We have a Richmond 40 gal water heater. The sewage pipe in our basement recently overflowed, leaving about 2 inches of water in the basement. Once we got the mess cleaned up, we noticed we have no hot water. We checked the pilot on the hot water heater and found it was out. Tried re-lighting it and it would stay on until we tried to adjust the temperature. Once we got it to the temperature setting we wanted, it looked like it was going to kick the burner on, but then the pilot would go out. The water heater was working fine before we found the water. Can anyone help please?

It is quite likely that you have moisture, if not actual water, in the burner it self. The gas is under a very low pressure and any moisture in the burner will prevent the gas from coming out the holes of the burner element. Most likely the burner will have to be removed so you can dry it. You could try drying with a hair dryer without removing but that would take quite some time.