North Fork Crow River Watershed Groundwater Restoration and Protection Strategies Report

The North Fork Crow River Watershed (NFCRW) (Hydrologic Unit Code [HUC] 07010204) spans over 949,107 acres in central Minnesota. Parts of Pope, Kandiyohi, Stearns, Meeker, Wright, Hennepin, Carver, and McLeod counties are in the watershed. Groundwater accounts for over 94 percent of the water appropriated and 100 percent of the drinking water in the NFCRW. The watershed is home to a variety of natural resources that rely on groundwater (groundwater dependent features). There are many land uses and activities in the NFCRW that impact the availability and quality of groundwater and drinking water resources. Five State of Minnesota agencies collaborated to develop a Groundwater Restoration and Protection Strategies (GRAPS) report for the NFCRW. This report is designed to help prioritize and target local efforts to restore and protect groundwater resources in the NFCRW. Representatives from BWSR, MDA, MDH, DNR, and MPCA researched, compiled existing state data, and developed maps to establish a baseline understanding of groundwater conditions and associated resource management concerns for the NFCRW. The team developed strategies and supporting actions that can be applied at a county, subwatershed, or watershed level to help restore and protect groundwater. Due to the differences in the geology and land use practices throughout the watershed, the types of groundwater issues and concerns vary. The NFCRW can be divided into three main regions based on geology and general land use practices: ▪ The western region is underlain by glacial sediments and crystalline rock. The majority of the groundwater is available from layers of glacial sand. The region has a low population density and has extensive irrigated row crop agriculture. A large portion of the region has high pollution sensitivity, meaning there is a higher risk for groundwater to be polluted by contaminants from the ground surface. Other parts of the region have low pollution sensitivity (the contamination risk is lower). This region of the watershed overlaps with the Bonanza Valley Groundwater Management Area, a region identified by the DNR as being at risk for groundwater overuse. ▪ The central region is underlain by glacial sediments and Cretaceous sandstone and shale. Most groundwater is derived from the glacial sands. In general, the population density in this region increases as you move from the west to the east. The region has some row crop agriculture and a few areas with high and medium pollution sensitivity, with the remainder having a low pollution sensitivity. ▪ The eastern region is underlain by glacial sediments and Paleozoic sandstone and shale; glacial sands and Paleozoic sandstones constitute the dominant aquifers. This region has the highest population density of the three regions, since it includes parts of the western suburbs of Minneapolis. There is little row crop production in this region. Most of the region has low pollution sensitivity with a few areas of medium or high pollution sensitivity. Groundwater and drinking water quality concerns in the watershed include: ▪ Nitrate contamination in wells primarily located in areas with high pollution sensitivity. ▪ Arsenic has been detected in groundwater in a variety of locations throughout the watershed. ▪ Pesticides have been detected in groundwater in the western region of the watershed. ▪ Animal feedlots, stormwater infiltration practices, and subsurface sewage treatment systems (SSTS) are located throughout the watershed and can lead to groundwater contamination if improperly installed or maintained. ▪ Active and leaky tank sites (referred to as contaminated sites) are located throughout the watershed, with the most in the western and eastern regions. ▪ Closed landfills with known groundwater contamination plumes are scattered throughout the watershed, with the greatest concentration in the central region. Groundwater quantity concerns in the watershed occur where groundwater withdrawals outpace groundwater recharge and where withdrawals can adversely affect groundwater dependent features. There is a record of declining water levels primarily in the western region. A variety of natural resources, such as fens and trout streams, depend on groundwater to sustain their characteristics. These groundwater dependent features can be negatively impacted by changes in groundwater quantity or quality. While there are a variety of groundwater quantity and quality issues and concerns, this report identifies the following key strategies to address the issues and concerns: ▪ Conservation Easements: Maintain and expand the amount of land protected from being converted to high intensity uses, such as row crop agriculture. ▪ Contaminant Planning and Management: Use land use planning, ordinances, and collaboration with state regulatory agencies to protect groundwater and drinking water supplies from contaminant releases. ▪ Cropland Management: Encourage the implementation of voluntary practices to manage resource concerns while minimizing environmental loss. ▪ Education and Outreach: Educate landowners, private well users, and other stakeholders about how their actions affect groundwater and what they can do to conserve, restore, and protect groundwater. ▪ Integrated Pest Management: Implement a pest management approach that incorporates the many aspects of plant health care/crop protection in ways that mitigate harmful environmental impacts and protect human health. ▪ Irrigation Water Management: Control the volume, frequency, and application rate of irrigation water to sustain groundwater. ▪ Land Use Planning and Management: Use city or county government planning and regulations along with land management goals that implement best management practices (BMP), conserve water, and educate stakeholders to protect groundwater levels, quality, and contributions to groundwater dependent features. ▪ Nutrient Management: Assure that application of crop fertilizer or manure uses the right source, right rate, right time, and right place. ▪ Subsurface Sewage Treatment System (SSTS) Management: Monitor, maintain, and/or upgrade SSTS to assure proper operation and treatment. The GRAPS report proposes specific actions individuals, local government, and partners can take within each of the nine key strategies. The report also identifies which counties and subwatersheds (HUC-10) should be prioritized for each action. The NFCRW GRAPS report should be used in conjunction with the North Fork Crow Watershed Restoration and Protection Strategy Report (https://www.pca.state.mn.us/sites/default/files/wq-ws4-06a.pdf) report to develop the local water management plan. The WRAPS report informs how to restore and protect surface water, and the GRAPS report informs how to restore and protect groundwater in the NFCRW.