2017 Spencer Comprehensive Land Use Plan

Spencer, Iowa  2017  Comprehensive Plan

housing, recreation, commercial, and other kinds of development should take account of the suitability and limitations of soils for such uses. Soil surveys describe soil properties in detail and can help planners establish general patterns of soil suitability and limitations for various land uses. AQUIFERS AND GROUNDWATER In the Iowa Department of Natural Resources’ book Iowa’s Groundwater Basics - A Geological Guide to the occurrence, use & vulnerability of Iowa’s aquifers, the City of Spencer is located within the Northwest Iowa Hydrogeologic Region. Groundwater sources in northwest Iowa can generally be characterized as “fair” in terms of availability and quality. There are fewer options in northwest Iowa in comparison to those located in central or northeast Iowa. Groundwater resources in Spencer are typically found through two major sources; surficial aquifers (shallow aquifers) including alluvial aquifers and the Dakota and Jordan Aquifer (deep aquifer). The well sources in Clay County are primarily dependent upon the Dakota sandstone aquifer. The wells in the region average 700+ feet in depth and have the lowest levels of nitrates of any of the other hydrogeologic regions in the state. In general, this region proved to have the overall lowest level of contamination when considering all forms of water contaminants.

Figure 7 - Map of Dakota Aquifer in Iowa (left) and the Jordan Aquifer in Iowa (right)

Spencer

Spencer

STORM WATER MANAGEMENT The EPA describes storm water runoff as “rain or snow melt that flows off the land, from streets, roof tops, and lawns. The runoff carries sediment and contaminants with it to a surface water body or infiltrates through the soil to groundwater.” During storms and heavy periods of rainfall, storm water travels across impervious surfaces collecting contaminants and ground sediment, eventually transporting them to water bodies (i.e. streams, rivers, ponds, lakes, etc.). Storm water is also intentionally directed into bodies of water through storm water drainage systems. Storm sewers are used to divert water away from streets, parking areas, rooftops, and other impervious services channeled through a series of piping eventually leading to a storm water collection basin or directly injected into a water body. The EPA wants the public to know that nonpoint source pollution, including storm water runoff is one of the most important sources of contamination of the nation’s waters. According to a nationwide survey, 77 of 127 priority pollutants were detected in urban runoff.

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NW Iowa Planning & Development