I live on a 22 acre residential lake and am President of the LOA (lake owner association). The lake was built in 1966 as part of a residential development. Over the years a lot of silt has come into the lake via storm water drains and built up several small "islands" that have required dredging over the decades. The silt traps that were originally put in are outdated. Does anyone know anything about silt trap construction? Also can anything be put in in front of where the storm water drains into the lake to slow the pressure down (big rocks or boulders possibly)? During a big rain the outflow may be 30-40 psi.

I build roads on the upland side of my ponds and make forage ponds that double as silt ponds. It is simple to do and when they silt in I just dig them out with an excavator and haul it off. Basically I build the road and put down the covert and then dig the hole on the upland side of the covert. Flood events take the forage down to the ponds from time to time.
Here is a pick from the little make shift road of one I built earlier this year.