Peak discharge problem help

[mjoneswvu]

I'm working on a run-off problem and need some help with the approach. The problem is as follows:

What is the peak discharge for a 500 acre rural property given a storm duration of 4 hours. No other information is provided in the problem. What methodology is the most appropriate to tackle this one?

 

[mjoneswvu]

I'm working on a run-off problem and need some help with the approach. The problem is as follows:
What is the peak discharge for a 500 acre rural property given a storm duration of 4 hours. No other information is provided in the problem. What methodology is the most appropriate to tackle this one?

Sorry, I forgot to mention that the problem also indicates that the discharge requested is for the 10 year storm. The problem is from an old text which is water damaged so it's tough to read (seems like I need to spend the money on a new text). I would imagine that an intensity of 5.2 in./hr., assuming a C=0.2 would get me close if rational is used.

 

[Fluvial]

Look up the constraints for using the Rational Method - if I recall correctly, 500 acres is a bit too large to be using it.

However, without any other data I suppose you'd just about have to use it.

Is the geographic location given in the problem? Rainfall intensities vary across the country.

 

[hicivil]

The rational method should be used for areas of 100 acres or less. But if you find that you need to use the rational method don't forget to use the adjusted C factor which accounts for the time of concentration.

 

[RIP - VTEnviro]

As a first pass, I'd say Rational Method too. Look at what's given.

Q = C*I*A

C = rural land, check the tables

I = 5.2 in/hr

A = 500 Acres

They don't really give you enough to use TR-55.

 

[Polysloman]

Sorry, I forgot to mention that the problem also indicates that the discharge requested is for the 10 year storm. The problem is from an old text which is water damaged so it's tough to read (seems like I need to spend the money on a new text). I would imagine that an intensity of 5.2 in./hr., assuming a C=0.2 would get me close if rational is used.

What method did they request? Give us some choices so we can get most nearly....

Give this a try http://rational.sdsu.edu/onlinetr55.php

It has all the formulas you'll need for WR

Go get 'em...

 

[Florida Tom]

I'm going to throw my lot in with the rational method folks. With no other information, that's about all you have.