I purchased a new home and the irrigation control valve box is constantly flooded. Often not to the top and it is often flooded even when the irrigation hasn't been run in weeks. Therefore I am thinking it is more of a design reason it is flooding, as it is downgrade from much of the system rather than a leak. The builder and landscaper both are claiming that is normal and the control valves are designed to be submerged. That is not my general understanding. Is that correct? What is the best way to fix this, assuming it is not a leak?