Hydrographic Surveys
Lake Decatur Basin 6 Dredging, Decatur, Illinois
The City of Decatur purchased hydraulic dredging equipment in 2003 and made a decision to utilize City Staff to perform dredging operations in Basin 6. These operations began in 2004 with approximately 1,500 acre-feet of sediment to be removed from this basin. Lake Decatur has six basins. Chastain performs annual hydrographic surveys for the City to monitor annual production. Chastain utilizes our boat equipped with GPS, a recording fathometer and Hypack software to perform all work in the field. Chastain creates a digital terrain model of the lake bottom for comparison to previous production and volume calculations. Three drawings are produced each year detailing the work performed with contours and a summary of annual dredge production. This work has allowed the City of Decatur to evaluate its progress and make critical decisions regarding the future of the city dredge program.
Hydrographic Lake Surveys, Central Illinois
Clinton Lake is a manmade lake constructed in the late 1970's. The lake serves as a recreational facility for the community as well as a source of water to cool a power plant. In addition to the main dam structure there is a secondary submerged dam near the plant facility that wound impound water for emergency operation of the plant should the main dam fail or in cases of severe drought. This area is referred to as the Ultimate Heat Sink (UHS). There are strict guidelines as to the minimum water volumes required for the plant. Chastain performs annual surveys of the UHS to verify the plant meets minimum water volume capacities. These surveys are performed utilizing our 18 foot boat equipped with GPS, a recording fathometer and Hypack software. The UHS is surveyed each year in its entirety. A digital terrain model is created of the bottom of the UHS and calculations are made to determine the available water capacity. A report on the capacity and condition of the UHS is furnished to the client on an annual basis. Sediment continues to build up since the UHS was last dredged in 1990. Chastain's work provides the client with assurance of adequate water supply per policy as well as planning for future dredging.