State officials said they intended to adopt a final order by the beginning of May, with enforcement — which includes fines of up to $10,000 a day — kicking in by the middle of July. The rush reflects an attempt to put the new rules into place as California moves into the summer, with high consumption driven in large part by outdoor watering.

“We need to act with urgency now or it will be too late to save the bigger chunks of water we need to save,” said Felicia Marcus, the head of the board. The latest draft reflects an attempt by the board to incorporate the response contained in those comments, which came from water companies, communities, businesses and residents. Local water agencies asserted that the state had failed to credit their conservation efforts; that it had not taken into account the particular demands of various communities, such as high industrial users or business agriculture; and that the four-tier system was too strict and confining.

The 25 percent cut does not apply to agriculture, which accounts for 80 percent of water use in the state. Under the new regulations, urban communities that provide more than 20 percent of their water to agriculture businesses, which had complained about the rules, will be able to ask the state not to count that water in computing how much they need to save, presumably pushing them into one of the lower conservation tiers.

Leaders of the board, who have come under fire in recent weeks for putting so much attention on urban users, defended that exemption, noting that farms had already experienced deep cuts in their water supply and were likely to be hit again in the months ahead.