How much Delta outflow could California capture?

Of the water that flows out of the Sacramento-San Joaquin Delta, only the outflow above the D-1641 environmental and water quality requirement is available to capture. This dashboard runs that surplus day by day from 2015 through 2025 against the pumping and conveyance rates that exist today, because a flood pulse lasting a few days cannot be captured at a fixed pumping rate even when the monthly total looks small. Move the levers to see how added pumping, recharge conveyance, or forecast-informed reservoir operations change the share captured.

Share of surplus outflow current infrastructure can capture

Surplus is outflow above the D-1641 environmental requirement, limited by daily pumping and conveyance rates and the lever settings below.

Where the outflow goes, by water year (million acre-feet)

Environmental and water quality requirement (D-1641) Surplus current infrastructure can capture Surplus beyond daily capacity, passes to the ocean

Each bar is one water year of total Delta outflow. Teal is the protected environmental requirement. Green is surplus that current daily pumping and conveyance could capture. Red is surplus that passes to the ocean because on those days it exceeds infrastructure capacity. Water years 2015 and 2025 are partial.

The environmental requirement shown is the D-1641 minimum monthly Net Delta Outflow by Sacramento Valley water year type: numeric standards from July through January, and the salinity-governed February through June period shown at the 7,100 cubic feet per second Chipps Island level. It is the quantified regulatory minimum, one layer of the species, Old and Middle River, and water quality rules that govern Delta operations.

Levers

Environmental requirement (multiple of D-1641): 1.0

South Delta pumping capacity, Banks plus Jones (cfs): 14900

North Delta recharge conveyance (cfs): 1000

Forecast-informed upstream capture rate (cfs): 0

Every capture path is limited by a daily rate in cubic feet per second, which is the binding constraint; groundwater basins and reservoirs have room for the volume. Raising pumping, conveyance, and forecast-informed capture shows the captured share climb and the volume passing to the ocean fall. That gap is the infrastructure and operations opportunity.

Month by month (animated)

2015-01

Explore the live data

Current conditions, updated daily, for briefings, board updates, and explaining the year to reporters and the public.

The Sacramento-San Joaquin Delta explained. The rules behind the requirement line: export to inflow ratio, outflow, X2, and Old and Middle River flows.
How much water can California store?. Reservoir storage statewide, for placing the captured volumes in context.
Recharge toolkit. Where and when captured water could be recharged, for briefing a district or a GSA.

Sources: California Department of Water Resources, Dayflow daily Delta outflow, inflow and exports, water years 2015 to 2025; State Water Resources Control Board, Water Right Decision 1641 Net Delta Outflow objectives; California Data Exchange Center, San Luis Reservoir and upstream reservoir storage; DWR Sacramento Valley water year classifications. Cite as: "How much Delta outflow could California capture?" conciseVerbosity, 2026-09-11, https://api.conciseverbosity.com/delta-dashboard.