At the Plum Creek site in Castle Rock, storm flows had caused major washouts and structural damage to both the stormwater pond and the adjacent access road. Cavitation around the existing downspout further compromised the drainage system, creating safety concerns and preventing crews from accessing the pond for maintenance. CDOT brought in Pase Environmental to restore functionality and protect the area from future failures.
Pase rebuilt the access road using high-strength foam injection, restoring the subgrade without extensive excavation. The downspout, which had been severely eroded, was fully redesigned to withstand extreme stormwater flows. To stabilize the bank, crews installed large 24-inch riprap and constructed the downspout in stages due to the steep slope and lack of top access. A new washout-prevention design was also implemented — Pase added a 12-inch curb and soil-filled riprap to reinforce the structure and prevent future erosion.
Crews regraded the stormwater pond to restore hydraulic function and improve long-term performance, completing all work during the hibernation period of the threatened Preble Jumping Mouse. Extreme caution was taken throughout construction to protect the species and its habitat.
The repairs were delivered on schedule and under budget — providing CDOT with a durable, cost-conscious solution that extended the life of the stormwater and roadway systems.
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