Which Waterproof Trousers?

even proofed jeans will never be more than water resistant.

Cotton is a hydrophillic material, the only way to make it waterproof is via the waxed jacket / duck cotton which methods which rely on a lot of wax and the fact that the cotton absorbs the water, fibers expand and together with the wax water runs off. Jeans this waxy would be very stiff and uncombable (think of trousers made out of barbour jacket.)

http://nextecfabric.com/epic_cotton.html had a jacket made of this stuff once, was great dont know why i sold it.