I've seen them building farm dams by professionals where they have to be sealed with a CLAY layer or they leak I'd raise that runway and put a slight crown on it and mix something special in the top surface. . Fortunately it will never grow grass on it, but will be dusty and geta few prop, nosewheel strut. and Paint nicks. Forget a run up Bay. . Work on it after the right amount of rain has fallen on it . nev