HECTOR O. CONDE

October 2, 2004

CAGRD, Attn. Cliff Neal

Comments: CAGRD Draft Plan of Operation

Although the plan presented September 28 seems to allow continuance with the present recharge and replenishment established goals for the Tucson AMA, the truth of the matter is that the availability of water for the population in the future will not be met with the present recharge methods.

The water should be recharged where the wells are located. The particular topography of the northern part of the Tucson AMA is such that there is a 1800 feet altitude drop between Falcon Valley and Avra Valley. I pick this example which I am familiar with but many areas suffer from the same problem. Almost everybody knows that water does not flow upstream, therefore it may not be necessary for me to explain the physical facts.

To illustrate the point I refer to fig. 1 that shows the altitude changes. Fig. 2 shows a partial map (1) of the area that depicts the depth of the saturated zone. Fig. 3 shows the general direction of the underflow (2). Notice that the subsurface water will flow from Falcon Valley to the Santa Cruz River.

The example of Falcon Valley is illustrative because it is an isolated valley that has outflow, not inflow, and depends on mountainside natural recharge. The area has been designated for development of mainly resort communities with golf courses. Since the golf courses would exceed the daily per capita allowable limit, the well drilling permits were accompanied by a CAGRD recharge permit. To recharge, the only alternative site at the present is Avra Valley.

Fig. 4 shows what the development would do to safe yield in the area. It is clear that there is a water deficit from the start. Data is 2002.

At a water roundtable in Oracle in 2001, Erroll Montgomery stated that the area was not sufficiently studied, but his estimate was a capacity of 1,500,000 Acre feet. He also pointed out that the number could be half of that.

Fig. 5 shows an estimate of the aquifer use in 100 years. Assuming that build-out would occur in 50 years the column called “cumulative” that shows the total water use in the area, indicates that in 53 years the aquifer would be depleted. This also shows that there is no compliance with the 100 year assured water supply statutory requirement. Of course if the aquifer is half the stated capacity, it would be 25 years.

One example of politicians voting on the wrong side of the issue is Oro Valley. I worked for about two years on a renewable water resource committee. We recommended that, after a recharge study that cost the town tens of thousands, we bring CAP water, recharge the aquifer, and pump it out. The council decided to bring effluent. The town has a yearly 9,000 A/f deficit, one third due to golf courses. Affluent would allow more golf courses. CAP water would not.

The CAGRD is an elected body. As such it is supposed to act in defense of the voter’s interest. For starters, it would be appropriate that the board recommend to the legislature that all recharges take place in the areas where the wells are drilled. It will be a step to assure the population that their properties would not have zero value some day, either because of subsidence or lack of drinking water or both.

Sincerely,

Hector Conde

1 Cooley, 1973, Alluvial deposits…USGS 1-844-C

2 Osterkamp, 1974, Ground water velocities… USGS i-844-K