The Texas flooding has claimed the lives of 30 people and President Barack Obama has declared it a major disaster. The rain has caused flash flooding in many parts of the state, washing away homes and flooding roads, making evacuations more difficult.

Torrential rains have already given Texas the wettest month on record, according to Texas A&M climatologists. And extreme river and creek flooding has broken many records and swept away hundreds of homes. Rivers and lakes around cities such as Houston, San Antonio and Dallas have all swelled.

The flooding wiped out many homes in San Marcos, which lies between Austin and San Antonio. In Houston, many had to take boats into the streets to evacuate their homes before the water got too high. Hundreds of vehicles were stranded on Highway 45 in Texas as many abandoned them to reach higher ground.

The National Guard has been deployed to search river banks for missing and dead. In a tiny town south of San Antonio, homes were washed away overnight and a thousand volunteers made up more than 70 search teams looking for the missing.

Officials and meteorologists were also keeping a close eye on rising river levels in southern Texas as floodwaters moved downstream from the north. The National Weather Service issued a flood watch for portions of Central and South Texas.

The severe storms have caused at least $27 million in infrastructure damage. Texas transportation officials have said the figure is expected to rise as the state continues to tally damages caused by extreme weather during the past week. According to the Texas Department of Transportation, roadways in 167 of the state’s 254 counties suffered some level of storm damage in the month of May. At least 155 roads in Texas were still underwater or closed due to damages following the series of storms that began Memorial Day weekend.