Metropolitan Domestic Water Improvement District - Tucson, Arizona USA
The drought continues to impact Metro Water’s wells. The District hydrologists completed an analysis of last year’s well levels that shows most wells had declined from 5 feet to 13 feet. The Board of Directors reviewed this information at its July meeting.
“The data unfortunately shows that our wells continue to decline at a faster than anticipated rate due to the drought,” said Mark Stratton, Metro’s General Manager.
Metro Water has 29 active wells within four well fields in the Northwest with then 5 more wells in the Hub service area. South of Magee Road and along the Cañada del Oro Wash, wells showed an average decline of 6 feet. Wanda well near Magee and Wanda Roads dropped by 13 feet. Three wells near Tucson National Resort were shown have rose by 6 feet, which appears to be an odd anomaly to the overall decline.
The more significant trend is the average decline over ten years. For example, in the western portion of the CDO, some of the District’s more productive wells have declined more than 40 feet over ten years. This is primarily due to the effects of the drought that the Southwest has experienced and the lack of natural stream recharge within the CDO basin.
“This does not mean we are going to run out of water,” added Stratton, “but it does mean we need to actively proceed with our plans to more directly use our renewable water resource and conserve our groundwater.”
Metro Water does have a 100 year assured water supply designation from the State of Arizona. Under that 100 year designation, Metro is expected to be using fully its renewable supplies by 2025. Based on the current groundwater declines, Metro is working hard to using renewable water well before 2025.
“Metro has always known that it cannot rely forever on its groundwater and has looked at ways to use renewable supplies,” said Stratton. As water tables drop, production rates are reduced, the energy cost to pump the water increases, water quality issues possibly develop and overall capacity decreases.
Declining water levels is not just unique to Metro but are occurring throughout the Tucson area. For example, 14 wells in the Oro Valley area have declined by 5 to 15 feet.
Metro Water has an allocation for Central Arizona Project water as well as ownership of effluent generated from its service area. With the groundwater levels declining faster than expected, a greater urgency exists for pursing the use of those resources.
Metro Water has been actively working with other Northwest area water providers, the State, and the US government to investigate the best way to maximize those resources.
Compounding the problem is increased water usage in other water provider’s service area due to growth north of Metro Water District. As more water is used to meet this growing demand, along with a reduction in the natural recharge of storm water runoff, the end result is a more rapid decline of the aquifer.
Arizona and most of the Western US is in the eighth year of a drought. While Arizona and the West enjoyed a wet winter this year, it is yet to be seen if it is an atypical wet year in the middle of the drought or if next winter will also bring more moisture.
Summer monsoons are welcomed but it is the winter rain and snowfall that are critical for slowing down or ending a drought.
The next newsletter will detail further how it is addressing these issues.
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Water Conservation 
