Project Overview
JLC Engineering conducted a comprehensive hydrology and hydraulic analysis for Canterwood, a proposed 120-acre residential development in Menifee, California. The study aimed to evaluate stormwater management solutions, ensure flood protection, and comply with regulatory requirements. The project will include 446 residential lots, along with supporting infrastructure, and is designed to effectively manage stormwater runoff while maintaining environmental sustainability.
Study Area & Drainage Conditions
The Canterwood project is located in Riverside County, bounded by Holland Avenue to the north, Eucalyptus Road to the east, Craig Avenue to the south, and Leon Road to the west. The site naturally drains westward into the Menifee Lakes system, making it a suitable outlet for stormwater discharge.
Existing conditions included natural and agricultural land cover, with a mix of permeable and impervious surfaces affecting runoff characteristics. The study considered three conditions:
- Existing Condition – The pre-development land cover and drainage characteristics.
- Interim Condition – The developed Canterwood site while surrounding areas remain unchanged.
- Ultimate Condition – Full buildout of both the Canterwood project and surrounding developments.
Analysis & Methodology
JLC Engineering utilized industry-standard methodologies and software tools to assess stormwater behavior and infrastructure design:
- Hydrology Analysis:
- The Rational Method was used for smaller drainage areas (<300 acres).
- The Unit Hydrograph Method was used for larger areas (>300 acres) following Riverside County Flood Control & Water Conservation District (RCFC&WCD) guidelines.
- Hydraulic Analysis:
- The WSPG hydraulic modeling program was used to analyze storm drain capacities.
- Street drainage and storm drain systems were designed to meet 10-year and 100-year storm event criteria.
- Seven bioretention basins were integrated to capture and treat runoff before release.
Key Findings & Results
The hydrology and hydraulic study confirmed that the proposed storm drain infrastructure and flood management measures are sufficient to protect the development and surrounding areas. Key results include:
- Effective Drainage Infrastructure: Stormwater is managed through a network of unlined channels, box culverts, and storm drain laterals directing runoff into the Menifee Lakes system.
- Flood Protection Measures: The proposed system meets Riverside County’s street design capacity standards, ensuring streets remain functional during major storm events.
- Water Quality Management: Seven bioretention basins treat stormwater before discharge, reducing sediment and pollutants to meet water quality standards.
- No Additional Mitigation Required: Due to the project’s natural drainage into Menifee Lakes, additional mitigation for increased runoff was deemed unnecessary.
Conclusion
JLC Engineering’s hydrology and hydraulic analysis provided a robust framework for stormwater management at Canterwood. The project successfully integrates flood protection, regulatory compliance, and environmental sustainability. By incorporating bioretention basins, storm drain networks, and efficient drainage pathways, the development is well-equipped to handle storm events while ensuring long-term water quality and infrastructure resilience.