The precipitation data of the El Alto, Tambillo and Comanche stations are homogenous and consistent. The meteorological data from Irpa Chico, Collana and Viacha are consistent, but heterogeneous. The monthly precipitation in Viacha in December, January, March and April are better examples of a normal distribution in comparison to the months of October, November and February. The average annual precipitation in Viacha, in a thirty-four year time period, is 559 mm. Some 76% of this precipitation occurs in November to March. The minimum precipitation in Viacha, with an 80% probability of absence for the vegetative period, from October to April is 269mm. January is the month with the most precipitation (75 mm). The estimated potential of evaporation-transpiration with the Penmen-Monteith method is 1,168 mm a year. October constitutes the month with the greatest value of ETP (116mm). The maximum volume of food storage in the Calacalani Lagoon is 137,000 m3, with annual losses of 48,218 m3. 82% of these losses are due to evaporation and 18% due to infiltration. The usable water volume, taking into account the conservation of 30% of the total volume in order to maintain the aquatic fauna and flora, is 47,740 m3. With some exceptions, the quality of the water is suitable for livestock consumption and with an estimated irrigation capacity of 7-11 hectares per year. The Jacha Jahuira River- Pallina transports an average volume of 38.5x106 m3 annually. This presents serious restrictions for water use in agricultural irrigation and human consumption. The use of the River's water for agricultural purposes has been conditioned for special handling operations, which can reach an irrigational surface of 5,199-8,665 hectares/year. The ground water level may vary from 3,867-3,843 m over that of the ocean level. This presents a fluctuation of 1.2 m in the deep valley receptors of the Letanias hill country and 0.1 m in the community presented an average flow of 0.13 l/s, which represents a volume of 4,100 m3/year. The artesian or subterranean water represents an interesting potential for its quality as well as its availability of 788,000 m3/year of volume. With 12 hours of daily pumping of this water, some 53-88 hectares/year are suitable for irrigation. This is in spite of the fact that the lack of infrastructure has provoked the abandonment of deeply excavated wells, estimating an annual lose of 145,00 m3. Artesian water has no restriction in quality, for animal and human consumption or for irrigation purposes. Some ground water wells have been restricted for human use, due to bacterial contamination. The Choquenaira Community is located in the middle valley of the Jacha Jahuira-Pallina. In the high valley the reduction of vegetation coverage is being observed, that when combined with seasonal rains, provokes water erosion and the transportation of sediment through drainage; Estimating an average transportation of 104 TM of sediments in suspension, especially during the rainy seasons (December-March). In the lower valley severe biological contamination (for human consumption) has been detected. This is due to the discharge of service water from the Viacha City sewer system and the Laja population; and so the sediment accumulation, increasing the risk of overflow and flooding. Extreme events, such as flooding that exceed 50 million m3 of annual drainage, have happened four times in 52 years; which is approximately every 13 years. There is an annual 76% probability that a major event will not occur. The micro-region of the Choquenaria covers a total area of 2,126 hectares. Some 12% (262 hectares) are covered with pastures in a humid environment and temporarily or permanently flooded areas (bofedales, and fertile plains); 19% (401 hectares) are covered steeps, shrubs, and rocky outcrops with strong inclines; 69% (1,463 hectares) correspond to dry land cultivations, pastures, and or bushes that lack distinction. The highest quality springs are used for human consumption, which is estimated to be 10 liters/inhabitant/day, representing an overall community consumption of 594 m3/year (148 inhabitants). This level of consumption is low in comparison to that of the Bolivian, 30-50 l/habitant/day, which is due to the difficulty in accessing the water source. With an average cattle possession in a family being five bovines and 40 ovine, the average consumption is from 450 l/possession/day. This represents an annual consumption of 10,374 m3 used for livestock water in the Choquenaira Community. The surface that undergoes irrigation in the winter does not exceed 600 m2, which is a surface that needs 440 m3/year. The requirement or unitary demand for a cultivation system, consisting of barley (57%), potato (28.6%), and alfalfa (14.4%) in the Choquenaira Community is about 4,443 m3/hectares/year, assuming an irrigation efficiency of 100% and 7,405 m3/hectares/year with a 60% efficiency using a surface irrigation system. The inhabitants of the community use an operational strategy of national resources (ground, water, cultivations, etc.) on the basis of availability and incidence of climatic resources, with the use of local ecological indicators to predict the climate. The commoners seek the reduction of agricultural risk, through specialization in hydric cultivation (dry farming) crops, the spatial operations (epochs), water conservation (water gathering) and the diversification of fountains/springs. There are oftentimes-distinct gender roles in the community. Agriculture is considered a productive activity, in which men play the dominant role. Whereas the women play a fundamental role in obtaining water, especially that which is used in human and animal consumption. The overall offering of the local hydraulic system, composed of the contribution of the Jacha Jahuira River, Calacalani Lagoon, the ground water, and artesian wells, is 39.3 million meters cubed per year. The actual demand of the community, that includes human and animal consumption as well as the irrigation in winter pastures, reaches 11,381m3/year. The potential demand, that includes both human and animal consumption, irrigation in winter pastures and the supplementary irrigation of dry farming, reaches 3.2 million meters cubed per year. The local hydraulic system offers volumes of water, sufficient enough to meet the community's actual and potential demand. However, its contamination and difficulty to access has caused the inhabitants to develop spatial and temporary strategies in order to access the water. The commoners consider the developments of these hydric resources, especially that of human consumption, as a short and long term necessity.