Don't know why you require to drill seed if you use the mats too. Unless your dam is dried hard rock clay by now. After my experience, I would like to see 'um muscle that drill seeder on that kind of slope! I bought a cheap shoulder carry seeder and got some good exercise. Only took about two hours to fertilize and seed the whole dam. Then my 15 yr old and I rolled out the mats and staked them down. Not one bit of erosion. Seed took just great.
