Thanks for all the assistance!!!
I found a reference in the appendix of the Corps manual to define the upper nappe which should tell me when the water surface truely impacts the gate.
I'm trying to calulate flow for a tainter gate on an Ogee spillway. To be more specific, for the transition zone from overflow over the ogee to orifice flow. HEC-RAS uses an iterative process for Head/gate opening = 1 to 1.25 to evaluate this transition zone. I found this in the hydraulic...
The NRCS reference Blueoak is talking about about is the National Engineering Handbook part 633 chapter 26. You will need some soil gradations and then you can follow the 12 step process outlined in Chapter 26. There are some very good examples in there and also some basic ASTM gradations in the...
Thanks to everyone! I see everybodys experience, training, and the occasional Google search turned up the same info I had. When Chow released his Book in '59 he had that very nice methodology using n0,n1,n2,...etc. Apparently FHWA and USGS got together and released WSP 2339 (there is another...
While every textbook and reference in the world has extensive descriptions and methods for determining Manning's n in natural floodplains there seems to be nothing out there for urban, suburban, or commercial areas. I've worked through some different methods making guesses at some parameters but...
The pipe is already installed (some time ago?) so no specific info on the pipe other than: 15" dia corrugated plastic pipe.
Doing a hydrology analysis on a watershed with 3 dams and we are rehabin the most downstream dam. The upper 2 dams used cpt for their outlet works (very small dams)...
Anybody got any references on Clarks R for mountainous watersheds? I've got urban, suburban, and rural conditions.
Anybody got a link to Clarks 1945 paper? When I google it I got pages and pages of links were others have referenced the paper but not a direct link to his paper.
Thanks
You may have a problem with your initial conditions assuming your inflow hydrograph always has enough flow. HEC-Ras hates to run "dry". Try adding some initial flow and minimum flow to your hydrograph. I would start small, say 50cfs, and work up. Sounds like your model runs once there is enough...
I would look into NOAA-NWS IFLOWS program. They also give grants to assist local communities purchase and maintain flood warning systems.
http://www.afws.net/
two additional points:
1) FEMA generally uses regional regression equations and I'll bet you put a ittle more effort into your hydrology. Personally I have noticed that regional regression equations don't work for small waterseds like this one!
2)Is your design to pass the 100 yr or to prevent...
thanks for the responses. It is as I feared that no such materials are available like those for other disciplines. I have the ASAE study guide which is less than a 1/4" thick and is mainly a practice exam.
Thanks JF for the reference binder idea. I do that for references at work and tab...
Mick,
you will have to complete a hydraulic flood study of the section of stream and some distance up and downstream. The process you are about to undertake is what FEMA will call a CLOMR (Conditional Letter of Map Revision)or you might get away with a LOMR. I suggest you contact the local...