The last thing the West Coast needs is more people moving into the area with water already at a premium.

But that's exactly what's happening in areas where exceptional drought has a firm grip , according to new data from the U.S. Census. Of the top 50 fastest growing counties, 10 are in California. Only Texas, with 11, has more.

For the most part, people are migrating to metro areas, but they're also moving west and south, the data found. But when the population growth is combined with recent U.S. Drought Monitor surveys, it becomes more evident that a lot of people are moving into areas where the water supply is already stressed.

(MORE: Ugly Battle For Precious Resource Underway )

The Brookings Institution recently analyzed the data from the Census findings , as well as the county-level Drought Monitor results, to create two maps that make it easier to see where the biggest problems lie.

<img class="styles__noscript__2rw2y" src="https://dsx.weather.com//util/image/w/County-Pop-Increase-2000-to-2014.jpg?v=at&w=485&h=273&api=7db9fe61-7414-47b5-9871-e17d87b8b6a0" srcset="https://dsx.weather.com//util/image/w/County-Pop-Increase-2000-to-2014.jpg?v=at&w=485&h=273&api=7db9fe61-7414-47b5-9871-e17d87b8b6a0 400w, https://dsx.weather.com//util/image/w/County-Pop-Increase-2000-to-2014.jpg?v=ap&w=980&h=551&api=7db9fe61-7414-47b5-9871-e17d87b8b6a0 800w" > This image shows the changes in population of each U.S. county from 2000 to July 2014. (Brookings Metropolitan Policy Program) (Brookings Metropolitan Policy Program)

<img class="styles__noscript__2rw2y" src="https://dsx.weather.com//util/image/w/County-Drought-Map-2015.jpg?v=at&w=485&h=273&api=7db9fe61-7414-47b5-9871-e17d87b8b6a0" srcset="https://dsx.weather.com//util/image/w/County-Drought-Map-2015.jpg?v=at&w=485&h=273&api=7db9fe61-7414-47b5-9871-e17d87b8b6a0 400w, https://dsx.weather.com//util/image/w/County-Drought-Map-2015.jpg?v=ap&w=980&h=551&api=7db9fe61-7414-47b5-9871-e17d87b8b6a0 800w" > The U.S. Drought Monitor's county-by-county totals, updated May 26. (Brookings Metropolitan Policy Program) (Brookings Metropolitan Policy Program)

"In total, the country’s population grew by about 45.2 million from 2000 through July 2014, most of which (25.8 million, or 57 percent) occurred in counties experiencing some level of drought," Brookings said. "In addition, nearly 9.5 million more residents are living in counties that are currently dealing with a severe drought or worse, where crop losses are likely to occur, water shortages are common, and water restrictions may be imposed."

And as bad as the droughts have been in recent years, they pale in comparison to the decades-long "megadroughts" that scientists say are becoming increasingly more likely in the West and Desert Southwest before the end of the century, according to a study released earlier this year.

"The future of drought in western North America is likely to be worse than anybody has experienced in the history of the United States," said Benjamin Cook, lead author of the megadrought study and a climate scientist at NASA's Goddard Institute for Space Studies.

MORE ON WEATHER.COM: California's Long-Term Drought