Hello,
I am designing a sediment basin in NJ. The basin design includes a riser pipe (currently shown as 24" diameter, and the discharge coefficient selected is 0.60. We need to get the maximum water surface elevation to come down and i was considering designing an anti-vortext device on top...
I have a situation where the peak flow OUT is calculated to be slightly larger than the flow IN.
Logically, i'm not sure i can think of a scenario where this makes sense... I've tried finer routing, and several different types of minor adjustments but cannot change the situation.
The township...
Hello All,
Hoping you might be of assistance. I have designed an infiltration basin in HydroCAD.
For the "Exfiltration" Outlet, i have selected the "Conductivity" type as we have a known conductivity of 17.25 inches per hour. Previously, the basin bottom was 2.5 feet above the groundwater...
Hello,
We usually do not get involved with mounding analysis for our infiltration basin designs - unless required by the reviewing engineer.
Our NJ state requirement for infiltration basins is to have a 2 foot separation to groundwater, and to "halve" the percolation rates of the soil for the...
Hi all,
Got into a debate with a municipal review engineer about roughness coefficients for Lawn area.
I do most of my stormwater calculations using the HYDROCAD program. The typical list of values for grass manning's coefficients is:
Short grass prairie - 0.15
Dense grasses...
For years, i have used Hec-Ras to produce flood elevations for streams including those that have culverts. I simply model the culvert in Hec-Ras.
I have just recently come across a project where a very renowned civil engineer received an approval from our state's DEP (NJ) by treating the stream...
Good morning all!
I have a situation where a drainage area flows towards and existing inlet with a 10" pipe discharge.
I setup hydrocad to show that the 10" pipe is the primary discharge, the parking around around the inlet is a small "pond" with a weir created which represents the low point...
Using HydroCAD to prepare calculations to meet NJ state groundwater recharge requirements (infiltration of the increase in 2 year storm runoff volumes).
After applying the design infiltration/conductivity rates, where can i view how much total water has been infiltrated? The summaries indicate...
Hello All:
My company has to review a site plan for a small 10 unit towhhome development. So I’m reviewing the plan and almost everything on the job is tight, but meets the ordinance requirements. The only real concern I have is with respect to stormwater.
The site is about an acre. The...
can someone please explain where the term "Thrie" comes from?
for years I thought this was a spelling mistake of the word "three" but my state's approved guiderail is called "Thrie". A local reviewer commented on my latest plan set saying that I needed to correct this spelling mistake. I'd...
Hello All,
I seem to be having trouble performing the encroachment calculation for my model.
I created a second profile (PF2) with the same flows and cross sections as the original (PF1) and ran the encroachment option using method 4 (with all cross-sections designed to have a 0.2' rise), which...
Does anyone else have a problem with importing the DXF cross sections from Hec Ras into Autocad? I exported the sections to DXF all at once (using the multiple option), but when they're all at bizarre scales... lFor example, on one section stations 0+00 to 1+60 instead of scaling 160 feet...
Hello,
I am currently using hec ras 4.1.0 and have a situation where i have the stormwater from a 300 acre drainage area traveling down a stream and the stream becomes a 30" pipe that is 200 feet long, and then the stream picks up again on the other side. The pipe is way under capacity...
Hello,
I have been modeling with hydrocad, hydraflow, and pond pack for years. I have occasionally encountered situations where the incoming flow is less that what is leaving the pond. This may occur during a large storm event when the water is flowing out of a low flow orifice and building up...
Hello,
I am currently using hec ras 4.1.0 and am having a difficult time determining the best way to model my situation.
I have a Reach (call it Swale 1) which ends at a HW where water can either enter a 36" pipe or fill up and over into an overflow swale.
Currently i have setup 3 reaches with...
