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Hey all Right now I use HEC to do some very basic modeling and I would like to expand my knowledge of the program. Can anyone recommend a course or an educational path to help me with my task? Thanks in advance Yak

Unfortunately the Township installed the snouts without first performing an as-built and they have no information on the snout manufacturer. Normally, I would go out after a rain and assume the water elevation is the same elevation of the outlet pipe but these inlets are full of water. I...

Hey All, I have a job where utility lines need to cross a storm sewer line. The Township upgraded all the inlets in the area to include Water Quality Snouts and did not get as-built elevations on the pipes prior to placing the snouts. The inlets are now filled with water and the snouts do not...

Hey all. I have 25 Ac. site with a pond at the bottom. The site is located within a rate restriction zone where the post development flow rates have to be 50% or less than the predevelopment rates. The pond is too small to provide any meaningful stormwater management so I need a stormwater...

Thanks Bridgebuster. Thats exactly what I needed. Yakman

Hey all. Just wondering if anyone has a good source of PDH credits? Usually I get a bunch of credits through vendors but due to covid, I don't have any right now. I'm going to try to get them out of the way while its still cold out and we're still on partial lockdown. Anyone have any...

I would contact your Local USDA/NCRS office. They specialize in agricultural waste management. I used to work for them many moons ago. We never used channels for management. We did use waste retention ponds where you stored the waste and used a grinder pump to pump the sludge into a tank on a...

Hey Guys, Hopefully an easy question for someone out there that does work in Pennsylvania. I'm looking for a table of rainfall intensities for use with the Rational Method. I have a copy of Publication 584 which provides the actual IDF curves but not the data used to make the curve. The...

Check the Hydrographs. Some programs use time of concentration multiplayer to change the shape of the hydrograph. You'll find hydrographs generated by Hydraflow has the traditional triangle shape where the bottom of the hydrograph is 2X the Tc. Other programs will use a mutiplier to make the...

TR-55 states that the Graphical Method requires homogeneous watersheds. Unless I've missed something, the Tabular method has no such limitation. I've modeled the site using both the weighted and non-weighted curve numbers and find that it only makes a marginal difference and does not affect...

Just for the record I modeled the watershed as directed using hydraflow. When routed though the basin, the peak flows from the basin were lower than using the non-weighted curve number so it would seem that using the weighted curve number, at least in this situation, is more conservative.

Okay guys.... I just got off the Phone with a guy that is the Township Engineers Stormwater reviewer and all stormwater comments in the Engineers review are generated by this reviewer. He just told me that I'm not allowed to use weighted curve numbers for a Basin Routing using TR-55. I'm told...

I used to to mine reclamation work in Pennsylvania with USDA. The old way of treating acidic mine discharge (AMD) was to use sphagnum moss to treat the acidic water. The moss worked great when it worked. The problem was that you have to keep water in the moss at a very specific level. Too much...

The outlet will be designed in accordance with the States sediment trap standard. Agreed that the stone will need to be removed and replaced but the maintenance will be no more than a standard sediment trap. Since this is an item that the regulator specifically requested, I am reluctant to...

When I use the maximum porosity of the the stone and multiply it by the length and width if a spillway designed according to the manual you find that, your right, the flow rate is negligible compared to the inflow rate. So I'll design the stone outlet for a two year event and design a spillway...

Does anyone have a reliable source on what the permeability of AASHTO #57 stone would be. I have some sources that have it 0.013 ft/s to 0.03 ft/s. I just talked to the regulator on the phone and I have to provide a discharge analysis for the site while under construction. Somebody must have...

I was thinking of modeling the forebay separately. The basin is so big, the forebay sits up high enough that the peak of the storm will occur before the tail water within the outlet becomes a factor. The invert of the forebay is 5 ft above the invert of the basin. Just looking at the stone...

Hey All, I have a project where the State Regulator is requiring a a Forebay for a large basin. The Forebay has to completely dewater in 72 hours (Township Code) and there is Zero Percolation on the site. The Forebay has been designed to accommodate 1" of runoff from the contributing area...

How deep is the water behind the Dam? I had a Dam removal project where the storage area of the dam was all silted in and there actually wasn't that much water behind the dam. Removal of the dam was surprisingly easy from a permitting standpoint. Although, from the picture, it looks like it's...

The problem is that the EET has already started. Wish I knew about it sooner. By the time you posted it, there wasn't enough time to get all the materials before the classes started. That and one of my professional referrals is MIA. I didn't want to sign up for something and not have the...