Lubbock's main water supply dropped to historic lows yesterday as the city's summer demands continue to drain water sources. Lake Meredith, which provides water to Lubbock and 10 other regional cities, dropped to 50 feet as summer demands and heat soaked up the supply. Water levels have fallen low enough that engineers are now looking to tap deeper than was originally intended for the reservoir. Officials say the pipes are part of a larger contingency plan including a pipeline project to pull water from Lake Henry and the expansion of wellwater resources. Mayor Tom Martin says, "it's like investing for your retirement, you can put all your savings in one stock, and that's great if it goes up, but if it goes down then you're wiped out. We can't afford that as a city so that's why we diversify our water supply," The pipeline plans will give the authority a few more feet of lake depth to work with, but officials say there is no cause for concern as the city has diversified their water sources and can pull from wellwater in both Roberts and Bailey counties.