WSPC12621 - Laserfiche WebLink

Home Browse Search

0002 7 5_~__, RESPONSE TO QUESTIONS FROM LIVING RIVERS OF SCOTTSDALE, ARIZONA REGARDING PROPOSAL FOR IMPROVING DRAINAGE OPERATIONS IN THE YUMA VALLEY Question 1: How Does water six feet below the surface impact vegetable, cotton, wheat, and alfalfa crops? Answer: The goal is to achieve groundwater depths of 6 feet or greater throughout as much of . the Yuma Valley as possible. Although 6-foot depth to groundwater levels is generally acceptable, 8 - foot depth to groundwater levels are preferred when attainable. Surface soil horizons in the Yuma Valley contain high levels of clay. With high groundwater levels, the clay tends to absorb water beneath it through a process called capillary action. This rising water has a tendency to cause the soil to be saturated in the root zone for many crops including cotton, wheat and alfalfa. Without sufficient oxygen in the soil, the plants will be damaged and yields reduced. In addition, as the water rises by capillary action, it moves salt upward into the root zone, and jn some caSes to the ground surface. This again damages the plants and reduces yields. Citrus roots continuously submerged in water will rot and damage or kill the plant. In addition, irrigation under these conditions is more difficult. If too much water is applied the soil horizon will be saturated for some time, resulting in damage to crops. Having depths to groundwater greater than 6 feet also provides a safety zone in case drainage wells in the area fail. Water levels rise quickly without nearly continuous drainage pumping. The movement of a farm equipment such as a tractors or other farm equipment is also impacted by inadequacy of drainage. Wet soils cause lack of traction and often damage to fields from wheels digging into the soil. In addition the soil will tend to stick to the f~ equipment tires and form large clods which are thrown off the tire into the field. This makes the soil difficult. to work with and does not promote plant growth or the germination of a new crop. Question 2: Are there proposals for development of residential or commercial properties in the area in which the water levels would be lowered? If so, what/where are the proposed developments? Answer: There are currently at least two subdivisions in the Yuma Valley that are heavily impacted from groundwater. These are the Padre Ranchitos subdivision located in the valley along the escarpment of the mesa, and Hacienda Estates, located south of 24th street below the mesa. Wells near these subdivisions are operated nearly continuously to prevent damage from occurring in these subdivisions. For instance Hacienda Estates has experienced problems with roads and sidewalks collapsing, and mosquitoes have been a problem in this subdivision. In Padre Ranchitos, a subdivision that relies solely on septic systems for handling sewage, problems with septic sytems operating correctly has occurred.