Look beyond new wells for water needs

Neva Van Peski |

5/11/2008 - 5/11/08

The often-stated goal of the Buckman Direct Diversion is to allow us to rest our aquifers, conserving our groundwater for use in dry periods when surface flows cannot meet our needs. Perversely, the imminent development of the BDD is now being used to justify Santa Fe County's proposal to add a number of new wells to the county water system. The county has drafted a Conjunctive Management Plan for the Santa Fe Basin whose major purpose appears to be to justify the need for these wells.

The plan points out that flows on the Río Grande are variable, and that when they are sufficiently low, diversions of native Río Grande water from the BDD will be curtailed. It states that in the past seven years, flows were low enough, for several days, to trigger some curtailment. It speculates that climate changes may make the Río Grande more susceptible to droughts in the future, and points out that if there were much lower flows than any seen in recent years, such curtailment could occur for several months at a time.

The plan concludes that wells are needed to back up variable surface water supplies. It proposes that the total amount that may be diverted in any year from the county's proposed wells be based on a 10-year average of pumping. For example, on the basis of the 200 acre feet of rights the county believes will be available to its water system, it would be allowed to pump 620 acre feet in each of three years, plus 20 acre feet in each of seven years. In any year, pumping would be distributed among the wells in whatever way is considered best in that year.

The plan is correct in stating that some backup is needed for the water the county expects to get from the BDD. What is missing from the plan is any realistic discussion of alternatives to drilling new wells in the local aquifer.

Such a discussion should begin with an accurate assessment of the county's need for backup. Short-term curtailment of native Río Grande water from the BDD can be met either by drawing on the 500 acre feet annually already promised by the city water system or by diverting the county's San Juan-Chama water, which is not subject to curtailment, during that period. No new wells are needed for that.

Real long-term disaster (horrible accident, no water at all from the BDD for a long time) will require the use of groundwater. How much? If the county follows the wise policy of considering 10 percent of its 2,200 acre feet of total water supply to be a reserve, and if, in the case of a complete failure of the BDD, it asks its customers to reduce use by 10 percent, existing agreements with the city will supply all but 432 acre feet annually of the water needed by the county system.

There are several possible alternatives for obtaining 432 acre feet of groundwater in the event of complete failure of the BDD. For example, the county could contract with the city to deliver 432 acre feet a year for the duration of the disaster. There may other acceptable solutions.

The purpose of this letter is not to urge a particular solution, but rather to point out that a more accurate description of the need for backup could lead to a better solution than the Conjunctive Management Plan proposes.

Hearings on the plan will be scheduled in the near future. They should provide an opportunity to discuss ways to provide a more economical groundwater backup, and better protection for the local aquifer, than drilling new wells for the county water system.

Neva Van Peski is a concerned Santa Fean who closely follows water issues.