(Click here for Environmental Resources Goals, Policies and Strategies)
Intent
To preserve and protect the fragile soils, wildlife, steep slopes, fragile drainage ways, vegetation, and lakes and streams that make up Afton’s natural features. Additionally, to protect Afton’s environmentally sensitive areas so as to preserve the health and safety of the residents, the aesthetic qualities of the landscape and the air and water quality.
Background
The citizens of Afton have a high regard for their environment. While the city is only fifteen miles east of downtown St. Paul, there is a world of difference between Afton and the urban and suburban development to its west. Citizens desire to keep the city as natural and rural feeling as possible, while still enjoying the benefits of being located close to a major metropolitan area.
Afton’s natural features exist in gently rolling uplands bisected by deeply cut ravines, drainage ways, and streams that flow into the St. Croix River. This type of topography, while uniquely defining, presents distinct challenges, particularly with stormwater and agricultural runoff. Low density development is interspersed amongst environmentally sensitive areas, such as trout streams, bluffs, ravines, wildlife habitat, wetlands, groundwater resources, steep slopes, and floodplains. The commitment to preservation is strong; sixty-one percent of residents believe there should be public investment, or taxes, to preserve these sensitive areas[1].
(SENSITIVE AREAS MAP)
By identifying and then protecting its natural resources, Afton will be able to accommodate future development without compromising the assets that make the city an important environmental area. Natural resources in need of preservation include viewsheds, wildlife, soils, topographic features, vegetation, drainage areas, groundwater, and energy.
Soils
The different types of soil in Afton are directly attributed to glacial till[2]. Most of the Afton area includes soils overlying bedrock having slow percolation rates, steep slopes, periodic flooding and seasonal high water tables. There are some areas in Afton that have been subject to mining.
These geologic features have created deep ravines and drainage ways. Soil types associated with these features are generally unsuitable for development due to their instability, high erosion potential and low absorption rates. Development in these areas needs be monitored to prevent further soil degradation.
The Washington County Soil Conservation District issued a soil survey in April 1980. Different types of soil have been categorized in terms of supporting future development, a rural atmosphere, farming, groundwater protection, wildlife habitat, and a biological diversity for its citizens, flora and fauna[3]. The soil survey indicates that nearly 50 percent of the soils in Afton have a severe limitation for on-site sewage treatment systems. Nearly half of the soil with a severe limitation is located in the areas with shallow bedrock.
(SOIL SUITABILITY MAP)
Not only is there insufficient soil depth to treat septic effluent in these areas, the effluent may also flow through fractures in bedrock and enter water wells without being properly treated[4] in the soil. Also, installation of septic systems on slopes over 12 percent may result in erosion, lateral seepage and downslope flow of effluent[5]. There is a major need in the Afton area for properly installed and maintained septic systems so that development can continue while presenting few problems to landowners, neighbors, and the environment.
Some of the City consists of prime agricultural soils[6] and soils of statewide importance. While soils are a major factor in determining the importance of land for agricultural purposes, there are many other factors that influence whether a land is most suitable for agricultural uses. In Afton, the prime agricultural lands tend to be those areas most easily developed, having few topographic or environmental constraints. Yet, these areas provide some of the broadest expanses of non-fragmented open space in the city and are thus critical preservation areas.
(PRIME AGRICULTURAL LAND MAP)
Topography
Afton’s steep slopes are a result of erosion by flowing water. It is vital to the community that these drainage ways be protected and maintained. It is essential that every attempt be made to limit the amount of additional stormwater and agricultural runoff that flows through these drainage ways, many of them in or near the Old Village. Afton currently protects slopes with a grade over 18 percent and slopes with a grade over 12 percent if the soils on such slopes are deemed fragile[7]. Continued care must be taken when allowing the development in the upland areas of the City.
(MAP OF TOPOGRAPHY AND STEEP SLOPES)
Vegetation
The vegetative cover is an essential part of the City of Afton’s natural environment. In an area where there is such dramatic topography, damage to the vegetative cover can result in such things as increased erosion and stormwater runoff, increased danger of flooding and siltation, lessening of water quality, loss of landscape diversity, decreased land values, detriments to surrounding wildlife and ecosystem, and degradation of soil and air quality. The tree cover is predominant where there are steep slopes, areas not being farmed and along watercourses and drainage ways. The vegetative cover consists mainly of deciduous trees, with several areas of planted conifers. Drainage
Afton is divided by major drainage ways[8]. These include: Valley Creek, South Fork Valley Creek, Trout Brook and other major ravines and drainage way tributaries to the St. Croix River. Much of the surface water that flows from Afton into the St. Croix River goes through or near the Old Village. It is vitally important to the safety of the Old Village, and to the health and vitality of the St. Croix River, that these drainage ways be protected and stabilized and the amount of stormwater runoff through these drainage ways are kept to a minimum.
Valley Creek, with headwaters in northwestern Afton, is a spring fed stream flowing through an exceptionally fragile environment in Afton to its point of discharge into the St. Croix River near the eastern limits of the City. This high quality stream is recognized as a trout habitat unique to the metropolitan area and one of the five or six best in the State of Minnesota. It is also home to the rare Blanding’s Turtle, and serves as a natural habitat for many species of waterfowl, beaver, and other wild animals. This creek has been carefully protected by private and government interests and it is the policy of the City of Afton to continue this protective stewardship in cooperation with the Minnesota Department of Natural Resources and the Valley Branch Watershed District.
The City of Afton includes the Valley Branch Watershed District, the Middle St. Croix Watershed Management Organization, the Lower St. Croix Watershed Management Organization, and the South Washington Watershed District.
(MAP OF SURFACE WATER FEATURES)
Groundwater
Afton encourages that groundwater be maintained in its natural condition, free from any degradation caused by human activities. Because several areas in the City that have been mined, it is essential that groundwater is monitored to prevent unfiltered septic effluent from damaging the aquifer.
Mining removes the topsoil and sub-soils that filters runoff and sewage system effluent. Systems installed in these soils may result in the effluent moving quickly and untreated through the coarse soils to the water table resulting in pollution of water wells. This is of even greater concern if the area is one of groundwater recharge. Areas of groundwater recharge are criticial areas that have soil characteristics that are conducive to rapid perculation of water from the surface into the substrate and ultimately into the local water table and connected hydrologic systems (wetlands, lakes, and rivers). Pollution of the groundwater water supply can have a devastating financial and environmental effect on a community and its residents.
Energy
In conjunction with its concern for the environment, the community of Afton is also concerned about energy waste. As a sparsely populated rural community, the City will encourage all feasible methods of conserving energy.
