Great From 1A feet and approaching record territory. With no outlet, the lake is entirely dependent on evaporation to control its elevation. However, a paradox comes into play when the lake level is very low. That's because an increase in lake salinity also slows its evaporation. About 40 percent of the lake's inflow comes from the Bear River, and 28 percent is from direct precipitation. The Weber River adds 18 percent and the Jordan River another 12 percent. The lake can rise quickly at times. For example, in August 2011, the lake was up 3.3 feet over the previous August, thanks to a snow-packed winter, wet soils and nearly full area reservoirs. What are some of the effects of a low Great Salt Lake? Rupke said because the lake is so shallow, even a modest rise can greatly increase its surface area. It is estimated that for every 1-foot of increase or decrease in lake level, about 44,000 acres of mud flats are inundated or exposed. With decreases, that means a chance of more dust storms are also possible around the lake shore. Rupke also said that a lower lake level concentrates the salt and chemicals in the lake, making mineral extraction more efficient. That is, as long as intake canals or ponds for such industries can still reach or pump in the briny water. Another obvious effect of low Great Salt Lake levels is on boating. Larger boats at the Great Salt Lake Marina on the south end of the lake are now relying on a crane to reach deep enough water. Plus, the average depth of the lake is 14 feet at 4,200 feet in elevation, meaning its average depth now is just under 8 feet. And, the lake's single deepest known "pocket" is now less than 28 feet deep.