This information comes from Jack McCormick at The Water Resources Dept. in Prescott, Ph 778-7202. The Water Resources Dept. is in three areas of Arizona, Phoenix, Tuscon and Prescott. When water companies or towns want to draw water from an aquifer they have to show that there is a 100 year supply before they can take the water. These three areas are the only areas in Arizona that this applies, so we are fortunate that we fall just within the boundaries of the Prescott Water Resource Dept. On line go to WWW.AZWATER.GOV.


Lonesome Valley Aquifer
  That is the name of the aquifer that is in the Dewey-Humboldt area. According to 1988 report, Arizona Department of Water Resources Bulletin 5, Water Resources of the Northern Part of the Aqua Fria Area, Yavapia County, Arizona, the aquifer holds about 800,000 acre feet of water. Most of the water is held in sand, clay, silt, rock substrate basin that is porous beneath and along the sides of the Aqua Fria River. The Aqua Fria Basin starts in Prescott Valley, goes to the base of the foothills on each side of the valley and ends at Humboldt. The depth of the aquifer is estimated to be about 1000ft deep at Humboldt; about 500 feet deep at Young's farm and gets shallower as it goes north. The Aqua Fria River is the top of the aquifer, so where it flows out of the ground on Young's Farm that is the water table for the area. Water flows into the aquifer from several sources. On the East side we get the drainage from the Black Mountains (Mingus Mountain area). On the north side there is an underground uplift of rock about where highway 89A runs. The north side of 89A drains to the Chino Valley aquifer and then to the Verde River. The south side drains to the Aqua Fria River and into our aquifer. The Bradshaw Mountains on the west side provide most of our water since it drains a larger area. One of the main contributories is Lynx creek. At Humboldt on the south end of the aquifer there is another uplift of rock damming the aquifer. The excess water of our aquifer overflows forming the Aqua Fria River. A quick check on the health of our aquifer can be determined by how much water is overflowing at Humboldt. There is a web site that monitors the flow every 15 minutes at Humboldt. HTTP://waterdata.usgs.gov/az/nwis/uv?09512450


Users of water
  Since Prescott Valley is closer to the source of water than we are, they have first chance to use it. That means as they grow and build more dense housing and if they don't get their water from a different source they will start pulling down our water table so that the Aqua Fria no longer overflows. Fortunately they are trying to get their water from the Chino Valley aquifer. If they do, this will help us since the waste water goes to the sewage plant which drains to our aquifer. Private wells are exempt from the 100 year rule. That means you can pump water (35gpm) and irrigate up to 2 acres without getting special permit for irrigation. If you want to irrigate anything over 2 acres you need to go through the Arizona Water Resources Dept to get permission. Young's Farm uses about 60 acre feet of water a year for irrigation. This is about the amount of water that would be needed for the houses if built on the current zoning of 1.62 acres for this area. The overflow from Humboldt goes to the Mayer water basin. Mayer is outside the Prescott Water Resources Dept. so the 100 year rule does not apply to them. So if we dry up the Agua Fria River it will affect their aquifer and they will have no one to complain to unfortunately.


Water Credits
  When farmers retire their farms and stop irrigation they get credits for the water that they are no longer using. They can now sell these credits to organizations that need more water. These credits are quite valuable, Quailwood had to spend over a million dollars to get enough water credits for their subdivision. Water credits can only be used to take excess water from an aquifer. They can not take water if it affects neighboring wells unless the wells affected sign off on it. This usually means that the owners of the wells get paid a good some of money to relinquish their right to the water. The state in 2000 decided to start doing away with these water credits at 4% a year until the year 2025 when there would be no more water credits. Young's campaigned the state to have this provision to start taking affect in the year 2010. In 2010 the farmers would lose 40% of the water credits (10 X 4=40) this would make their land less desirable for large scale developers who need a water system to supply all the houses. So the land is probably worth more now for development than in 2010.


Salt River Lawsuit
  Except for the Little Colorado River almost all rivers in Arizona drain into the Salt River. Over 30 years ago the people in the Phoenix area laid claim to all the surface water and subsurface water on the tributaries of the Salt River. Nobody knows when if ever that the courts will decide the status of the water. So far they have been waiting the Federal and State Government to get their water policies lined out before they rule. The federal is mainly involved over the Colorado River division of water among neighboring states. This looks like this may be settled. If Phoenix wins the lawsuit they could cap all the wells that draw water from the various river water basins. This is unlikely to happen. What most people think will happen is that they will grandfather the existing wells in and not allow any more wells in the various river basins. This is all speculation until the lawsuit is decided. Basically what this means even though you have a legal well you may not have a legal right to the water from that well.

If you would like more information or to check to see if I got my facts straight I urge you to call Jack McCormick ph 778-7202 at the Prescott Water Resources Board.

Jack Hamilton


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