Introduction
Drake University is a private, mid-sized, co-educational college located in Des Moines, Iowa. The campus is on a 150-acre property that has 84 buildings, 35 associated parking lots and is interspersed with multiple green spaces and commons. Drake University’s enrollment is increasing yearly and is continuing to incorporate new programs, which has sparked the need for new buildings and renovations. As development occurs, stormwater management has become an increasing concern in the minds of students, staff and the Facilities Planning and Management team in regards to the increasing amount of impermeable surfaces present on campus. Stormwater runoff from campus eventually reaches the Des Moines River, a tributary of the Mississippi …show more content…
Studies have shown that bioswales decrease the speed of flows, act as a stormwater detention facility, and allows for suspended solids to settle out (Xiao & McPherson 2011). Moreover, the vegetation plays a vital role in filtering particulates and their associated pollutants as runoff passes slowly through the channel. The pollutants present in the runoff have the chance to be incorporated into the soil where they may be immobilized or decomposed by microbes and plants. Thus, the implementation of a bioswale takes into consideration the hydrological, chemical and biological attributes of a particular area and provides a creative and aesthetically pleasing way of controlling runoff while simultaneously improving water quality, mitigating wetland loss, and offering flood containment. In some states bioswales may even provide economic benefits. This paper is divided into five main sections to reflect the hydrological, chemical, biological and economic considerations Drake University must consider when implementing stormwater management practices and will attempt to answer three main questions of how bioswales will impact Drake’s campus. The three questions are:
1). What is the total impact of a potential bioswale in the Drake University watershed and Des Moines River watershed?
2). To what extent will creating bioswales help …show more content…
Precipitation averages around 34 inches per year, but ranges from 26 inches in the extreme northwest to as much as 38 inches in the southeast. The pattern of precipitation is seasonal with more rain received during the April to September growing season. Measurable precipitation occurs on about 100 days per year. The number days on which amounts exceed 0.5 inch varies from about 15 days in the northwest to 25 days in the southeast. In Des Moines, specifically, over two-thirds of the 34.72 inches of rain falls from April to September and about half of the average annual precipitation falls from May through August. However, annual totals vary widely from year to year and locality to locality. Seasonal snowfall averages 32 inches across Iowa and varies from around 40 inches in northeast Iowa to about 20 inches in the extreme southeast corner of the State. The snow season normally extends from late October through mid-April but significant snows has fallen as early as September 16 (1881) to as late as May 28 (1947). The average number of days per season with snow cover one inch or deeper varies from about 40 days along the Missouri border to around 85 days along the Minnesota border. In about half of all winters, a daily snowfall of five to six inches or more are recorded in southern Iowa and seven to eight inches or more in northern Iowa. December, January and February are normally the
Drake University is a private, mid-sized, co-educational college located in Des Moines, Iowa. The campus is on a 150-acre property that has 84 buildings, 35 associated parking lots and is interspersed with multiple green spaces and commons. Drake University’s enrollment is increasing yearly and is continuing to incorporate new programs, which has sparked the need for new buildings and renovations. As development occurs, stormwater management has become an increasing concern in the minds of students, staff and the Facilities Planning and Management team in regards to the increasing amount of impermeable surfaces present on campus. Stormwater runoff from campus eventually reaches the Des Moines River, a tributary of the Mississippi …show more content…
Studies have shown that bioswales decrease the speed of flows, act as a stormwater detention facility, and allows for suspended solids to settle out (Xiao & McPherson 2011). Moreover, the vegetation plays a vital role in filtering particulates and their associated pollutants as runoff passes slowly through the channel. The pollutants present in the runoff have the chance to be incorporated into the soil where they may be immobilized or decomposed by microbes and plants. Thus, the implementation of a bioswale takes into consideration the hydrological, chemical and biological attributes of a particular area and provides a creative and aesthetically pleasing way of controlling runoff while simultaneously improving water quality, mitigating wetland loss, and offering flood containment. In some states bioswales may even provide economic benefits. This paper is divided into five main sections to reflect the hydrological, chemical, biological and economic considerations Drake University must consider when implementing stormwater management practices and will attempt to answer three main questions of how bioswales will impact Drake’s campus. The three questions are:
1). What is the total impact of a potential bioswale in the Drake University watershed and Des Moines River watershed?
2). To what extent will creating bioswales help …show more content…
Precipitation averages around 34 inches per year, but ranges from 26 inches in the extreme northwest to as much as 38 inches in the southeast. The pattern of precipitation is seasonal with more rain received during the April to September growing season. Measurable precipitation occurs on about 100 days per year. The number days on which amounts exceed 0.5 inch varies from about 15 days in the northwest to 25 days in the southeast. In Des Moines, specifically, over two-thirds of the 34.72 inches of rain falls from April to September and about half of the average annual precipitation falls from May through August. However, annual totals vary widely from year to year and locality to locality. Seasonal snowfall averages 32 inches across Iowa and varies from around 40 inches in northeast Iowa to about 20 inches in the extreme southeast corner of the State. The snow season normally extends from late October through mid-April but significant snows has fallen as early as September 16 (1881) to as late as May 28 (1947). The average number of days per season with snow cover one inch or deeper varies from about 40 days along the Missouri border to around 85 days along the Minnesota border. In about half of all winters, a daily snowfall of five to six inches or more are recorded in southern Iowa and seven to eight inches or more in northern Iowa. December, January and February are normally the