Sacramento–San Joaquin Delta, CA · $265B (proposal)
SAC-23 · Sacramento-San Joaquin Delta Aqueduct Super-Siphon
Twelve tunnel-boring machines carve a 150-mile subterranean aqueduct network beneath the Delta, capturing catastrophic winter snowmelt and routing it to underground storage — flood control and water banking in a single invisible system.
Pros
- Solves California's two-headed water monster — too much in winter, too little in summer — with one system.
- Underground storage loses almost nothing to evaporation, unlike surface reservoirs in a warming climate.
- The farmland above stays farmland; zero surface footprint.
Cons
- 150 miles of tunneling in California's seismic zones is a genuine earthquake-collapse risk.
- $265B for water infrastructure dwarfs every water project in American history combined.
- Twelve simultaneous TBM operations would strain the global supply of machines and crews.
Feasibility: California's actual Delta tunnel project — a single 45-mile conveyance — has been debated for decades at ~$20B. This proposal is roughly 3x the length at 13x the cost, in the same seismic geology. The concept (capture winter surplus underground) is exactly right for California's future. The scale needs to be cut by 80% to be real.
Aerial mock-up: Invisible from the sky — the 150-mile aqueduct buried deep underground while the valley floor above remains dedicated entirely to agriculture.
