Can a Texas Waterway, such as a creek, legally be dammed without a permit?

My new neighbor has bought the property next to us to improve and sell. The "improvements" include, digging out the creek damming the creek and clearing a great deal of under brush. During these improvements he set fire to a brush pile while our county was under a burn ban and left it unattended (he left the property) as an end result the fire burned 6 acres of our land and the forestry service had to come in and dig trenches so the fire wouldn't jump around. Now our county has had some flash flooding over the last few days and his dammed up creek has caused a great deal of errosion, it even eroaded his own new asphalted roadway to the back of his property. We are planning to sue for property damages for the fire because he hasn't offered an apology or attempted to pay for any damages and tried to blame our daughter for the fire. What I am wondering is can we also sue him for the proerty damages that was caused by his creek being dammed and suddenly overflowing.