Engineered Bioswale & Stormwater Treatment Media
Washed Sand, Screened Soil, Organic Compost
 
StormFlow Bioretention Soil Mix is a professionally engineered stormwater soil blend designed for bioswales, rain gardens, and low-impact development (LID) systems. Formulated for controlled infiltration, pollutant filtration, and long-term structural stability, this mix supports both hydraulic performance and healthy plant establishment in municipal, commercial, and residential stormwater projects.
 
Tested for hydraulic conductivity and built with carefully balanced sand, organic matter, and mineral components, StormFlow™ delivers dependable performance in engineered drainage and bioretention applications across Marin, Sonoma, Alameda, Contra Costa, San Francisco, and San Mateo counties.
 
- Engineered for stormwater compliance
- Designed for bioswales & bioretention planters
- Balanced infiltration & nutrient support
- Bulk delivery available
 
Engineered Blend Composition
Blend Composition
StormFlow Bioretention Soil Mix is precision-formulated to achieve consistent hydraulic performance, structural stability, and long-term filtration capacity. Each batch is blended using a ratio of mineral and organic components:
65% Concrete Sand – Provides structural stability and controlled permeability
20% Screened Topsoil – Supplies mineral balance and plant-supporting structure
15% Organic Compost – Enhances pollutant filtration, nutrient retention, and biological activity
This engineered ratio supports optimal infiltration performance while maintaining sufficient organic content for vegetation establishment in bioswales, rain gardens, and stormwater treatment systems.
 
  Download StormFlow Soil Mix Data Sheet  
 
Common Applications
StormFlow Bioretention Soil Mix is engineered for stormwater management systems where controlled infiltration, pollutant removal, and vegetative support are required.
 
Primary Applications
• Bioswales – Linear drainage channels designed to filter and infiltrate stormwater runoff
• Bioretention Planters – Urban curbside and parking lot stormwater capture systems
• Rain Gardens – Residential and commercial infiltration landscapes
• Low Impact Development (LID) Projects – Green infrastructure installations
• Stormwater Treatment Basins – Engineered filtration zones
• Parking Lot Runoff Management – Commercial drainage systems
• Municipal Compliance Projects – Projects requiring engineered soil media
 
Bioretention Soil Mix Delivery – Bay Area
StormFlow Bioretention Soil Mix is available for bulk delivery throughout Marin, Sonoma, Alameda, Contra Costa, San Francisco, and San Mateo counties. We specialize in professional-grade stormwater soil delivery for contractors, municipalities, civil engineers, and commercial landscape projects.
 
Minimum Order: 10 Cubic Yards
This product is engineered for larger stormwater and LID installations and is not sold in small retail quantities. Lead time of ~ 2 to 4 business days required.
 
Available Delivery Options
1. Bulk Dump Truck Loads Delivered loose and dumped directly at your job site. Ideal for: Bioswale trench installations Rain garden excavation backfill Commercial bioretention planters Municipal stormwater systems. Our residential-friendly dump trucks can access most urban job sites while still handling contractor-sized volumes.
 
2. Two Cubic Yard Super-Sack Tote Bags
Available in heavy-duty white bulk bags (totes).
- Each tote contains approximately 2 cubic yards
- Forklift or equipment required for placement
- Ideal for urban sites, tight access areas, and phased installation projects
- Tote packaging & handling cost applies
Super-sacks provide controlled placement and reduce material waste on engineered projects.
 
Frequently Asked Questions - StormFlow Bioretention Soil Mix
Q. What is StormFlow Bioretention Soil Mix used for?
A. StormFlow Bioretention Soil Mix is engineered for stormwater management systems including bioswales, rain gardens, curbside bioretention planters, and low impact development (LID) projects. It is designed to provide controlled infiltration, pollutant filtration, and healthy plant establishment in municipal and commercial drainage systems.
 
Q. What is the infiltration rate of StormFlow Bioretention Soil Mix?
A. The surface infiltration rate at 0% slope is approximately 0.54 inches per hour, with saturated hydraulic conductivity tested at 11.38 inches per hour (ASTM F1815). Actual field performance may vary depending on compaction, slope, and installation practices.
 
Q. What is the composition of StormFlow Bioretention Soil Mix?
A. The engineered blend consists of:
• 65% Concrete Sand
• 20% Screened Topsoil
• 15% Organic Compost
This ratio is designed to balance permeability, nutrient support, and structural stability for stormwater systems.
 
Q. Is StormFlow Bioretention Soil Mix available in super sacks?
Yes. StormFlow Bioretention Soil Mix is available in 2 cubic yard white super-sack tote bags. Tote packaging & handling costs apply. Equipment such as a forklift or loader is required for placement.
 
Q. Does this mix meet municipal bioretention requirements?
StormFlow is laboratory tested for hydraulic conductivity and produced using a controlled slab-mixing process to ensure consistency. However, project specifications vary. Contractors and engineers should verify that the mix meets specific city, county, or project requirements prior to installation.
 
Q. What plants work best with this bioretention soil?
A. StormFlow bioswale mix supports most stormwater-tolerant plant species. However, boron-sensitive plants may not perform optimally. Always consult project plant specifications for municipal or engineered installations.