TAMPA BAY, FL — Ongoing severe drought conditions are drying up one of the Tampa Bay area’s main water supplies, local rivers, officials said.

Tampa Bay Water, the region’s nonprofit wholesale water supplier, triggered a Stage 3 Extreme Regional Supply Shortage as of March 1 because of significant rainfall and river flow deficits, as well as projected low regional reservoir levels.

This escalation comes at a time when the Tampa Bay area is facing one of the most severe regional water supply shortages in the last 50 years, Tampa Bay Water said in a news release.

Water from rivers makes up more than 40 percent of the region’s drinking water supply, particularly the Alafia River, the agency said. Because of current drought conditions, river water isn’t being used as a water source.

“We are not taking anything from local rivers,” Warren Hogg, chief science officer for Tampa Bay Water, said, according to WUSF. “Flows are so low we can’t take any water for the region, for our system. All the water we use in our surface water plant now is from the regional reservoir.”

He continued, “We have water stored in our regional reservoir, which holds 15.5 billion gallons when full. It’s now dropped to 7, so we’re more than halfway into our savings account. We’ve got [three] months of the dry season to go.”

To meet water demands, Tampa Bay Water will rely on groundwater and seawater sources so that the region will have the drinking water it needs.

The announcement comes weeks after the Southwest Florida Water Management District placed new water restrictions on the Tampa Bay area and parts of central Florida under its Modified Phase II water shortage restrictions plan.

The region received below average rainfall during the summer rainy season, and, as of December, there was a 13-inch rainfall deficit compared to the historical average 12-month total, SWFWMD said.

SWFWMD water shortage restrictions, including once-a-week lawn watering, are in effect for the district through July 1. They apply to all of Citrus, DeSoto, Hardee, Hernando, Hillsborough, Manatee, Pasco, Pinellas, Polk, Sarasota and Sumter counties; portions of Charlotte, Highlands and Lake counties; the cities of Dunnellon and The Villages in Marion County; and the portion of Gasparilla Island in Charlotte County.

Tampa Bay Water said that a Stage 3 Extreme Water Supply Shortage happens when both the annual average river flow deficits exceed 10 million gallons per day, and the C.W. Bill Young Regional Reservoir is forecasted to be below 93 feet elevation within three months.

The average rainfall deficit over the past 12 months is 11.57 inches. Rainfall in February averaged 1.35 inches, 1.45 inches below normal, the nonprofit said.

Meanwhile, the C.W. Bill Young reservoir is currently storing 7.07 billion gallons, 45.6 percent of its 15.5-billion-gallon capacity.

Now, the agency is calling on those living in the region to take action.

“There are many opportunities to save water throughout the day; we all need to step up and make it a priority,” Hogg said. “Residents did this two years ago and helped greatly reduce water demands.”

As the Tampa Bay region heads into the driest months of the year, when both temperatures and water use increase, Tampa Bay Water is asking residents to step up and save water, offering the following tips for conservation:

Water your lawn no more than one day per week. Turn off the water when you brush your teeth.Wait until summer when it’s raining to plant or sod, as new plants and sod need a lot of water to establish.Fix household leaks. The four most common leaks to fix are broken sprinkler heads, leaking irrigation lines, leaky pipes or faucets, and leaking toilet flappers.Take no more than a five-minute shower.

Water-saving efforts will help extend the utility’s water supplies, the agency said.