The current city requirements are to store the 50 year storm while releasing at the pre-developed 5 year rate which creates a significant amount of storage. I see in the outflow table that the pre-developed peak flow is not achieved until much later in the storm event, requiring the need for a...
I have been using HydroCAD to compare hand calculations of TR-55 and have an issue with storage requirements. When using TR-55 a simple process for determining storage volume from runoff is by computing the ratio of peak pre-developed flow over peak post-developed flow and using an equation to...
I have a free version of HydroCAD and am unable to figure out which information I need to size a pond correctly. I used TR-55 to size the volume of storage needed for certain storms by hand, but am unable to use the software to then design a pond, which clearly this is able to do. What...
I have seen the requirements for "Pond Routing" and have found nothing on what pong routing even is. By using various methods you are performing Hydrologic Analysis of an area, but not routing through ponds but rather to possibly a pond or basin. So is there a difference in methods, or does pond...
Yes, I did some calculations for this for proposed areas of design, and the storage volume required by the rational method is significantly less. As area increases so does the difference. In the case of a 10 acre development my calculations between TR-55 and the rational method had a difference...
I see what you did for the IDF curve and finding the 24 hour depth using the 24 hour Tc, but does the IDF necessarily produce the proper rainfall distribution for the region or is it just a rainfall depth divided evenly throughout a 24 hour period?
And the D in Q=CIAD is the duration of the...
I guess the question is then, are IDF suitable for volume calculations or are they only suitable peak flow? The city I am doing this study for uses IDF curves to find the volume of storage required to pass the 50 year storm while releasing at the 5 year pre-developed rate. To do this, the peak...
I am performing a hydrologic study between the Rational Method (current method being used), NRCS TR-55 and SBUH (both proposed) and am wondering if IDF curves are based on Regional Storm types. I know that both are used for historical rainfalls, Storm types being rainfall pattern while IDF...
I am currently investigating possible repairs that can be made to a "failing" dike embankment and have been unable to find good references of practices. There is a creek that tends to flash in storm events that is separated from a reservior/old quarry by a dike. Seepage is evident between the...
