OSE Approval of the 2025 Rio Chama Sharing Agreement

Elizabeth K. Anderson, P.E.
State Engineer
May 5, 2025
RE: OSE Approval of the 2025 Rio Chama Sharing Agreement

Greetings:

The Office of the State Engineer (OSE) has approved the 2025 Rio Chama Basin Sharing Agreement, enclosed. Implementation of the sharing agreement shall be triggered by daily average flows at USGS gaging station 08284100 (La Puente) as follows:

• For post-1907 surface water diversions located above La Puente: Sharing will begin when the daily average flow at La Puente reaches 70 cubic feet per second (CFS), consistently.

• For all other diversions: Sharing operations shall commence when the daily average flow at La Puente reaches 50 CFS, consistently.

OSE staff will engage with mayordomos or other representatives of pre-1907 acequias and ditches located above La Puente to encourage voluntary reductions in diversions when flows range between 70 and 50 CFS.

The following Rio Chama subbasins are excluded from participation in the 2025 Sharing Agreement due to the absence of sufficient subbasin data: El Rito, Ojo Caliente, Cañones y Polvadera, Canjilon, Rio Gallina, Rio Cebolla, Rio del Oso, Rio Puerco, and the Rio Nutrias.

OSE is appreciative of your participation in the development of the 2025 Sharing Agreement. Staff will reman in contact with the sharing parties and mayordomos as native Rio Chama flows decline and implementation of the agreement becomes necessary.

Respectfully,
Lorraine A. Garcia
Deputy District Manager
Water Rights Division
[email protected]

CC:
John Romero ([email protected])
Ramona Martinez ([email protected])
Cindy Stokes ([email protected])
Myron Armijo ([email protected])

2025 Shortage Sharing Agreement and Schedule

Parties

Ohkay Owingeh
Rio Chama Acéquia Association member acéquias
Acéquia de los Salazares, Acéquia de Abeyta y Trujillo, Acéquia Valentin Martinez,
Acéquia de la Puente, Acéquia de Tierra Azul, Acéquia de Jose Ferran, Acéquia de Jose Pablo Gonzales, Acéquia Mariano, Acéquia de Manzanares y Montoya, Acéquia de Quintana, Acéquia del Rio de Chama, Acéquia de Jose V. Martinez, Acéquia de los Gonzales, Acéquia de los Martinez, Acéquia de los Duranes, Acéquia de Chamita, Acéquia de Chili y la Cuchilla, Acéquia de Hernandez, Acéquia Barranco, Acéquia Suazo.

Acéquias Norteñas member acéquias
Acéquia de Los Brazos, La Puente Community Ditch, Ensenada Community Ditch, Parkview Community Ditch, El Brazito & Lateral Acéquia, Acéquia del Bordo, Acéquia del Llano, Acéquia del Brazito, Acéquia de la Otra Banda, Acéquia el Pinabetal (Canjilon), Acéquia de Pinavetal (Cebolla), Cebolla Acéquia Madre, Acéquia de Tierra Amarilla, Cañones Arriba Ditch #1, Barranco Community Ditch, M-B Community Ditch, Plaza Blanca Community Ditch, Porvenir Ditch, Village of Chama Community Ditch, Willow Creek Community Ditch and the Valley Ditch.

Basin Wide Rules

1. The Water Masters will administer the sharing schedule in accordance with the included schedules. The Water Masters may suspend curtailment in whole or in part as basin conditions allow.
2. Any diverters on the shortage sharing schedule that are non-compliant with the agreement may be suspended for a week from the schedule at the Water Master’s discretion.
3. For diverters that are not included in the sharing schedule, the Water Masters will administer according to AWRM.
4. For the 2025 season, because of anticipated very low-flow conditions, the Water Master and the Sharing Parties may hold weekly meetings once higher flows from spring runoff start to subside (perhaps as early as May). The purpose of the meetings may include sharing of information on hydrologic and irrigation conditions, and to determine and take additional measures and cooperation that are needed to provide for equitably sharing and to carry out the intent of the shortgage sharing agreement.

Lower Chama Sharing Party Rules

1. Ditches can alter the schedule by trading allocations with approval of both ditches and the Water Master. Any alterations to the RCAA base schedule must be submitted to the Water Master the Sunday before the group start day for the ditches requesting an alteration.
2. RCAA Ditches and Lower Chama diversions may turn on no earlier than 7 am on the first day of their scheduled period and must turn off by 7 am the morning after their last scheduled day.
3. Ohkay Owingeh may use any tailwater that is available on Acéquia de Chamita’s days.
4. Ditches that cannot divert their full allocation shall notify the Water Master immediately. The Water Master will notify Ohkay Owingeh of any available surplus water for its bosque use first. Ohkay Owingeh will no more than 1 hour after being notified of available surplus water notify the Water Master that it intends to use all or some of the available surplus water. Ohkay Owingeh will make every effort to respond promptly. The Water Master will make any remaining surplus water available to other diverters by priority, as available.
5. The Water Master shall shut off diversions to the Acequia de Chamita if, due to a violation by a Chamita Parciante of the water sharing schedule, flows at the State Engineer Yungeh Gage drop below the cfs rate allocated to Ohkay Owingeh under the water sharing schedule after reasonable carriage losses have been subtracted. The curtailment of the Acequia de Chamita diversions based on the flow rate at the State Engineer Yungeh Gage will remain in effect for the remainder of the week in which the schedule violation occurred. Diversions shall not be resumed until Ohkay Owingeh’s next turn on the water sharing schedule. If Ohkay Owingeh uses an alternative point of diversion, the Acequia de Chamita must reduce its diversion at the direction of the Water Master to balance total diversions serving Ohkay Owingeh for the rotation. Ohkay Owingeh, the Water Master, and RCAA may agree to alternative enforcement measures, as appropriate.
6. If there is an active carriage agreement, there will be no restrictions in the Lower Chama. The OSE shall be provided with a copy of the 2025 carriage agreement at least one week prior to commencement of curtailment. The OSE shall be notified three (3) business days prior to when the carriage agreement is no longer active.

Upper Chama Sharing Party Rules

1. Post-1907 diversions will reduce diversions to 50% of their allocated administrative flow rate at 70 cfs and to 40% of their allocated administrative flow rate at 50 cfs. Pre-1907 diversions will reduce diversions to 50% of the allocated administrative flow rate at 50 cfs. See table 2.
2. The Water Master will work with mayordomos or other representatives of pre-1907 and post-1907 diversions located above La Puente to make voluntary reductions between 70-50 cfs at La Puente in an attempt to delay curtailment for more senior diversions in the Lower Chama.
3. At the determination of the Water Master, diversions may be reduced to 50 cfs limitations any day instantaneous flows at La Puente fall under 50 cfs.
4. Irrigation ditches will be limited to livestock use only after July 31 if La Puente is less than 50 cfs.
5. The Water Master may restrict livestock diversions based on basin conditions. Livestock flows will be determined by the Water Master based on livestock need and water supply.
6. Diversions shall bypass livestock water to support downstream livestock demands within their sub-basin. The Water Master will inform diversions of downstream livestock needs and determine the minimum bypass necessary to meet those needs.
7. No diversion shall take all the available water at their point of diversion and dry their stream reach if there are downstream irrigation diversions or livestock needs within their sub-basin.
8. Diverters may voluntarily work together to allocate the supply among themselves (for example by employing ditch rotation), so long as the total diversion of participating ditches does not exceed the total maximum diversion allowable to those ditches. In addition under low-flow conditions, a single ditch or ditches may aggregate their cfs allocation over fewer days per week rather than diverting seven days per week, based on a schedule approved by the Water Master.
9. For the 2025 season, when the flow at Cañones Ditch #1 diversion falls below 4.0 CFS, daily diversions on Cañones Creek located upstream of Cañones Ditch #1 diversion will be limited to livestock use only. Irrigation by upstream diverters will be allowed every other Sunday unless further restricted at the discretion of the Cañones Ditch #1 Mayordomo to ensure all parciantes for Cañones Ditch #1 are able to adequately irrigate their properties. Diversions into ponds will not be allowed at any time when the flow at Cañones Ditch #1 diversion falls below 4.5 CFS.
10. For the 2025 season, all diversions on Tierra Amarilla Creek located upstream of the Tierra Amarilla Community Ditch diversion will be limited to livestock use only when the flow at the Tierra Amarilla Community Ditch diversion first falls below 2.00 cfs. When flow at the Tierra Amarilla Community Ditch diversion is between 2.0 and 5.22 cfs, irrigation by upstream diverters will be limited to Sundays.
11. For the 2025 season, the Sharing Parties have identified the likely need to include additional triggers for further reduction, for example when the allocated administrative flow rate drops to 35 cfs, post-1907 diversions will be further reduced; and when the allocated administrative flow rate drops to 25 cfs, pre-1907 diversions will be further reduced. These additional measures will be the subject of the weekly meetings described above.​

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2025 Lower Chama Sharing Agreement

*The diversion values shown in Table 1 are by way of example and are based on the availability of 48 cfs at La Puente. The daily diversion limits may be less as the native flow at La Puente decreases.

2025 Shortage Sharing Agreement and Schedule