Colombia- Multiple uses of water in the Cajamarca irrigation system

Colombia- Multiple uses of water in the Cajamarca irrigation system

TitleColombia- Multiple uses of water in the Cajamarca irrigation system
Publication TypeWeb Article
Year of PublicationSubmitted

This case study (in Spanish) analyses the use of irrigation and domestic water systems serving a rural community in the Valle del Cauca, Colombia.

Full Text

The villages of Cajamarca and San Isidro, located in the municipality of Roldanillo in the Cauca Valley of Colombia, are supplied with water from two systems. Both systems are gravity-fed piped water supplies that tap perennial mountain streams. One is primarily for irrigation, and supplies both villages. The other is primarily for domestic use, but only supplies Cajamarca. Both systems, however, are actually used for a combination of domestic and productive uses. They play a vital role in the livelihoods of the 700 people living in the two communities, which as a result, are relatively prosperous. The two systems are managed by the same community-based case studywater organization.

The aqueducto (the domestic system) was developed in two phases (1954 and 1995), both with the external financial investment of the government. The current system includes an intake about 5 km above the valley, a compact treatment plant, storage tank, a pvc piped network, and household connections for all the families in Cajamarca. San Isidro, a newer settlement at higher elevation, is not supplied by the system.

The compact treatment plant is probably not the ideal technology for this community, being costly and difficult to run and the operators have not been trained. As a result, the quality of water supplied by the system is poor. Most people however, express satisfaction with the water quality. Users of the irrigation system in San Isidro boil the water from this system when it is used for domestic purposes, and in fact, the users of the domestic system in Cajamarca may be putting themselves at more risk as they believe this water to be safer (and fewer boil it) when in fact it is not.

The irrigation system that serves both villages and nearly all households, constructed in 1996, is also a piped network with storage and connections (a single time) near the boundary of each farm plot. This system was also built with government investment. Sprinklers are used by most farmers to irrigate profitable horticultural crops like pepper, tomato, and cabbage, although recently some farmers have also adopted drip irrigation. Neither, the domestic nor irrigation system have meters at either household or system level.

Domestic water is supplied at a low, flat-rate tariff of US$2.4 per month. Given the high average rates of consumption (370 liters per person per day when calculated at the treatment plant, however, loses may well be half of this amount and are unknown), this is equivalent to a cost per m3 of US$0.04. Irrigation water is charged according to the size of plot, type of use (including livestock and fishponds) and economic status with an median charge of about US$2.9 which is equivalent to about 0.0043 US$/m3 (based on the average available supply from the system before loses, which again are likely to be large, of 22m3/household/day). Most users believe the tariffs to be fair and affordable, and the default rate on the combined quarterly bills for both systems is low. Users find it easier to pay the quarterly bills matching cycles of their income from irrigated crops. The income from these tariffs is sufficient to cover the operation (including full-time operators for each system, who in practice work together) and maintenance costs, including chemicals for the inefficient treatment plant. Some money is also invested in tree-planting to protect the water supply catchment.

The villages are fortunate to be supplied by two reliable perennial streams, and the communities have undertaken active measures to protect the catchment including planting trees and constructing fences to exclude livestock and prevent stream bank erosion. These catchment protection measures are programmed by the water organization, and are a locally - based initiative rather than being undertaken for the environmental authority which also requires such actions. There are rules that everyone should participate in catchment protection works. People believe that this has led to increased streamflow, and ensured availability of water for the systems. Most catchment protection measures have been undertaken in the catchment of the irrigation system, due to the non-cooperation of the owner of most of the land that forms the other catchment of the domestic system. Further measures taken to conserve water resources include control of irrigation techniques. Farmers are not allowed to use furrow or flood irrigation methods and must use sprinklers or drip to improve irrigation water use efficiency. In summer, access to irrigation water is limited to turns every 3 days.

A single community-managed organization (Asodisriego) now runs both the water supply systems. Originally this organization was just for the irrigation system, but when the domestic system encountered management problems in 1995, the community asked Asodisriego to manage both systems. The same community leaders have been involved in running this organization since mid 1990s, which is both a strength and a weakness. These leaders have developed a strong management capacity, including the ability to make and use linkages at the municipal and department level to secure resources and influence. However, it leaves the system vulnerable to the loss of a few key individuals and thus, potentially compromising future sustainability.

Community members do participate in activities such as catchment protection and in meetings where they are kept informed, however, decision making is in the hands of a few leaders. As they have managed the systems well, most people are satisfied with this situation. Strong leadership has been critical. Despite not having a legal basis for such multiple-use water supply systems and no external support beyond occasional investment in infrastructure, the community have been able to develop their own vision and mode of operation for the systems because of good leadership and trust of the community.

The two water supply systems have some common characteristics. Both supply relatively large volumes of water at low cost. As well as meeting domestic water demands, this has enabled the residents of Cajamarca and San Isidro to develop a thriving agricultural basis to their livelihoods. As well as 99% of the residents being engaged in irrigated agriculture that generates 3 or 4 crops and associated income a year, many are involved in livestock production. Livestock, including raising cows and pigs, are seen as a source of additional income and also savings. Smaller livestock, especially chickens, are common. In Cajamarca, where people have access to both water systems, most people use the domestic system for their livestock because it provides water closer to home where livestock are kept, and because of the perceived better quality. Incomes are very variable, but families may earn between US$80 and 1200 from their cultivation activities alone.

The multiple use water systems in Cajamarca and San Isidro have played a vital role in improving the livelihoods of the residents. Previously they used to grow less water intensive but less lucrative crops like tobacco that were harvested once a year, whereas now they are able to engage securely in year-round irrigation and livestock production. This has helped reduce migration from the village, increase the value of land, and reduce conflicts over previously much scarcer water resources.

The full report is available in Spanish.