The cache is not at the posted coords. You need to solve the following puzzle to reveal the actual coords. This cache actually has nothing to do with irrigation - a super-duper security guard stole the one that was there, so I had to choose a new hiding spot.
N38 27.ABC W121 29.DEF
A, B, C, D= By 2012, the area of irrigated land had increased to an estimated total of 3,242,C1A km2 (8B1 million acres), which is nearly the size of India. The irrigation of 20% of farming land accounts for the production of D0% of food production.
E= Guns are similar to rotors, except that they generally operate at very high pressures of 2E5 to 900 kPa (40 to 130 psi) and flows of 3 to 76 L/s (50 to 1200 US gal/min), usually with nozzle diameters in the range of 10 to 50 mm (0.5 to 1.9 in).
F= Irrigated land in the United States increased from 300,000 acres in 18F0 to 4.1 million in 1890, then to 7.3 million in 1900. Two thirds of this irrigation sources from groundwater or small ponds and reservoirs, while the other one third comes from large dams.