Final Report for SW98-060
Irrigation in San Miguel County is predominately accomplished by Acequia Systems. Acequias are historic irrigation ditches which are community oriented and traditionally Hispanic. This project will broaden efforts to introduce water management to traditional water users, a critical link to sustainable agriculture. Water management technology will help farmers manage soil moisture and fertility. In a semi-arid region prone to severe drought, this project will provide a variety of ways for acequias to improve irrigation efficiency and help sustain the economic viability of farm operations. On a statewide level, irrigation accounts for approximately 75% of surface water use in New Mexico.
To introduce 140 acequia irrigators to water management concepts and technologies through the placement of seven demonstration projects in separate geographic areas of San Miguel County.
To increase water management knowledge by providing bilingual educational materials to 640 irrigators at acequia meetings and other activities by the end of the second year.
To increase knowledge of water management through the presentation of a bilingual video to local irrigators.
Develop specific long- term water management implementation goals, follow up survey and discussion with 640 irrigators participating in educational programs by the end of the second year.
Implement water management improvements with 32 landowners by enrolling them in the Interstate Stream Commission re-loan program by the end of the second year.
As previously mentioned, it is estimated that irrigation accounts for 75% of water use in New Mexico. Here in our Conservation District, which takes in most of San Miguel County, irrigation takes place on two major river systems, the Pecos and Gallinas along with several smaller tributaries. Water from these sources is generally used in a supplemental form to the rain fall we receive. New Mexico water law states that water from these streams must be used in accordance to priority dates. This means that irrigation systems(acequias or ditches) that have the oldest use dates get to use the water first. In most cases, systems above get the water first. Lives have been lost and feuds between neighbors and family members are a part of the history of irrigation here. The major problem is to get a limited resource such as water to all the water users on a stream system that have irrigable land and who have the right to use it.
Acequias were generally the first thing built when a community was established and for the most part remain in the same places and conditions. The diversion dams were made by stacking rock and brush across the stream. Many of these structures are still in place and when flood conditions exist, they get damaged or destroyed. In most cases the Acequia ditch was designed and built so that any unused water flowed back into the stream above the next diversion dam to provide more water to be diverted.
Much of the water diverted is lost (37% NM State Engineer Office[SEO])in conveyance losses through seepage, vegetation growth and evaporation getting to the farm head gate.
Water losses on the farm can be attributed to unlined ditches, the farm is not designed properly, poor maintenance and the absence of measuring devices. Other variables on the fields can also cause problems with efficient water use i.e., soil intake rate or how fast it lets the water soak in, the amount of water the soil can absorb and if the soil erodes easily or not. The manner in which water is applied to the field affects irrigation efficiency. In our area most irrigators flood irrigate. This is the simplest form and is accomplished by opening the head gate on the acequia and directing the water over the field. If the field is smooth and relatively level, the water will reach most areas and wet the soil adequately for the crop. Some fields have corrugations or furrows made across the field to help distribute the water more evenly. When fields are flood irrigated the relation between the slope, distance, soil type, and flow rate must all be considered for a proper watering that has little water passing the root zone and or runs off the end of the field past the crop. An irrigator may have the correct flow for a particular slope, but the length or distance down the field is too long for the soil type. The traditional farmer here has a field much longer than it is wide. This usually causes difficulties in getting the water to the end without over watering the upper portion of the field. Besides length of field, steep slopes and uneven surfaces are other major problems preventing an efficient irrigation.
We initially selected six participants, a seventh was selected later. We then surveyed the elevations of each irrigation turnout site, had a design drawn up, and constructed the new turnout to the specifications of the Natural Resources Conservation Service(NRCS). Three of the six irrigation turnouts were constructed during the off season of 1999 and four more built in the fall and winter of 99 and 2000.
The new turnouts provided the participants with greater control of the water onto their fields. In two cases pipes were installed and attached to splitter boxes at the field’s edge to help slow the water’s energy dropping from the ditch level to the field. This prevents the water from eroding the field when it enters and allows the irrigator to have control the directional flow of the water also. In the case of Cathy Swedlund, the new turnout and piping allowed her to get water around the edge of a deep ditch or arroyo to land she was unable to irrigate since she purchased her land. This was 20 acres of alfalfa and grass crop. For Daniel Garcia the structure we made provided him the ability to check the water in the irrigation ditch, backing it up to a level high enough to then flow onto an area of his field that is difficult to get water to. The structure consisted of two walls with a floor across the bottom of the acequia ditch that prevented the water from under cutting or eroding under the ends of the walls as it flowed over the check boards across the ditch. The previous structure had failed and collapsed because it had no floor.
We used soil moisture sensor blocks manufactured by the Irrometor Co. to assist us in determining the soil’s moisture content and to help us to determine over what period the moisture is being reduced to the 50% range. These sensor blocks(approx. $20 each) have two electrodes encased in gypsum with a perforated stainless steel cover. A meter(cost in $200 range) is attached to the block to get a reading that shows the electrical resistance between the soil and the moisture attached to it. The drier the soil, the higher the number. When the soil gets to a certain point of dryness, a plant will no longer be able to extract moisture from it. We encourage irrigating before the soil’s moisture drops below the 50% level. Likewise we try to avoid coming back with an irrigation too soon when the soil still has a high percentage of moisture. This is critical for saving water and for good production on certain crops grown. E.g. when over watered, alfalfa will die out due to a lack of oxygen and grasses will begin to take over the field.
These blocks are very durable and we are able to use them from year to year. In our work they have shown that although it has rained and the top portion of soil, (6” level) is wet, the lower portion can still be dry and the farmer should still consider scheduling an irrigation. They have also shown that one part of a field may have received enough water while another section of the same field could use more. The use of the moisture sensors were primarily used to give us something to compare and gage the irrigation times with. As can be seen with the graft on Henry Sena, his soil was kept fairly moist as he had to keep the soil moist so his new crop could sprout and establish a root system.
Since the cost of sensors and a meter is prohibitive for most of our local irrigators, I instructed participants on using the “Feel and Appearance Method” of determining the soil’s moisture. This is based on a booklet produced by the USDA’s Natural Resources Conservation Service(NRCS). Basically you dig a sample of the soil from the depth you are concerned with, try to form a ball with it and examine the appearance it makes on your hand. With a little experience, an individual can get within 5% of the moisture content. This method is demonstrated on the educational video produced for this project, titled, ”Acequia irrigation in San Miguel County”.
Water savings go hand in hand with good distribution systems. If the farmer is unable to get the water distributed over the field evenly, than the efficiency will suffer and water savings will be limited. The fields our participants are farming are not leveled and have problems with slope, length of run, gophers, and a lack of head pressure or water supply. To over come some of these obstacles we encourage them to use the following methods.
Corrugations across uneven fields improves water distribution for closely seeded crops like legumes and grasses. Several of our participants use these, while others had them when the field was initially planted, but since have filled in due to irrigation and farming activity over time. In most cases these corrugations are not re-established until the field is replanted. The NRCS generally puts this irrigation method at about 30% efficiency. The other 70% is tied up evaporation, deep percolation, undesirable plant use, or in the form of tail water that passes the end of the field.
Gated Pipe Two of the participants are beginning to use simple forms of gated pipe systems. Justo Lucero and Gilbert Gallegos. The pipes carry the water across the ends of the field and have openings every 24 to 30 inches where the water spills into corrugations to then flow across the field. These systems help prevent conveyance losses getting the water to the plant. Fields with long runs or distances across the field generally require additional piping to carry the water further before it is put onto the ground using outlets to prevent water loss due to deep percolation. Both of these individual’s use gated pipe across the top end of the field and have no above ground or underground pipeline to have outlets cutting the length of runs. Each individual is at a various stage of system development and each system will vary as for as it’s design and cost. Besides being slightly more efficient than just having simple corrugations, they are generally more convenient and labor saving. Additionally, where the conveyance pipe is used, there is a reduction or elimination of vegetative growth that hinders flow and consumes some of the water.
To impact the future of local irrigation and provide the opportunity for sustainable agriculture we as an agency must continue to provide educational activities along with other incentives that sells our irrigators on the benefits that can be gained through these improvements and managing their irrigation closer. We must continue partnering with other agencies i.e. NRCS, SEO, County Extension Agent, and other interested parties. To just tell an irrigator he runs the water too long and he should change his ways will not garner their interest. Through some of our tours to local farmers fields that are being successful, irrigators witness possible applications to their own situation. Our video and educational materials provide them ideas and facts to reinforce the benefits possible. We always hear from the participants that seeing other operations impresses them most. They want to see other sites. Some are animated to initiate similar practices on their land.
Education and Outreach
2002 summary of Survey of Acequia users
Corriente News Letter
Video, “Acequia Irrigation in San Miguel County” English and Spanish
Pamphlet, “Determining the best time to irrigate”
Year 2000, Acequia Conservation Plan for San Miguel County
Presentations were made in:
Mora and Las Vegas, NM with approximately 100 attending. Teachers, students and local producers were present to hear of our involvement with acequia users. Along with conservation issues, we discussed cultural and traditional values that should be passed on to the youth of our communities.
Another presentation was made in Oñate New Mexico to farmers of the area. We viewed the Video and discussed different aspects of how one can work toward improving their irrigation efficiency.
Tours held in 2001 and 2002 in the El Pueblo, Villanueva area with more than 25 attending. At these, we viewed 5 to 6 different individual fields that provided a alternative method of irrigation and crop involved. These events provided an excellent forum to see and discuss various facets of irrigation farming. We received a lot of positive feed back at these.
Meetings were held in Las Vegas, Pecos and El Pueblo areas with 50 plus attendees. At these we invited guests i.e. County Extension Agent, Local NRCS Conservationist, Acequia Liaison with the Office of the State Engineer, New Farms Cooperative, and The Santa Fe Farmers Market. Some 30 acequias were represented at the tours and meetings.
We tried different schedules and presentation angles to encourage attendance at these activities but, still conflicts existed with farmers primary income work schedules. Weekends proved no better as other chores and family events generally take priority. Unfortunately many parcels belong to absentee landowners who live 1 to 3 hours away.
Other meetings were held with individual acequia mayordomos(ditch riders) and parciantes(irrigators) to discuss problems, assistance programs available and to distribute educational material.
Education and Outreach Outcomes
Areas needing additional study
Areas needing more study:
Comparison studies on different methods of irrigating at our local level e.g. Drip Irrigation, Sprinkler, and gated pipe vs. traditional methods of flooding the fields. Which system would be practical for the irrigator. What are the costs of installation, operation and what are the real returns? In another conservation district close by, they are installing a sub-surface drip system in an alfalfa field with the water supplied from a well. The cost will run around $1000 per acre(to be cost shared through EQUIP). I was told that it was more reasonable after 50 acres. When people are paying for the water used, they tend to look closer at drip or sprinkler systems as water saved is money saved. Whereas the open ditch or acequia user, looks at gated pipe systems more closely. Its more affordable and simpler to use and maintain. Even though some of our users are beginning to adapt drip or sprinkler in a limited way, having these comparisons and experience could help educate and convince them of the advantages and disadvantages of one system over another.
Alternative crops that can help sustain our local small farmer
Assistance in developing markets for local production
Green House production to off set the short growing season