jobarr-
I've been in similar situations with respect to estimating design flows, so I appreciate the thread. Here's an example of a peak to design flow relationship, for well-based small community water systems in New Hampshire - see table 405-5 on pdf page 13 in...
Low flows can be tough to measure on a continuous basis, but what about a batch basis? For a short term flow study, could you temporarily block the discharge pipe, divert the water immediately upstream to a sump, place a pump in the sump equipped with some sort of totalizing flow meter on the...
What is the volume of hot oil drips vs volume of (I assume) cooler temperature water? If there is enough cool water volume, perhaps a sump with a baffle or similar to cool the hot oil in before it flows to the pipe(s)?
I have heard of issues with water coming out of the pavement, with flatter grades that the 10-20% you suggest (albeit it was at the entrance to a parking lot and I'm not sure that they did much in the way of subgrade check dams). I don't know about the soils where you are, but inducing...
Neenah Foundry is a longstanding name. R-6665? May need to check with mfg. for loading data. Does it need to be opened much? How about a hatch overlaid by a heavy steel plate. I would stay away from a grate.
beej, are the lines on the FIS depicting HGL or water surface elevation? I see the 10% annual chance profile appears to go through the culvert while the 0.2% and 1% are above, then drop sharply beyond the culvert. Without any more embankment info, I would see the profiles as (highest*) water...
I agree with psmart, the level of detail of analysis depends on what you are designing or checking. In northern new Hampshire, my firm's typical practice is also to design stormwater facilities for typical rainfall events, i.e. 24 hour 10-, 25-, 50-, or 100-year rainfall, with typical...
Likely stormwater regs will dictate much of the site design. A few things to consider for site design would be: cover for utilities (get local frost depth as mentioned), provision for snow plowing and storage areas, think through what is likely to happen with stormwater devices relative to...