The observation wells are located at the various sites as indicated on the map. They are dedicated wells, used only for the purpose to monitor the water table. The wells are measured on the first day of each month, except January and February. During the high usage months of July and August, the wells are also measured on the fifteenth.The data for the observation wells will be updated monthly, except January and February.The rain Gage network stations were designed, set up, and are maintained by the Illinois State Water Survey under contract with Imperial Valley Water Authority.Local observers perform weekly rain Gage maintenance at 11 sites, while the other nine rain Gages are serviced monthly by a local person trained and paid by the Illinois State Water Survey. As needed, a Champaign-based scientist visits the network to perform maintenance and repairs.The map shows the locations of the sites, and the data table shows the amount of precipitation collected on a monthly basis. Also the monthly average compared to the previous year.The estimated gallons withdrawn by agricultural irrigation is shown, and is compared with several previous years. A formula was devised to determine the gallons used by irrigation. The results of this formula compares favourably with the study conducted by the Illinois State Water Survey in the years 1988 and 1989.