Looking for advice. We have had water gathering in the back yard from the sump pump run off. I discovered a clogged "french drain?" I ran a hose into the opening of the pvc and found the it had a SOLID clog. I have dug out and cut away slowly and I am finding the pipe to be clogged with clay and gravel. I had cut away 5 ft. and found an elbow. I am now about 8 ft. and still finding the pipe clogged solid. I tried flushing with the garden hose but because of our clay soil and all the gravel the clog is solid. I am having dig and to cut bit by bit. Not sure were all the gravel came from. Am I doing the right thing? Any advise would be appreciate!