Expert Hydrology Engineering
Advanced mathematical modeling of stormwater runoff to design resilient, code-compliant flood mitigation infrastructure.
What is a Hydrology Study?
Hydrology engineering is the complex science of understanding how water behaves on a specific piece of land during extreme storm events. Before a single pipe or basin can be designed, a Hydrology Study mathematically models the volume, velocity, and peak flow rates of stormwater runoff generated by the new development. This study acts as the undeniable mathematical proof submitted to municipal Public Works departments to verify that the proposed drainage infrastructure will not fail or cause downstream flooding.
Comprehensive Hydrology 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.
Peak Flow Calculation
Utilizing the Rational Method and local county hydrographs to calculate the exact cubic feet per second (CFS) of runoff during 50-year and 100-year storm events.
Watershed Analysis
Mapping off-site tributary areas to determine how much external water naturally flows onto your property from higher elevations.
Mitigation Sizing
Providing the exact mathematical sizing requirements for detention basins, underground retention tanks, and high-capacity storm drains.
Other Civil Engineering Services
Permit Processing Rough Grading Drainage Design Erosion Control Precise Grading SWPPP Water Quality Management Plans (WQMP) Low Impact Development (LID) 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 PermitsHydrology for Complex Environments
Floodplain Developments: Engineering heavy mitigation for properties located near the Santa Ana River or within FEMA-designated Special Flood Hazard Areas.
Massive Impervious Sites: Modeling the severe spike in runoff caused by paving hundreds of acres for logistics centers and retail parks.
Canyon & Hillside Tracts: Calculating the intense velocity of water rushing down steep grades to prevent devastating mudflows in foothill communities.
How We Conduct a Hydrology Study
- Data Acquisition: We aggregate localized soil types, historical rainfall intensity data (isohyetal maps), and topographic surveys.
- Pre-Development Modeling: Calculating how the raw, undeveloped land currently handles water absorption and runoff.
- Post-Development Modeling: Calculating the dramatic increase in runoff caused by adding roofs, driveways, and parking lots.
- Delta Mitigation Design: Engineering the specific infrastructure required to capture and hold that “extra” water so it discharges at a safe, pre-development rate.
Navigating Compliance & Regulatory Codes
Every county in Southern California (Los Angeles, Orange, Riverside, San Bernardino) has completely different hydrology manuals, software requirements, and mathematical standards. Our civil engineers are deeply fluent in these localized county mandates. We ensure that our hydrology reports pass meticulous peer reviews by municipal Public Works departments, satisfying all CEQA and local flood control district requirements.
Hydrology Engineering FAQ
Is a Hydrology Study different from a WQMP/LID plan?
Yes. Hydrology focuses on the quantity and velocity of water to prevent flooding. WQMP and LID plans focus on the quality of the water to prevent pollution.
Why is the county asking for a 100-year storm analysis?
Municipalities require engineers to prove that your site’s drainage systems will survive a catastrophic storm event (a storm that has a 1% chance of happening in any given year) without flooding public streets or adjacent properties.
What is a detention basin?
It is an engineered pit or underground tank that temporarily holds a massive volume of stormwater, slowly releasing it into the municipal system to prevent overwhelming the city’s pipes.
Integrated Engineering Solutions
Hydrology is the math; civil drainage is the execution. The Eden Group houses both the hydrologists who run the complex flow models and the civil engineers who design the physical pipes and grading plans. This seamless integration ensures that the mathematical requirements of the Hydrology Study perfectly match the physical realities of the site plan, preventing costly municipal redesigns.
Require a Municipal Hydrology Report?
Ensure your project meets strict county flood control standards. Contact The Eden Group today for expert hydrology modeling and engineering.