SACRAMENTO (CBS/AP) — Regulators are ordering farmers with California’s oldest water rights to stop pumping from the San Joaquin River watershed for the first time in memory.

“We’re in the Delta. So, we’ve never had a situation where we’ve had a lack of water,” wheat farmer Paul Marchini said.

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State water board engineer Kathy Mrowka told a public drought hearing that the curtailment orders will be sent to so-called senior rights holders on Friday.

The mandatory conservation orders for rights holders with century-old claims to rivers and streams will be the first anywhere in the state since the 1970s. They would be the first in memory to senior water-rights holders along the San Joaquin River.

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“They have the big stick is what it amounts to,” Marchini said.

California officials already have ordered conservation for cities and towns and some other farmers. Friday’s order is the start of expected across-the-board cuts for the state’s most senior rights holders.

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