Tuesday, March 15, 2011
GMD 4 Rain - Pumping - Water Table Relationship
One of these days I'm going to update this graph because it's so instructional. You should note also the three trend lines included on the graph. While the in-season rainfall and the water level change trend lines are relatively flat, the reported pumped water trend line is decidedly downsloping.
Why, you ask, should the water level change line NOT be upward sloping if less water is getting pumped? It's because consumptive use drives the water level changes. While pumped water is actually declining due largely to irrigation efficiency improvements, the consumptive use of the reduced water pumped has held more or less steady. To affect the water level change trend line, we need to reduce consumptive water use - or, make it rain more.