Great Plains and Prairies

Like the Praries Holllister is flat in some places, for example where we grow all of our crops, however much of Hollister consists of rolling hills. Unlike the Great Plains and Prairies Hollister does not have severe weather conditions. Since it is a lot of farmland and irrigation, the weather has to be able to sustain the different crops year round.  Hollister gets an average amount of rain per year, and has average temperatures the rest of the year, with the exception of extremely hot days.
  So if it only rains an average amount each year how does Hollister supply more than 40 crops??
Hollister gets its water from San Benito County water district which works with the CVP or central valley project. The water is brought from way up Northern California through the aqueduct and delivered into the closest reservoir which is the San Luis Reservoir from there the water is pumped through a 5 mile tunnel and delivered to Casa de Fruita which is just outside of Hollister.
site:  http://www.sbcwd.com/