PROJECT OVERVIEW

The Woodson’s Reserve Diversion Channel was designed and constructed to divert overflow from Woodson’s Gully, directing it through the Woodson’s Reserve residential development and the active sand mining operation before ultimately discharging into the West Fork San Jacinto. This diversion channel mitigates impacts from the residential development without causing adverse effects upstream or downstream.

Phase II of the project focused on the sand pit operation crossing. Per an easement agreement with the sand mine property owner and operator, two channel crossings, each rated for 100-ton loadings, were required to allow access across the channel. To reduce overall construction costs, the upstream crossing (108 LF of 9’-6” × 4’ RCBs) was designed as a low-water crossing, allowing flow to overtop the road during a 100-year storm event. This approach enabled the use of smaller reinforced concrete boxes within the channel.

SERVICE DETAILS

Spanning a low-water crossing with a high-water surface elevation introduced risks associated with buoyancy and rapid drawdown that could compromise the stability of the structure. To address these challenges, the design incorporated nine 6’ × 4’ reinforced concrete box (RCB) culverts, carefully sized and extended to provide an adequate factor of safety under rapid drawdown conditions. To further resist buoyancy, the gravity weight of the structure was increased, and a foundation-level ledge was introduced to enhance sliding resistance and improve overall stability.

In addition, the culverts were required to support a specialized 100-ton vehicle—loading that significantly exceeded standard design requirements. To ensure safety and structural integrity under this extreme loading condition, a detailed finite element model was developed to perform a moving load analysis. This approach enabled precise evaluation of stress distribution and structural response, ensured compliance with all applicable AASHTO requirements, and resulted in a safe, efficient, and durable design.