National Water Information System (NWIS) and National Ground Water Monitoring Network (NGWMN) Water Level Percentiles for Various Time Periods

This folder contains percentiles from the levels record for monthly data from groundwater wells stored in NWIS and NGWMN. -------------------------------------------- Each of these zip folders contains percentiles calculated on these monthly groundwater levels for the period specified in the title. Both continuous monitoring sites and tape downs were condensed to monthly values by taking the first level measurement that occurred within the month. Sites with more than 33% of month values missing from any decade in the period were excluded. Each daily flow was grouped 2 different ways with flows in the month, and all site values. For each group the percentile/fraction of level ranking was computed for each given flow value. This ranking [...]