Embankment level

[Sportway]

I m desingning a roadway that goes through a flat and inundation susceptible (in both sides of the road) so drainage will only be used to keep the same water level in both sides.
How or what is the method to obtain the level that is required for my embankment. (hydric balance or something like that?

 

[BigH]

First you will need to establish the high flood level - or that level that you will use to establish the height of your embankment. If your embankment is too low, you may get overtopping from time to time. Secondly, you will need to establish "normal" flood levels. Once these are established, set your pipe invert to be below these - since your culverts are only equilization culverts for floodings. Others may have more technical comments, but this is the gist of it in my opinion.

 

[Sportway]

Thanks BigH, but my question goest to "how do i establish the high flood level?" since i dont have observed data of height in those sectors.

 

[BigH]

That difficult. Many times I see designers talking with the local folks as to "how high has the flooding ever got?". In the States, I would imagine that the US Conservation Authority should have good records on most streams and flood plains. Try contacting them; they also might be able to put you onto someone else. Oh, yeah, many times engineers, too, look at the rocks or old buildings to see if there are tell-tales as to high water marks.
Best of luck.

 

[gbam]

Definately talk with the locals, they are a good source for information. If this is a floodplain to a river or creek you can check wqith FEMA to see if they have some information. There is always methods for determining flood levels, but I think you need to continue your research of the area first.

 

[pablo02]

As gbam mentioned, try visiting with FEMA (in the States) -- almost all areas will have established flood zones (10 year, 20 year, 50 year, 100 year, etc.) for establishing flood insurance requirements, etc. In many cases, FEMA does not have this information but should be able to provide the local jourisdictional group responsible for that information. Caution, though, in areas of rapid urban growth, these zones may be recent but already outdated... also be carefull with Area Planning and/or Zoning Commissions -- they sometimes forget to review the flood control documents unless you request specific flood related data from them... [I once installed an industrial well near a creek with the casing 6" above the highest ever recorded flood stage at that location -- my co-workers joked about this well sticking so high above the ground -- and 10 years later, a flood came within ½" of topping the casing -- although we elected to resterilize the well, I felt vindicated for my original installation]