Hi, I'm trying to model a water quality / detention pond in HEC-HMS that has two outflow structures draining in different directions. One outlet (riser) drains to a second pond, the other (concrete spillway) discharges to a channel. I was hoping for some advice on how to split the flow in the...
Hi, I was just wondering if anyone is using FHWA HY-8 7.2 on a Windows 7 (32 bit) computer. I recently installed Windows 7 and I'm trying to finish a project that I started using HY-8. It seems to work fine until I try to define an irregular roadway section. It gives an error that says "MFC...
I am modeling a detention pond. The detention is provided by building a dam on a stream. A large diameter culvert is proposed in the stream bed.
This was permitted by the USACE. Two of the conditions of the permit were:
1. The detention time must be less than 2 hours
2. The pipe must be...
Hi,
I am working on a residential subdivision where we are tying into an existing waterline that looks something like this-
exhyd1 exhyd2 exhyd3
0----------------0---------------0
Our site is adjacent to existing hydrant 2. In order to perform our fire flow calculations...
Hi,
I am modeling a proposed residential subdivision for adequate fire flow. I have done this several times before, but the available flow and pressures at the connection to the existing system were based on hydrant flow tests. I then used that data to model the connection as a reservoir and...
Hi,
We are designing a storm drain system for a subdivision which ties directly into a system downstream that is currently under construction. The downstream system was designed by others and was supposed to be designed to carry our flow. The engineer of the development downstream was kind...
Hi,
We are designing a distribution system for a subdivision. We have had two hydrant flow tests done at this point and can't provide calculations that show that there is sufficient pressure for fire flow. There are 3 pump stations that pressurize the system we are tying in to. There was only 1...
Hi,
We recently recieved a review comment requesting that we install watertight joints on a RCP storm drain line due to the fact that the HGL showed that the pipe was surcharged.
This particular line is the most upstream segment in the system and the surcharge is due to inlet control.
My...
Hi,
Is there a command that will automatically assign vertex elevations to a 3d polyline by reading them from a surface? I am thinking I either read about a way to do this or ran across the command at some point in the past; or is this just wishful thinking?
Thanks in advance
Hi,
I was hoping for some advice concerning a project that I am working on that is currently under construction. I realize that earthwork calculations are somewhat of a best guess, and that strippings depths vary greatly from site to site / region to region.
The problem that I am having on...
I was looking for some opinions on the sheet set tool. Does anyone use this? If so what in you opinions are the pros / cons. I have read a little about it, however I never seem to get the time to read and experiment with it enough to understand it fully. Is it worth taking the time to do this...
Hi, We have inherited a project on which a wetlands delineation was performed by a certified wetlands scientist. As far as we know the delineation was never verified by the USACE. Is this a requirement if we are not disturbing wetlands and disturbing less than 150' of stream?
Also could...
Hi,
I was hoping someone could recommend a good economical way to pipe runoff from roof drain downspouts and tie to a storm drain system. Our particular project is a daycare with parking in front and a playground on the other 3 sides.
There are roughly 3 to 4 downspouts per side. How is this...
I am working on a residential subdivision in which the municipality requires 100% compaction of the aggregate base course under the curb and gutter. The contractor on this project constructed the curb and gutter about 8 months ago prior to having any compaction tests done. The municipality...
I'm confused, please help. Why is it that as time of concentration for a watershed goes up, peak flow goes down?
And does it make sense to split a relatively small watershed(<100ac)into subwatersheds with different time of concentrations and combine hydrographs? Does this assume that a storm...
