By Jon Herskovitz
AUSTIN, Texas, June 17 (Reuters) - Tropical Storm Bill wasdowngraded to a tropical depression on Wednesday as it movedacross Texas, bringing heavy rains that flooded streets andsnarled transportation in the state where severe weather killedabout 30 people last month.
There were no reports of major damage or deaths from Bill,the second named tropical storm of the 2015 Atlantic hurricaneseason, which came ashore near the sportfishing town ofMatagorda on Tuesday and then took a path into central Texas.
The storm is expected to bring sustained winds of near 35mph (56 kph). Rainfall is expected to be 4 to 8 inches (10 to 20cms) over eastern Texas and eastern Oklahoma and 3 to 6 inchesover western Arkansas and southern Missouri. Some areas couldsee as much as 12 inches (30 cms), the National Hurricane Centersaid.
The heavy rains could cause rivers already swollen fromtorrential rains in late May to spill over their banks again.
"These rains may produce life-threatening flash floods," theweather service said.
About 120 flights were canceled at airports in Dallas andHouston, some of the nation's busiest, as of 7:45 a.m. CDT,tracking service FlightAware.com said. Houston had nearly adozen road closures caused by high water.
The storm has prompted the National Weather Service to issuea flash flood watch for an area stretching from the Texas coastinto Oklahoma, Arkansas, Missouri and Illinois, affecting morethan 20 million people.
In Austin, Dallas and Houston, which were hit by floods inMay, the owners of stores in low-lying areas deployed sandbags.
In Sealy, about 50 miles (80 kms) west of Houston, policehad to rescue people caught in rising water as the floods cutpower to numerous homes overnight.
"Please remain indoors and do not leave unless it isabsolutely necessary," the Sealy Police Department said on itsFacebook page.
Voluntary evacuations were called for some flood-prone areassouth of Houston.
Oilfields in the Gulf of Mexico and near the coast were notimpacted by the storm. Refineries and a nuclear power plant, theSouth Texas Nuclear Generating Station in Bay City, alsooperated normally.
Flooding could snarl work in onshore oilfields, butproducers including EOG Resources and ConocoPhillips said they were unaffected.
More than 45 percent of U.S. refining capacity and half ofnatural gas processing capacity sits along the U.S. Gulf Coast. (Additional reporting by Terry Wade, Kristen Hays, Erwin Sebaand Anna Driver in Houston; Editing by Bill Trott)