Several people with surface water rights in the Nambé, Pojoaque and Tesuque stream system — including Gerald Peters and his son Soren Peters — have challenged the priority date given their ditches by the New Mexico State Engineer. They'll now have a chance to prove their ditches were used for irrigation earlier than the official year given by the state. In addition, their neighbors on other ditches can challenge the Peters claim and other protesters on any proposed changes to priority dates.

The action is another important step in the Aamodt case filed 43 years ago to settle the water-rights claims by Nambé, Tesuque, Pojoaque and San Ildefonso pueblos. The pueblos, the state, the city of Santa Fe and Santa Fe County in 2006 reached a settlement that needs congressional approval. This year, Congress has steadily advanced legislation to ratify and fund the settlement, but no final act has been passed. Some of the nonpueblo landowners in the valley with domestic wells have fought against the settlement for years and continue to oppose portions of it.

Meanwhile, the federal district court must finalize the priority dates on acequias in the valley as part of the settlement. Priority dates were given by the state to more than 70 streams in the area and people with water rights had an opportunity to ask for a change in the date.

Priority dates on irrigation ditches are a critical part of New Mexico's water law and the wheeling and dealing by cities and developers over water rights. New Mexico follows a "first in time, first in right" approach to water — the first person, or ditch, to use water beneficially has the senior claim on the water. The ditches with the oldest priority dates receive their water first off a stream.

The pueblos are recognized as the first people in the valley to use water for farming and other uses, so they have first rights to water.

Priority dates on the acequias in the Pojoaque Valley range from 1728 within the Rio Tesuque to 1907 on parts of the Rio en Medio. Gerald Peters, for example, believes the priority dates on several irrigation ditches fed by the Rio en Medio should be older than the those given by the state. The state gave the Questa Ditch a 1907 priority date; Peters believes it should be 1899.

According to a legal notice published Friday in The New Mexican, people who have challenged their ditch's priority date and those who want to challenge any changes have until Dec. 31 to file notice they intend to participate in the court proceedings. They must also attend a pretrial conference Jan. 13 with the special master reviewing the priority dates. This is the only opportunity people with surface water rights will have to participate in the adjudication of priority rights, according to the state. Anyone who doesn't participate won't be able to object later.

Contact Staci Matlock at smatlock@sfnewmexican.com.