If the goats were to get out of your property then it would be a pain in the ass to get them out of that drain your talking about, if that's were I think you are,
There used to be deer and wild pigs use the drain as a funnel to move north/south,
I helped a lady get her sheep out of the drain about 5 years ago with Coco, I would never do it again, I don't know how we all got out with out being bitten by Tiger snakes and dugites,
I believe I shore a farriers sheep, that leases a property not far away from you,