Lake Travis is only a few inches from being at its third lowest level on record.

On Monday the lake was at 636.65 feet -- less than a foot from the 636.58 feet it was in October 1984, the third lowest recorded level.

The lake's all time low came during what's called the drought of record, when the lake dropped to 614.18 feet in 1951.

With no end to the drought in sight, the Lower Colorado River Authority is preparing to ask customers to impose mandatory water restrictions within the next few weeks.

When the combined levels of Lake Travis and Buchanan reach 900,000-acre feet, down from the current 940,000-acre feet, the LCRA will ask so-called firm customers such as cities and industries to impose mandatory water restrictions on users.

"We're likely to see that, if these drought conditions continue, in the next couple of weeks or so," said Mark Jordan, who heads the LCRA's river management. "This has been a very serious drought."

At the 900,000 acre feet level, the LCRA will be requesting mandatory restrictions from customers. If the lakes fall to a combined 600,000 acre feet, the LCRA will case its interruptible supply of water and begin curtailment of its firm supply.

The drought has already triggered three water restriction measures.

When the combined waters of Lake Travis and Buchanan fell to 94 percent of capacity (or 1.897 million acre feet), the LCRA cut what's called "interruptible" water supplies to customers other than four major downstream irrigation operations.

The LCRA has also curtailed releases to bays and estuaries, and has reduced releases for instream flows.

"The goal is to make sure the critical needs of cities and industries, the firm water supply, is still there," Jordan says.

The sole remaining public boat ramp on Lake Travis remained open Monday, but was preparing to close when the lake drops to about 635 feet.

Still, there is plenty of the water in the lake for boaters to enjoy.

"For August and the fact that we're down about 30 feet, it looks very inviting," said Rich Ritzema, a boat sales consultant for Sail & Ski Center who was helping a new owner launch his boat Monday. "You just have to use a little bit of extra caution."

He says the lakescape can be deceiving, because it appears the lake is drying up. Instead, he says the lake is still deep enough to offer plenty of places for boating.

"Sure, the lake's a bit low, but it's still awesome to be out on a boat this time of year," he said.