The reference to the 24-hour event is in regards to the storm water detention, the NOAA Atlas 14 "I" value is regarding culverts/ditches. If the contributing basin from top to outfall (about 2.5 acres) is all sheet flow with no defined channel, around 550 feet long, is it still applicable to...
The subdivision regulations state calculations should be completed for 25-year 24-hour event, which is like 0.2 in/hr. Is that really my intensity for design?
Yes, I am using the precipitation estimates.
I normally work in really large drainage areas, so I may be overthinking this...
I have a small site, less than 5 acres. I need to calculate pre-post project stormwater calcs.
My plan is to use rational equation and use NOAA Atlas 14 for precipitation intensity (I) in the equation. Looking...
I am modeling a pond, and my outlet structure is an inline weir, but it has a bridge across the top. Should this be done with a custom weir defining the rectangular opening and use the weir coefficient for the broad crested weir? Not sure if there is a more appropriate way to define this in...
I have an existing pond with a riser primary spillway and earthen emergency spillway.
For the current conditions, the primary and emergency spillway were defined using a rating curve. I am working on a redesign of these spillways to pass certain rainfall events, and did not choose to define...
To model a lake in hydrocad with a normal pool elevation set by the primary spillway, is it necessary to define any area under the pool elevation?
Also, should the lake be included in the watershed, noted by defining the lake and watershed separately inside the subcatchment?