🚰 LID Underdrains (Perforated HDPE 6"-12" Pipe, Orifice Control Choke Plate Diameter)

Bioretention Perforated Underdrain Calculator

Size perforated smooth interior corrugated HDPE collection underdrains (AASHTO M252) and restrictor orifice choke plates installed inside outlet catch basins: control hydraulic release rate, ensure bioretention filter bed saturates uniformly for nutrient uptake, and drainage piping margins.

1. Project & Operating Inputs

Filter Bed Underdrain Length (Linear Feet e.g. 450 Linear Feet Pipe)

Peak Filtered Infiltration Flow (GPM e.g. 350 GPM Peak Drainage)

Customer Bid Price for Supplied & Laid Underdrain System ($)

6" Perforated HDPE Pipe, Geotextile Sock, Washed Stone Bedding & Tech ($)

2. Financial Breakdown & Yield

AASHTO M252 UNDERDRAINS

Turnkey Underdrain Drainage Assembly Profit

Civil Utility Drainage Margin

0.0%

Gross Revenue / Bill

Total Project CapEx

Operating / Direct Cost