📐 Multi-Stage Riser Control (V-Notch Weir, Broad-Crested Weir & Low-Flow Orifice)

Stormwater Riser Orifice & Weir Calculator

Model stage-storage-discharge rating curves for multi-stage precast concrete stormwater outlet control structures: calculate circular low-flow orifice discharge (Q = C_d x A x Sqrt(2gh)), V-notch weir flow, and top broad-crested emergency overflow weir discharge (Q = C_w x L x H^1.5), verifying zero downstream flooding, and drainage margins.

1. Project & Operating Inputs

Outlet Control Structures Installed (Structure Count e.g. 4 Vaults)

Peak 100-Year Head Over Weir (Feet e.g. 3.5 ft Hydraulic Head)

Customer Bid Price for Supplied & Cast Concrete Outlet Vault ($ / Unit)

Precast Riser Box, SS Orifice Plate, Trash Rack, Outfall Pipe & Labor ($)

2. Financial Breakdown & Yield

OUTLET STRUCTURE STAGE-DISCHARGE

Turnkey Control Structure Profit

Civil Stormwater Engineering Margin

0.0%

Gross Revenue / Bill

Total Project CapEx

Operating / Material Cost