Abstract This study used 2010 and 2011 COOP (Co-Operative Observer Program) and AWDN (Automated Weather Data Network) weather observations from Brookings, South Dakota. The study addressed 2010 being a record breaking precipitation year for Brookings, South Dakota. Also addressed was how the rain events during 2010 and 2011 affected the water table depth through the comparisons of daily readings, to other time schedules and a comparison of two different types of metering sticks used to measure water table depth. On a near daily basis during the time of year when the evaporation pan was in service (April 2010 to October 2011) the water table depth was measured as well as the daily amount of precipitation, evaporation and the snow depth at the Brookings COOP station. At this station during 2010, the amount of precipitation was the highest recorded since data have been kept; in fact, it was about 3 standard deviations above the 100+ normal when compared to data from 1894 to 2010. The 2010 and 2011 daily precipitation amounts were compared to the daily water table depth data. What was found was that the water table depth responded within hours of a rain event. Without the water table depth being measured daily most of the details of this rain event and water table depth change interaction would not be seen. The comparison was extended to show that interaction with daily details is lost if the observations are only taken once or twice a month or only the second day after a rain event as is the current practice at other water table depth monitoring sites. The last comparison study compared two types of sticks used to measure the water table depth.

It was concluded that water table depth measurements be made daily because of the interactive dynamics that occurred between rainfall events, snow melting, and water table depths that would otherwise lost. It also suggested that daily readings be made at other stations that measure water table depth, precipitation and snow depth to determine if Brookings is or is not unique in possessing this dynamic relationship.