Earthen dams at a California golf course had under-seepage draining quickly through pathways beneath the crest instead of overtopping. A prior repair attempt using conventional materials did not stop leakage, necessitating a trenchless cutoff within the dam crest soils.
Initial Assessment
Evidence indicated internal erosion/voiding beneath the dam crest consistent with underflow through permeable zones in embankment and foundation soils. A complete rebuild posed a higher cost, longer duration, and greater disruption compared to targeted injection, which is aligned with best practices.
Proposed Solution
The application of SW-RP1 was proposed for its low-viscosity permeation, rapid water-activated reaction, and closed-cell mass formation, enabling the creation of a continuous cutoff without excavation.
Procedures
- Set two parallel rows along the dam crest at approximately 24-inch spacing to form a continuous cutoff.
- Drill to the seepage zone and foundation contact, then grout upward in stages.
- Inject bottom‑up to fill each bore and connect holes into a watertight curtain.
- Track pressure, resin take, and reaction to confirm permeation.
- Refill the pond and check for renewed seepage to verify performance.
Results
- Under‑seepage stopped and hydraulic control was restored after cure.
- Approximately up to 80% cost savings vs embankment rebuild, based on industry comparisons of polymer injection versus replacement.
- Rapid turnaround with ~24‑hour cure and no excavation.