Another idea would be to scale up the classic boy scout plastic sheet still and place it over a big pan of water. Instead of digging a pit, use a framework to hold up the plastic. The top surface of the plastic could be formed into allot of ridges and troths using rods. From the side it would look like a whole bunch of Vs strung together. Under the bottoms of the Vs troths can be placed to collect the drips. Those troths can then direct the water to the catch jug.
Couragated fiberglass panels?