Comfort Lake Forest Lake Watershed District



Floodplain, Drainage Management/Stormwater management, and Climate ResiliencySummary of Existing DataFEMA Maps (limited coverage for waterways and lakes in District)DNR Lake Finder Water LevelsCLFLWD Water Level and Stream Monitoring DataOld XP-SWMM Model: District’s Hydraulic Capacity and Model Calibration Report (SRF, 2005)Updated PC-SWMM models (only portions of the District have been modeled so far)Reports and Planning - Level DocumentsEngineer’s Report: Sunrise River Water Quality and Flowage Project (EOR, 2012)This project is a water quality and quantity improvement effort located within the drainage area to a branch of the Sunrise River (also known as Judicial Ditch 1) between the City of Forest Lake and Comfort Lake. The primary project goal was to reduce nutrient and sediment loading to Comfort Lake from the Sunrise River drainage area and secondarily to reduce seasonal flooding along portions of this branch of the Sunrise River upstream of Comfort Lake. The project identified 6 projects to achieve these goals:Bixby Park Water Quality Improvement Wetland - completedWyoming Wetland Enhancement (Banta/Ducharme & District Tax Forfeit) – in progressShallow Pond RestorationMcCullough Property Future Water Quality ImprovementForest Lake Urban Area RetrofitsCarp ManagementCLFLWD Ordinance Comparison Memo (EOR, 2015) and update (EOR, 2016)WJD-6 Diagnostic Study (2018)WJD-6 2019 Feasibility Study (2020)Washington County 2040 Comprehensive Plan, Chapter 9 – Resilience and SustainabilityThis chapter of the Comprehensive Plan provides clarification on what resiliency, sustainability and social equity means to the county. While elements that address resiliency and sustainability are included throughout the Comprehensive Plan, this chapter recognizes four key areas not included in other plan elements:Hazard MitigationHealthy CommunitiesEnergySolid Waste ManagementSummary of Data LayersAltered Water CoursesNLCD 2006 ImperviousnessPublic Waters InventoryLake Management District:Bone LMDLittle Comfort LMDForest LMDComfort LMDPrioritization Criteria????Development DemandsAreas of Agriculture, slowly converting to Large Lot ResidentialCity of Scandia planning to expand “neighborhood residential” northwest of Scandia. This is a multi-use zoning intended to preserve agricultural land and with flexible land-use including incentives for conservation/cluster design to protect key natural resources.Heath Avenue drainage area has a higher density of single family homes. The rest of the drainage area is primarily agricultural or large lot SFH.Heavily developed shoreline around the entire lake. Some commercial areas in the downtown Forest Lake area. Watershed consists of mixture of residential densities with some remaining agriculture and a lot of wetlands.Medium-density housing expected in the SW shoreline of Forest Lake.Large conservancy areas south of Forest Lake and North of Forest Lake where important wetlands and wildlife habitat are located. These areas are protected from expansion or development.Significant commercial and residential development has already occurred in Forest Lake. More development is coming in Wyoming. There is a need for regional treatment for some of the urban areas looking to redevelop. Conversion of HWY 8, I35 intersection from conservancy district to parks and recreationHighway-8 expansion.MIDS/Ordinance Comparison??Scandia ? Chapter 3 of the Development Code has sections dedicated to Minimum Design Standards, Stormwater Management, and Erosion Control. They are clear and organized. ? Chapter 2 also has Development Standards highlighting environmental regulations, stormwater management, land alteration, and woodland preservation. ? Subdivision section of code includes provisions that appear to satisfy the WD requirements. [Ch. 3; 14.1; 1] Chisago Township? The Chisago County ordinances are generally short and sparse compared to the MIDS standards. ? Very little is mentioned regarding stormwater and erosion control. ? There does not seem to be any Watershed District requirements stated, but the local watershed agencies may be consulted during the platting review process. [Subdivision, 4.01, E] Forest Lake ? A dedicated Stormwater Management Ordinance exists (Chapter 151) and clearly defines standards and practices. ? The Stormwater Management section also contains Erosion Control Measures. ? The ordinance and erosion control measures appear to satisfy the WD requirements. [151.08, P] Wyoming? The Surface water Management Section is brief but cross references external material. ? Specific stormwater management measures are scattered throughout the Subdivision and Zoning sections. ? The ordinance appears to satisfy the WD requirements. [Sec. 32-94, 2] Chisago Township? The Chisago County ordinances are generally short and sparse compared to the MIDS standards. ? Very little is mentioned regarding stormwater and erosion control. ? There does not seem to be any Watershed District requirements stated, but the local watershed agencies may be consulted during the platting review process. [Subdivision, 4.01, E] Public/ Private Ditch System (laterals are all private)Some private agricultural ditches. Some private agricultural ditches.Washington County WJD-6 System. WJD-6 is related to recent boundary change. RCWD had been the LGU until 1-2 years ago. CLFLWD now the Ditch Authority. Only public ditch system in the District. Not actively farming along WJD-6 anymore. More large-lot residential.Sunrise River –formally JD-1. This system is now a public watercourse.Altered Watercourses & Public WatercoursesSecond-most identifiedAll altered or no definable channelBBSLC TributaryJuly Ave TributaryPublic watercourse from Little Comfort to School to Birch LakesFewest, given sizeAll altered or no defineable channelMost identified altered channelsJD2Sunrise RDitch lateralsFlooding concerns/ Floodplain opportunitiesPast Beaver activity downstream of Moody Lake resulted in resident concerns on Moody Lake a couple years ago. Bone Lake has a flashy response to storms sometimes resulting in concerns from landowners.Some wet rear yards adjacent to the wetlands just downstream of Bone Lake have resulted in some land owner calls.Forest Lake is large compared to its watershed and doesn’t bounce very much. Recommendation for floodplain acquisition along WJD-6 to convert ditch to a natural system.Some water level concerns along the old JD-1 system. The ditch was abandoned and the County obtained some easements. District owns some low lying tax forfeited parcels. A ton of floodplain and wetlands along the stream corridor for SunriseLandlocked System (lakes landlocked for the back-to-back 100- year, 24-hour event)Several small land locked areas on the eastern side of the watershed. One containing Second and First lakes and one containing a small unnamed resource near Scandia Trail N.Landlocked lakes (for the back-to-back 100-year, 24-hr event): Nielson, Sea, and FirstArea is pretty well drained and tight soils, no land locked areas identified beyond those in the 2005 study.Landlocked lakes: Sylvan, Elwell, and ClearArea is pretty well drained and tight soils, no land locked areas identified beyond those in the 2005 study.Modeling (See figure below)Updated PC-SWMM model for Bone Lake Watershed created for Bone Lake Diagnostic Study. PCSWMM model for this LMD is proposed to begin in 2020.Update PC-SWMM model for the Heath Avenue Drainage Area. This is proposed to begin in 2021.Updated PC-SWMM modeling for the WJD-6 Subwateshed completed as part of the WJD-6 Diagnostic and Feasibility Studies. PC-SWMM update for this LMD is proposed to begin in 2022.Updated PC-SWMM modeling in process, began in 2019. City of Forest Lake is working on more detailed catch basin level modeling for some of the downtown and Broadway areas.Monitoring DataLong term records for water levels on Bone Lake are available going back to 1965 (no data 1969, 1983-1988, and 1993). Moody Lake has complete data starting in 2013.Water levels for little Comfort Lake are available from 1985-2004. Note - water levels are assumed to be the same as Comfort Lake – Lake gage has been installed in Little Comfort Lake in 2020 to check this assumption. Long term records for water levels on Forest Lake are available going back to 1965 (no data 1982-1988). Shields Lake has data going back to 1991 (no data 1993-1995, and 2011-2012), and Keewahtin Lake has data going back to 1990.Long term records for water levels on Comfort Lake are available going back to 1952 (no data 1953-1964, and 1966-1968). Climate ResiliencyRecent wet weather patterns have resulted in increased saturation of soils, higher wetland levels, and higher GW levels. Changing weather patterns may exacerbate patterns. 2019 was the second wettest year on record in the City of Forest Lake. Statewide there are climate trends towards wetter conditions and more frequent and larger events. Existing GoalsPrevent encroachment of the 100-year floodplain to conserve water storage capacity and maintain floodplain hydrology.Recommended: Ensure no net loss of flood storage capability within the watershed Action 1: Easements or acquisition of parcels in the floodplainHigh – where? upstream of Bone Lake Outlet wetlandLow – minimal opportunitiesHigh – where? WJD-6High – where? Sunrise River systemLimit flood damage to infrastructure and natural resources. – Recommended revision: Assess the potential for flooding properties and natural resources when evaluating land management activities (through the District’s permitting program) Action 1: Model really extreme event scenarios in the updated PC-SWMM models to identify “at-risk” parcelsAction 2: Have long-term water level monitoring in wetlands that have rising water levels and landlocked lakesHigh – where? reports of flooding concerns in Moody and Bone Lake, 3 landlocked lakes, 2 landlocked basinsHigh – where? reports of flooding concerns in Bone Lake Outlet wetlandHigh – where? Hayward Avenue & increasing development, 3 landlocked lakesMedium – where? Around I35 and Hwy 8, Sunrise River systemStormwater Management Goals?Recommended: Ensure no net increase in runoff rate, volume and pollutant loading from new development and redevelopment (Via District’s permitting program)Medium - expected new development and redevelopment near ScandiaLowHigh – expected new development and redevelopment around Forest LakeHigh – expected new development and redevelopment around HWY 8 and Comfort Lake, City of Forest Lake, and Sunrise RiverClimate Resiliency Goal(s)Recommended: Develop a better understanding of climate change, its impacts to the District’s land and water resources, and adaptive strategies to make the District and its communities more resilientMaintain and improve community preparedness and emergency response capacity to ensure public health and safety (Washington County)Medium – where? City of ScandiaHigh – where? Bone Lake Outlet WetlandHigh – where? City of Forest LakeHigh – where? Comfort Lake/City of Wyoming ................
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