March, 2006
Welcome to the monthly Prairie Trail newsletter! The objective of this newsletter is to keep you informed about Prairie Trail with relevant information and insights.
Prairie Trail is a significant development for Ankeny and for Central Iowa, and our goal is to communicate with our stakeholders and partners on a regular basis.
Conservation Design in Prairie Trail
Storm water management may not be the first thing you think about over your morning coffee, but Ankeny city leaders and staff think about it often. They know it is vital in order to continuously make Ankeny a better place to live. If managed correctly, storm water runoff can be turned into a neighborhood and community asset to be enjoyed each day of the year.
The City of Ankeny participates in Central Iowa’s Growing Green Communities initiative, which addresses the impact of storm water runoff in the region. One of the annual goals of the City Council is to implement storm water management practices in the development of Ankeny. Using conservation design techniques, City planners hope to turn the common negative impacts of storm water runoff into positive development attributes.
Conservation design, also referred to as low-impact development, uses several site design and planning techniques that retain the water on site and allow the water to infiltrate the ground. The agreement between the City and DRA Properties for the development of Prairie Trail requires that the principles of “conservation design” be incorporated into the storm water management system.
In many developments there are roads, parking lots, rooftops and compacted turf areas that do not allow the rain water to infiltrate the ground. The runoff may be detained, but eventually it goes through the storm water system and into a waterway. Often this results in silt and debris flowing into the waterways following a rainstorm.
One of the techniques used to capture runoff from roadways and parking lots is the construction of bioretention cells. This feature is a shallow depression that includes a drain tile bedded in gravel, with a soil and compost mix above the gravel, and native shrubs and trees planted on the surface. The bioretention cells take the storm water runoff from roadways and parking lots and retain it while it is filtered through the plants and soils in the bioretention cell. The water eventually seeps into the groundwater or into a drain tile that feeds a waterway or a pond.
The storm water runoff of residential neighborhoods is managed through the use of bioswales as an alternative to storm sewers. Bioswales use the same techniques as bioretention cells by creating subsurface and plant life filtration systems. The storm water from the yards of neighborhoods is directed to the series of bioswales and filtered into the groundwater.
Individual property owners can use conservation design to manage storm water runoff on their property through the use of rain gardens and landscaping with native plants. Rain gardens are small perennial gardens that use native vegetation to filter runoff from roofs, driveways and patios. The rain gardens are strategically placed on residential lots to capture the runoff before it gets into a storm sewer system. The planting of native plants on residential lots serves to retain the rain water for use by the plants. An informational video on how to build a rain garden will be broadcast on Ankeny cable channel 7 beginning in March 2006.
The storm water runoff that is captured by the features described above will be part of a larger storm water management system in Prairie Trail. The larger system will use a series of ponds and green corridors to tie all of the individual storm water management features together. The ponds will be placed throughout the development and will be recharged by the groundwater from the individual storm water management features. The ponds will have their own level of aquatic life that is enhanced by the constant recharging of groundwater.
The green corridors in Prairie Trail will have native plantings and will connect the ponds to the neighborhoods. A new ecosystem will develop in and around the ponds, the green corridors and the individual storm water management features. The ecosystem will include fish and aquatic life in the ponds and butterflies, bumble bees and birds along the corridors and in the neighborhoods. The ponds and green corridors in Prairie Trail will enhance the environment and provide countless opportunities for residents and visitors to enjoy the peace of being near water and plant life.
The use of conservation design principles in Prairie Trail will take the difficult challenge of managing storm water and transform it into an asset that can be enjoyed by all the people of Ankeny for years to come.
