Find more about groundwarer levels and statistical charecteristics of well networks. Active Water Level Network-- wells measured at least once within the past 13 months. Climate Response Network-- wells that monitor effects of climate variability such as droughts. Real-time network-- wells measured at 15-60-minute intervals and transmitte to the Internet every 1 to 4 hours. Long-Term Groundwater-Data Network-- wells with at least 20 years of measurements.