Just how much water has flowed through Central Texas since the torrential storms a week ago?

Consider that the amount of floodwaters the past seven days could cover the entire City of Austin to a depth of four feet — enough to create the world's largest swimming pool.

Here are the details of how much water has flowed through the Highland Lakes and stored in Lake Travis since June 27:

• About 300,000 acre-feet of water passed through the Highland Lakes into the river below Austin. (An acre foot is how much water it takes to cover an acre. One acre foot is the same as about 326,000 gallons.)
• 400,000 acre-feet has been stored in Lake Travis.
• Total inflows: 700,000 acre-feet.
• The City of Austin covers 272 square miles. One square mile equals 640 acres, so the city proper covers about 174,000 acres.
• Thus: the amount of water that has come into the system, 700,000 acre-feet, is roughly equal to four feet of water covering the entire City of Austin.

How much rainfall have we had?
For many locations across Central Texas, the first six months of this year have been among the top 10 wettest starts to any year on record.

• At Austin-Bergstrom International Airport, rainfall of 31.71 inches through June 30 is the wettest start to any year, dating back to 1943.
• At Austin's Camp Mabry, rainfall of 27.68 inches is the 12th wettest start to any year dating back to 1856.
• At San Antonio, rainfall of 26.08 inches is the 7th wettest start to any year dating back to 1871.
• Year to date, rainfall across most of the Hill Country has measured between 25 and 30 inches. That is 12 to 16 inches above normal for this time of year for most locations. But several locations are very close to their average annual totals for an entire year — and the year is only half over.
• Many counties in the heart of the Texas Hill Country — Blanco, Brown, Burnet, Gillespie, Llano, Mason, Mills and San Saba — have received more than 35 inches of rain so far this year, according to LCRA meteorologist Bob Rose. Average annual rainfall in this region is about 28 to 32 inches.