Date of Award
Doctor of Philosophy
Civil, Construction, and Environmental Engineering
The Hallett Quarry gravel-pit lake system is an active sand and gravel extraction operation located on the South Skunk River flood plain in central Iowa 0.4 km (0.25 mi) north of the City of Ames. This system served as a supplemental water supply for Ames in 1977 during a period of severe drought. After this experience, it was apparent that a management plan was needed for the area, with one of its objectives being the protection and optimization of future water quality;A limnological investigation of the three gravel-pit lakes at Hallett's Quarry and the west gravel-pit lake at Peterson's Quarry was conducted to obtain baseline water quality data to assess the present water quality of these gravel-pit lakes. During this 16 month investigation, 20 water quality parameters were monitored and evaluated. The four gravel-pit lakes were found to be eutrophic, exhibiting annual temperature and dissolved oxygen cycles which are typical of dimictic, cool, north temperate eutrophic lakes. Water quality differences were found to exist not only between the Hallett's and the nearby Peterson's Quarry gravel-pit lakes but also among the three gravel-pit lakes at Hallett's Quarry;A stormwater quality monitoring program was conducted in 1980-1981 to quantify the stormwater pollutant loads to the Hallett Quarry gravel-pit lake system from both the urban and agricultural portions of the watershed. The scope of this program was reduced due to the occurrence of below normal amounts of precipitation. Time and flow weighted concentrations of selected pollutant parameters for the five sampled storm runoff events were 10 to 100 times greater from the agricultural than from the urban portion of the watershed;A modified version of the Vollenweider input-output model was used to predict the future water quality of the Hallett Quarry gravel-pit lake system under various watershed land use, drainage, and lake configurations. It was concluded that the dominant factor controlling the future water quality of the Hallett Quarry gravel-pit like system is nutrient input due to stormwater runoff. A management plan to optimize the future water quality of the gravel-pit lake system should be oriented towards reducing this nutrient input into the system. Bypassing all or part of the storm-water runoff is an alternative now being considered.
Digital Repository @ Iowa State University, http://lib.dr.iastate.edu/
Larry Michael Antosch
Antosch, Larry Michael, "Management of a gravel-pit lake system to optimize future water quality " (1982). Retrospective Theses and Dissertations. 7021.