The grasslands that support cattle have dried up, farmers are struggling with diminished crop water and last year capped California's driest four year period in history with record low rainfall and snow. But Donald Trump nonetheless told voters in the state that there was "no drought" as he promised to solve their water crisis.

Accusing state officials of denying water to Central Valley farmers so they can send it out to sea to "protect a certain kind of three-inch fish" he promised the crowd in Fresno that they were "going to solve your water problem". Calling the problem "insane" Trump appeared to be referring to disputes about water that runs from the Sacramento River to the San Francisco Bay and out into the ocean. Some farmers claim more of it should be captured and diverted to them.

Trump who heard complaints from around 50 farmers before the rally told the rally of several thousand: "They don't understand — nobody understands it," he said, declaring at one point: "There is no drought. They turn the water out into the ocean."

Longstanding federal laws protect endangered species and fish, including the three-inch delta smelt. The native California fish on the brink of extinction has become in symbol in the battles over water distribution and environmental laws.

Water authorities claim they cannot divert the water because of the rights of upstream farmers and the minimum water allowances needed for the endangered species and wildlife in general. Seeking to overturn those laws the farm lobby, in the US's number one agriculture producer, is also calling for federal and state approval for new water tunnels, dams and other projects that would cost billions of dollars.

Promising to put their interests first if he was elected, Trump told the crowd that is he won, he would "start opening up the water so that you can have your farmers survive".

He also attacked Democratic frontrunner Hillary Clinton and claimed he was being "railroaded by the legal system", as he referred to an ongoing lawsuit against his now-defunct Trump University.