Stormwater BMP Calculators
Design green infrastructure, detention facilities, and low impact development practices for sustainable stormwater management.
Green Infrastructure
Design sustainable stormwater practices that mimic natural hydrology
Rain Garden Design
Size rain gardens for stormwater capture, infiltration, and water quality treatment
Bioretention with Underdrain
Design bioretention cells with underdrains for low-permeability soils
Permeable Paver Design
Design permeable pavement systems including base storage and infiltration
Green Roof Retention
Calculate green roof retention performance and runoff reduction
Conveyance BMPs
Design vegetated swales and channels for stormwater conveyance and treatment
Infiltration Practices
Design systems that return stormwater to groundwater
Detention & Storage
Design systems that temporarily store and slowly release stormwater
Detention Pond Sizing
Size detention ponds using Modified Rational and storage-indication methods
Storage Volume Calculation
Calculate required detention storage volume for peak flow reduction
Underground Detention
Design underground storage systems using pipes, chambers, or vaults
Cistern Sizing
Size cisterns for rainwater harvesting and stormwater reuse
Learning Resources
Understand the theory behind the calculations
Rain Garden Design for Beginners
Principles of sustainable stormwater management
Learn more: Rain Garden Design for BeginnersStormwater Compliance Checklist
Permit requirements and regulatory guidelines
Learn more: Stormwater Compliance ChecklistStorm Drainage Design Fundamentals
Peak flow control and outlet design
Learn more: Storm Drainage Design FundamentalsLooking for a different type of calculator?
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