riser installed on downstream end of pipe 2

[jcirish]

What are effects of installing a flashboard riser on the DOWNSTREAM end of culvert by mistake? Smaller Flows, erosion,whatever?

 

[LincolnPE]

Extreme embarrassment, being made fun of, object of never ending ridicule.

 

[jcirish]

Very funny, but I am victim of this bungle. I own 19 acres N of mitigation bank that has poor design n construct. No anti seepage collars, pipes too small, half round risers with inlets Only one third size of barrel oufall when they should be 1.5 times that.
NEED TECH ANSWER TO EMBarass Fdot designer and sjwmd acceptor of this lousy system. Thanx

 

[cvg]

anti-seepage collars are generally not used anymore. you shouldn't have any
riser on the downstream end of the culvert will cause numerous problems and should be removed
- silting up the pipe
- pressurized culvert pipe
- reduced capacity
- erosion
- plugging with trash and debris

 

[LincolnPE]

Sedimentation occurring in the pipe due to inhibited velocity and backwater. Sediment will drop out of the low velocity flow instead of being transported and passed through the culvert. If what you are saying is true, you should insist the riser obviously be removed and a proper flared end section be installed, with subsequent energy dissipation structure installed downstream of the flared end section to prevent erosion (i.e. riprap runout).

 

[jcirish]

Thanx Lincoln, CVG. your replies were very helpful and much appreciated. God bless. john