I am using a local rainfall distribution and estimating the peak inflow from the maximum depth of rainfall for any given interval. Rainfall is given in 15 minute increments. Since I am looking at the worse case scenario I am estimating that none of the rainfall is abstracted. I am not really...
I am doing a small drainage study for an area less than an acre.
The purpose of the study is to recommend solutions to correct basement flooding for a series of homes. Homeowners being as they are, really can't give me alot of information on the flow rate entering their basements or the depth of...
If your outlet ditch is greater than 1% and you have significant flows into the pond, I would consider several ways to dissipate the energy. A simple one may be to extend the pipe add a manhole and have a significant step up from the manhole invert to the inflow pipe. Lay the pipe leaving the...
This is a state submission for Maryland and they require a TR-20 Model. I was able to model the hydrology in Hec HMS with similar results so I am going to request permission for using HEC HMS.
Al Budinsky
Skelly and Loy
Harrisburg, Pa
I am trying to model some hydrology which includes a seep at a fixed base flow (50 GPM) and a diversion of flow from a channel to a small pipe (appox. 1000 gpm or 2.2 cfs)
What is the best way to model this in Win TR-20?
I don't have any cross sectional information for a reach.
Is there way to...
I noticed at least a 20% difference in flows computed using HEC HMS to TR 55 and TR 20 using the SCS method.
Has anyone else had this problem and if so were you able to get the models calibrated more closely?
Thanks
Al
I have been recently told that the height of stairs should be 7" and the tread 11" Traditonally, I have always used an 8" riser and 12" tread. Is it still valid to use an 8" riser?
I have over ten years experience using Survcadd for various civil applications. While I believe you still need other packages there are features of the Hyrdology modules worth noting. The pond capacity and design are pretty decent. I was able to balance the earthwork for my pond construction...
The use of TR55 for peak storm sewer design is sort of cumbersome. TR 55 and TR 20 are more tools to check the response of a watershed to changes in the watershed. There is a chart which relates CN's to C-Factors. I usually compute the peaks using Win TR 55 and then place them into a storm sewer...
I noticed at least a 20% difference in flows computed using HEC HMS to TR 55 and TR 20 using the SCS method.
Has anyone else had this problem and if so were you able to get the models calibrated more closely?
Thanks
Al
I would develop a stage discharge relationship for the bridge.Depending on the size, this can be modeled as some sort of culvert or obtained from Hec-Ras. I am assuming you can calculate the storage behind the structure. I am not sure how you are modeling the flows(ie, scs, rational, etc.) You...
I am trying to model a user generated hydrograph in hec hms with out much luck. I get these errors:
ERROR: Hyetograph gage not specified for Subbasin-1
ERROR: Precipitation data not defined for subbasin Subbasin-1
I simply want to route some hydrograph values through the model. I don't have...
Not sure why you would be compacting topsoil as this wouldnot be very beneficial for turf establishment. Usually a respread of 4 to 6 inches is sufficient. I have had problems with topsoil respreads of 12" especially on steep slopes.
