(CNN) The Golden State could soon refer to the hue of California's lawns.

Gov. Jerry Brown on Wednesday imposed mandatory water restrictions for the first time on residents, businesses and farms, ordering cities and towns in the drought-ravaged state to reduce usage by 25%.

"We're in a new era," Brown said. "The idea of your nice little green grass getting lots of water every day, that's going to be a thing of the past."

The 25% cut in usage amounts to roughly 1.5 million acre-feet of water (an acre foot of water equals about 325,000 gallons) over the next nine months, state officials said.

"This historic drought demands unprecedented action," Brown said, standing on a patch of dry, brown grass in the Sierra Nevada mountains that is usually blanketed by up to 5 feet of snow.

The reduction in water use does not apply to the agriculture industry, except for the requirement that it report more information on its groundwater use. The exclusion prompted some criticism, as agriculture uses about 80% of California's developed water supply.

Farms in the state have taken a hit, with reduced water allocations and thousands of farmworkers laid off. But climate writer Eric Holthaus of Slate wrote that "wasteful agriculture is literally sucking California dry."

Photos: California's historic drought Photos: California's historic drought Inmates at a state prison in Vacaville, California, install a drought-tolerant garden in October. The garden will be watered using reclaimed water from the prison's kitchen. California is entering its fifth year of severe drought. Hide Caption 1 of 28 Photos: California's historic drought California State Assemblyman Devon Mathis speaks to members of the media after he helped secure a donation of 100,000 water bottles in September. More than 300 homes in Porterville, California, were out of running water because of dried-up wells. Hide Caption 2 of 28 Photos: California's historic drought Evacuee James Logan embraces his wife, Lisa, as they listen to an update about a wildfire in Clearlake Oakes, California, in August. Drought conditions have fueled numerous wildfires across the state. Hide Caption 3 of 28 Photos: California's historic drought Firefighters hike down a hill in Clearlake, California, as they mop up hot spots from the Rocky Fire in August. Hide Caption 4 of 28 Photos: California's historic drought A golfer in San Francisco hits a shot in July. After Gov. Jerry Brown ordered a statewide water-use reduction of 25%, golf courses have been struggling to keep their fairways and greens watered. Hide Caption 5 of 28 Photos: California's historic drought People picnic in July on the sandy bottom of Mirror Lake, which is normally covered with water at Yosemite National Park. Hide Caption 6 of 28 Photos: California's historic drought A man applies green paint to a brown lawn in Novato, California, in May. Hide Caption 7 of 28 Photos: California's historic drought A close-up of the dry Guadalupe Creek, as seen in San Jose, California, in April. Hide Caption 8 of 28 Photos: California's historic drought Workers install artificial grass at a home in Burlingame, California, in April. Hide Caption 9 of 28 Photos: California's historic drought Motorists in Rancho Cordova, California, pass a sign in April reminding them to reduce water use. Hide Caption 10 of 28 Photos: California's historic drought A woman in Sequoia National Park looks up at barren terrain typically populated by skiers in April. Hide Caption 11 of 28 Photos: California's historic drought California Gov. Jerry Brown, right, walks with Frank Gehrke, chief of the California Cooperative Snow Surveys Program for the Department of Water Resources, near Echo Summit, California, in April. Gehrke said this was the first time since he has been conducting the survey that he found no snow at that location at that time of the year. Hide Caption 12 of 28 Photos: California's historic drought People hike along a ridge overlooking the Griffith Observatory, where vegetation was drying out in Los Angeles in March 2015. Hide Caption 13 of 28 Photos: California's historic drought In March 2015, a power boat sits on a Lake McClure parking lot that used to be underwater in La Grange, California. Hide Caption 14 of 28 Photos: California's historic drought Low water is seen at the dam of Lake Success, near East Porterville, California, in February 2015. Hide Caption 15 of 28 Photos: California's historic drought This picture taken from a helicopter shows a drought-affected area near Los Altos Hills, California, in July 2014. Hide Caption 16 of 28 Photos: California's historic drought A woman walks her dog in San Francisco in July 2014. Hide Caption 17 of 28 Photos: California's historic drought A worker washes the sidewalk in front of a San Francisco hotel in July 2014. Hide Caption 18 of 28 Photos: California's historic drought In June 2014, a pedestrian walks by a sign posted in front of the lawn at the California State Capitol in Sacramento. Hide Caption 19 of 28 Photos: California's historic drought Residents photograph the burning ruins of their home, which was destroyed in a wildfire in Carlsbad, California, in May 2014. Hide Caption 20 of 28 Photos: California's historic drought Volunteers pack bags of oatmeal at a San Francisco food bank in May 2014. The longstanding drought has contributed to an increase in food prices. Hide Caption 21 of 28 Photos: California's historic drought Fingerling Chinook salmon are dumped into a holding pen as they are transferred from a truck into the Sacramento River in March 2014. Low water levels forced wildlife officials to truck more than 400,000 fish nearly 300 miles. They usually make the trip on their own. Hide Caption 22 of 28 Photos: California's historic drought A tractor plows a field in Firebaugh, California, in February 2014. Almond farmer Barry Baker had 1,000 acres -- 20% -- of his almond trees removed because he didn't have access to enough water to keep them alive. Hide Caption 23 of 28 Photos: California's historic drought Plumbing technician Todd Snider installs an aerator at a home in Novato in February 2014. Californians have been installing water-saving devices in their homes to reduce consumption. Hide Caption 24 of 28 Photos: California's historic drought A worker installs an artificial lawn in front of an apartment building in San Jose in January 2014. Hide Caption 25 of 28 Photos: California's historic drought A car sits at the bottom of the Almaden Reservoir in San Jose in January 2014. Hide Caption 26 of 28 Photos: California's historic drought Rocky shores are exposed by the low waters of Morris Reservoir, on the San Gabriel River near Azusa, California, in January 2014. Hide Caption 27 of 28 Photos: California's historic drought During a news conference in San Francisco in January 2014, Gov. Jerry Brown holds a chart showing the statewide average precipitation. The governor declared a drought emergency for the state, saying it faced "perhaps the worst drought that California has ever seen since records (began) about 100 years ago." Hide Caption 28 of 28

The action comes as the Sierra Nevada snowpack, which Californians rely on heavily during the summer for their water needs, is near a record low.

One famed golf course group said it should be able to keep its fairways and greens green.

David Stivers, an executive vice president of the Pebble Beach company, said his company is studying the restrictions to see what effect it will have on business.

"It will not affect our golf course irrigation because we use recycled waste water (for golf course irrigation) from a plant we built in 1994," he said. The company operates Pebble Beach Golf Links, Spyglass Hill Golf Course and The Links at Spanish Bay as well as three hotels.

He said the drought has yet to hurt revenue.

"People up here are also very conscious about water usage and the expense of water in this area," he said.

Pepperdine University in Malibu, known for its beautiful campus, said it would be challenging to meet the restrictions given the water-saving practices already in effect. The school already uses recycled and reclaimed water for campus irrigation and now it has turned off all fountains on campus, according to Rhiannon Bailard, director of the university's Center for Sustainability. The university was also encouraging students to further reduce water usage.

A new way of managing a precious resource

In addition, Brown's executive order will:

• Impose significant cuts in water use on campuses, golf courses, cemeteries and other large landscapes.

• Replace 50 million square feet of lawns throughout the state with "drought-tolerant landscaping."

• Create a temporary, statewide consumer rebate program to replace old appliances with water efficient models.

• Prohibit new homes and developments from irrigating with potable water unless water-efficient drip irrigation systems are used.

• Ban watering of ornamental grass on public street medians.

• Require agricultural water users to report more water use information to state regulators, increasing the state's ability to enforce against illegal diversions and waste.

"It's a different world," Brown said Wednesday. "We have to act differently."

The estimate is based on NASA satellite data analysis of how much water the state's reserves lack. That's more than 14,000 times the amount of water it would take to fill the Dallas Cowboys stadium, according to CNN calculations. It's the amount of water that flows over Niagara Falls in about 170 days' time.

The entire state faces at least a moderate drought, and more than half of the state faces the worst category of dryness, called an exceptional drought, according to the U.S. Drought Monitor.

California isn't the only state feeling an absence of rain. As of late September, 30% of the Lower 48 faced at least a moderate drought, particularly in the Southwest states neighboring California and in Texas, the Drought Monitor says.

But none of those states is facing the extremes of California, where the drought has been a slowly building natural disaster since 2012.

In fact, Brown last year declared a state emergency, saying his constituents are facing "perhaps the worst drought that California has ever seen since records (began) about 100 years ago."

What's been done

On September 16, Brown signed "historic legislation" that created "a framework for sustainable, local groundwater management for the first time in California history," the governor's office said. Before the new legislation, California was the only Western state that didn't manage its groundwater, officials said.

Last month, Brown unveiled an emergency $1 billion spending plan to tackle the state's historic drought.

According to the State Water Resources Control Board, the package will specifically accelerate $128 million from the governor's budget to provide direct assistance to workers and affected communities.

Proposition 1 funding, which enacted the Water Quality, Supply, and Infrastructure Improvement Act of 2014, will funnel $272 million into safe drinking water efforts and maintenance of water recycling infrastructure. Some $660 million from Prop 1 will also be accelerated for flood protection in urban and rural areas.

As part of the changes, Brown said additional measures will crack down on water inefficiency as California enters the fourth year of a worsening water crisis.

The March snowpack measurement came in at 0.9 inches of water content in the snow, just 5% of the March 3 historical average for the measurement site.

The overall water content for the Northern Sierra snowpack came in at 4.4 inches, just 16% of average for the date. Central and southern Sierra readings were 5.5 inches (20% of average) and 5 inches (22% of average) respectively.

Only in 1991 has the water content of the snow been lower.