride chemical feed system to reduce the inflow of dissolved phosphorus from County Ditch 13 to Sp~ Lake. . Aeration of Sp~ Lake to reduce internal cyclinC of phosphorus. . Development of lake-wide aquatic macrophyte management plans to facilitate long-term comprehensive aquatic macrophyte management following treatment of Eurasian water milfoil. . Improvements to a northern pike spawning area on Lower Prior Lake. The estimated cost of implementing the plan over the six-year project duration is $774,070. Implementation of the plan will reduce phosphorus loading to Spring Lake, Upper Prior Lake, and Lower Prior Lake by 40%, 30%. and 20%, respectively. These reductions will significantly reduce the frequency and severity of aleal blooms. A reduction in algal blooms . will also decrease the volume of OTganiC matter which contributes to sediment oxygen demand. Reducing algal blooms will also increase water clarity. The improved conditions will be sufficient to change Sprin, Lake from non-supportinr to partially supporting swimming. Water clarity in Upper Prior Lake will increase by an estimated 0.8 feet. ES-4 \ One consequence or improvm, water clarity may be an increase in the lI'owth or aquatic macrophytes (weeds). lnC1'8ased li~ht penetration may allow weed Jrowth into deeper waters. This should be viewed as improvin~ the biolo,ical health and diversity of the lakes. This chan~e will also be addressed as part of the aquatic macrophyte ftlAn411lement plans. ES-5