Hello all,
I have been tasked with providing options for an expanding a small campus's water system. My previous experience with potable systems is for much larger operations, with 100k gal elevated reservoirs serving a population on the order of 6,000 people. This project is related to a...
I have an older hydrocad model that was built in v10, build 1. Recently I updated to the latest build, and when I ran the model, received this error on a pond with an exfiltration and culvert outlet. I don't recall getting this error before, when was this error added to the list?
Hello,
I am attempting to re-create a hydrocad model based on output reports. This original model was created in version 8.5, and I am using version 10.00 to build it. I have success in getting similar outputs for the subcatchment and reach nodes, but the pond node is behaving oddly, my...
Hello all,
I have been asked to estimate the extent of groundwater level drawdown for a proposed swale (2' deep) that extends through a wetland (presumed groundwater elevation 6" below grade). The regulator is asking for an area around the swale that will have a lowered water table elevation...
Hello,
I have worked with the simple method model for determining annual pollutant load in the past. Now I'm tasked with doing it again, but I was given this source for the model formula:
http://des.nh.gov/organization/divisions/water/stormwater/documents/wd-08-20a_ch8.pdf
formula is on the...
Hello all,
I am working on a storm facility located in sandy soils, so I plan to use infiltration practices. One of the design criteria is the detention of a 1-year storm event over a 12 hour period.
When modeling my pond without infiltration, I can size a control orifice that provides the 12...
In my state, the regulators typically look at the COM detention time to determine if their criteria are being met. In the model I'm working on now, the plug flow time is nearly double the COM time. Reviewing HydroCAD's website entry on the difference between the two, I believe that using COM...
I am looking at the new feature that provides the pollutant loading for subcatchment areas. IN the reports, it appears that the results give a quantity of pollutant per storm event. Is there a way to get an annual pollutant loading number from this new feature?
Thanks,
- shane
Hello,
I am re-permitting a gravel pit and working on a noise model. Unfortunately, the crusher is inoperative at the moment and I cannot directly measure noise levels. Does anyone have information on 'typical' crusher noise levels that I could use to plug into a noise attenuation model...
Our firm is looking into offering vibration testing for the commissioning of buildings. We have reviewed the materials at the NEBB website and have a decent handle on what goes into the testing procedure. Now we are looking to rent a meter to do some dry runs.
Does anyone here have...
Hello,
I am starting the environmental/permitting work for a sand & gravel operation. I'm looking for safety regulations for pits (e.g. max cut slopes, design of benching, min tree clearing width at top of slope, etc.) on the MSHA website, but quickly got lost. Anyone have a link to this type...
Hello,
I am working on the design of a culvert that serves as the primary outlet of a stream-fed pond. I have sized the structure as an 83" x 57" pipe arch. 100-yr storm flow is 163 cfs, and the pond rises 3.25' during the storm. The embankment of the pond is about 10' tall at its highest...
I am working on a model of some underground storage chambers with a catch basin upstream acting as a diversion structure. The catch basin has two outlets, one 2' higher than the other to bypass larger storm events.
The chamber system is designed to infiltrate/detain the 1-year storm. This...
(cross-posted to earthwork and storm forums)
I have two ponds in the center of a residential neighborhood that have slumping banks. The soil has eroded in 12" x 12" chunks in the steeper sections, and a more uniform erosion in the shallower sections. The side slopes of the pond range from 3:1...
I have been tasked with creating a model of a 1700 acre watershed of a brook. This model will be used to find at what rain event a diversion structure (basically a long weir along a portion of the streambank) will start to come online.
A previous consultant performed a model, but did not use...
This question is kind of a mash-up of a this forum and the hydrocad/storm modeling forum. I have been asked to model storm flow down a swale that has check dams installed. I am planning to use hydrocad's pond node and use the exfiltration device for an outlet. I need to spec the hydraulic...
I have been working on a retrofit to an existing stormwater pond (increasing its detention time for a 1-year storm event). In the state review process, the project has been referred to the Dam Safety section, which is concerned with the pond's performance during the Probable Maximum...
I am evaluating the velocity of flow through a rip rap channel with stone check dams. Modeling just the reach with the rip rap (n=0.04) gave a velocity of about 3 ft/s. When I used two ponds (modeling the two check dams), the velocity was much higher (6.2 ft/s).
I recognize this as the pond...
In Vermont, we are using the regulations developed with the help of the Center for Watershed Protection. One of the criteria, the channel protection volume (CPv), requires "12 or 24 hours of extended detention storage for the 1-year, 24-hour storm event." Most of the time I have used...
first: sorry if this comes up twice, I think the post was eaten the first time around.
I have been tasked with estimating the amount of yearly soil loss in a roadside swale. The swale is approximately 1,100 feet long, and drains about 12.5 acres in a low-density residential area. The...
