Grid · Analysis

Aliso Canyon is a gas field. It is also a grid backstop.

Angelenos know Aliso Canyon for the 2015 methane blowout. California's grid regulators know it as a reliability asset, and that is why it is still open.

BY THE RENEWABLE ENERGY LA EDITORS · FILED OCTOBER 22, 2026 · 6 MIN READ ·

How a gas field became a grid backstop

Aliso Canyon stores gas underground in a depleted oil reservoir, operated by the Southern California Gas Company. On an ordinary day, the LA basin draws gas straight from interstate pipelines. On a hot afternoon, when air conditioners push electricity demand up and gas plants ramp to meet it, the pipelines can run short, and the field can inject stored gas into the system within hours. At last public report the field was allowed to hold on the order of 68 billion cubic feet, far below its physical maximum but well above the tight limits imposed right after the blowout.

That electricity link is indirect but real. LADWP runs coastal gas plants such as Scattergood and Harbor, and CAISO (the California Independent System Operator, which runs the grid for most of the state outside LADWP's territory) leans on other gas units across the region. None of them burn anything unless the gas is there. The CPUC's own reliability studies have repeatedly found that, without Aliso Canyon, Southern California faces a higher risk of gas shortfalls on extreme days, and that finding is what keeps the field open.

Raising the cap while studying the exit

Late in 2023 the CPUC voted to raise the field's allowed inventory, a decision it framed as protecting gas and electric reliability and holding down winter price spikes. Critics, including many Porter Ranch residents, argued the vote rewarded the operator and pushed closure further away. Both readings point at the same tension: the thing that makes Aliso Canyon dangerous, a very large volume of pressurized gas near homes, is also what makes it useful as a buffer.

Closure itself lives in a separate CPUC proceeding that has run for years without a firm end date. It asks whether the basin can be kept reliable without the field, and if so, by when. The honest answer at this desk is that it depends on two other things: building enough electric capacity and battery storage to replace gas peaker plants, and cutting gas demand enough that the buffer is no longer needed. Neither is on a fixed schedule.

What it means on your block

For a ratepayer, the field shows up in two places you can almost see. One is reliability: if you have sat through a Flex Alert on a triple-digit September day, when the state asks you to hold off on the dishwasher until evening, the gas buffer is part of what keeps those alerts from turning into outages. The other is cost, because gas bought cheaply in spring and held for winter is meant to soften the price spikes that hit your gas bill and, indirectly, the gas-fired share of your electric bill.

In Porter Ranch and the nearby communities of Granada Hills and Chatsworth, the calculus is more personal. Those residents live with the field as a daily presence, not an abstraction, and the health monitoring and well-by-well inspection overseen by the California Geologic Energy Management Division (CalGEM, the agency that regulates oil and gas wells) is the part of this story that matters most to them. Reliability for the basin and safety for the neighborhood are not the same question, and the state has to answer both.

Worth watching this month

1. Watch the CPUC's Aliso Canyon docket for new filings in the closure study, a schedule that has slipped before and could slip again.

2. Watch for the CPUC's seasonal gas reliability assessments heading into winter, which spell out how much stored gas the state expects to lean on.

3. Watch CAISO and LADWP readiness reports for whether planned battery storage is coming online fast enough to ease the basin's reliance on gas peaker plants.

4. Watch CalGEM's well-inspection updates for the field, the routine safety checks that rarely make news but matter most to nearby residents.

5. Watch the California Energy Commission's Southern California load forecasts, since faster electrification could change how much gas backstop the basin actually needs.

Where this dispatch reads

California Public Utilities Commission: Aliso Canyon, www.cpuc.ca.gov/aliso, The regulator's hub for the capacity decisions and the separate closure proceeding (government source).
California Energy Commission, www.energy.ca.gov, State load forecasts and energy demand data for Southern California (government source).
California Geologic Energy Management Division (CalGEM), www.conservation.ca.gov/calgem, The state agency that regulates and inspects the wells at the field (government source).
California Independent System Operator (CAISO), www.caiso.com, Grid-operator reports on seasonal reliability for most of California.
Southern California Gas Company: Aliso Canyon, www.socalgas.com/aliso-canyon, The operator's page on the field's status and operations.
Los Angeles Department of Water and Power, www.ladwp.com, The city utility that runs several coastal gas plants and reports on power supply.

Questions readers have asked

Did Aliso Canyon reopen after the 2015 leak?

It never fully closed. Injections were halted and inventory capped for a time, but the field stayed in service as a withdrawal source, and the state later allowed it to store more gas again.

Does Aliso Canyon make electricity?

No. It stores natural gas, which separate power plants burn to make electricity. The field matters to the grid because those plants need a reliable gas supply on peak days.

Is the field going to close?

Maybe, but there is no firm date. A CPUC proceeding is studying whether the basin can stay reliable without it, and the answer depends on how fast gas demand falls and electric replacements get built.

Who regulates it?

Several agencies share the job. The CPUC oversees gas reliability and utility costs, CalGEM regulates the wells themselves for safety, and the California Energy Commission tracks the broader energy demand picture.