Low Impact Development (LID) Stormwater Solutions
Advanced sustainable civil engineering mimicking natural site hydrology to capture, treat, and infiltrate urban stormwater runoff.
What is Low Impact Development (LID)?
Low Impact Development (LID) is a highly regulated structural stormwater management strategy designed to protect local watersheds from urban pollution. When land is developed, natural soil permeability is replaced by impervious concrete and roofs. An engineered LID plan introduces specialized structural Best Management Practices (BMPs)—such as infiltration basins, biofiltration planters, and permeable pavements to capture, filter, and infiltrate the first flush of a rain event directly on-site, drastically reducing the volume of toxic pollutants entering public waterways.
Comprehensive Stormwater Design Capabilities
Grading & Public Works Clearances
Expediting approvals for mass tract grading, hillside slope stabilization, B-Permits, and ADA right-of-way improvements.
Multi-Agency Coordination
Concurrent management of approvals across overlapping jurisdictions, including local Public Works, Caltrans, Fire Authority, and local Water Quality Boards.
Environmental & Hydrology Approvals
Navigating strict SWPPP (Stormwater Pollution Prevention Plan) and WQMP (Water Quality Management Plan) submissions through local and state environmental agencies.
Biofiltration Planter Design
Engineering custom, structurally lined bioretention cells utilizing specific engineered soil matrices and vegetation to naturally scrub pollutants from water.
Subsurface Infiltration Systems
Designing subterranean rock-beds or perforated chamber systems (such as StormPrism or CULTEC) to store and infiltrate water beneath parking lots.
Site Permeability Mapping
Conducting hydraulic calculations to optimize the ratio of pervious vs. impervious surfaces, minimizing the overall physical footprint of required BMPs.
Other Civil Engineering Services
Permit Processing Rough Grading Drainage Design Erosion Control Hydrology SWPPP Water Quality Management Plans (WQMP) Precise Grading Water Distribution Systems Street Improvement Plans Sewer Design Utility Plans Utility Extensions Sewer Area Studies Drainage Improvements Fire Access Upgrades Dry Utilities Water System Plans Change of Use Zone Changes Conditional Use PermitsEngineered for Strict Urban Realities
Dense Flatland Urban Infill: Implementing modular, vertical biofiltration planters adjacent to zero-lot-line structural walls where surface area is non-existent.
Commercial Parking Lot Retrofits: Integrating porous concrete, interlocking permeable pavers, and localized bioswales within high-traffic parking stalls.
Industrial Logistics Parks: Sizing and balancing massive, open-air detention basins designed to process millions of gallons of runoff from industrial tilt-up roofs.
How We Develop a Compliant LID Plan
- Geotechnical Infiltration Analysis: We review localized percolation tests to determine if the site’s soil can physically handle direct water infiltration.
- 85th Percentile Volume Calculation: Utilizing specialized county hydrology software to calculate the exact volume of water the site must capture and treat during a benchmark storm event.
- BMP Selection & Feasibility: Selecting the optimal system (Infiltration vs. Biofiltration vs. Harvest/Use) based on spatial constraints and soil conditions.
- Plan-Check Clearance: Submitting the comprehensive LID or Water Quality Management Plan (WQMP) report to municipal sanitation and engineering departments for rapid approval.
Navigating Compliance & Regulatory Codes
In Southern California, an approved LID or WQMP plan is a strict legal requirement to clear your grading permit. Our civil engineers navigate the rigorous MS4 permit regulations enforced by the Los Angeles (LARWQCB) and Santa Ana (SARWQCB) Regional Water Quality Control Boards. We specialize in engineering solutions for regions with high clay content or high water tables, utilizing lined biofiltration systems when direct soil infiltration is geotechnically unfeasible or unsafe.
Low Impact Development FAQ
What is the difference between LID and a standard drainage plan?
A drainage plan focuses on the quantity and speed of water routing to prevent immediate site flooding. An LID plan focuses on the quality and treatment of that water, ensuring it is clean and managed sustainably before leaving the lot.
What happens if my site has clay soil that won’t absorb water?
If a geotechnical report proves infiltration is impossible due to poor percolation rates, we pivot to an engineered Biofiltration or Biotreatment system. These systems filter the water through specialized soil layers on-site before slowly discharging the clean water into the city storm drain.
Will LID structures reduce my buildable property space?
They can if designed poorly. However, our civil team specializes in space-saving mechanics, utilizing subterranean storage vaults beneath parking stalls or slim perimeter planters to preserve your buildable real estate.
Integrated Engineering Solutions
Out-of-context stormwater plans can compromise structural assets. If an infiltration basin is placed too close to a building foundation, it can super-saturate the soil and trigger foundation settlement. The Eden Group coordinates our civil stormwater routing directly with our structural engineers, ensuring that all infiltration zones maintain critical safety setbacks and structural liners to keep your foundations completely dry and structurally sound.
Clear Your Stormwater Plan-Check Without Delay
Secure an optimized, fully code-compliant LID or WQMP design. Contact The Eden Group today to speak with a senior civil stormwater engineer.