Does anyone with experience in dam construction have familiarity with sand/gravel filters?
In my research I came across numerous papers including the
FEMA Technical Manual: Conduits Through Embankment Dams and
Filter Diaphragn Design Considerations that indicate anti-seep collars are old technology and continue to be used because “that’s the way it’s always been done”. The current “Best Practice” for controlling seepage is sand/gravel filters. These sound very similar to what Bob Lusk refered to in another thread as a “toe drain”.
P.S. Chapter 6 of the FEMA manual has the info on sand filters if you just want to download that part but the whole manual is interesting reading if you’re the construction type and have time to download 33 megs.
