# US strategic oil reserve nears critical level raising cavern damage concerns Structural integrity of salt caverns at risk due to rapid drawdowns - **Source:** [US Top News and Analysis](https://brifing.si/source/635540e9-943e-450d-ae52-ae0bfe3b67eb) - **Published:** 2026-08-15 - **Topic:** [Business](https://brifing.si/c/business) - **Original article:** - **On Brifing:** https://brifing.si/s/9abf84c9-98d7-4184-94d7-5942de501e36 ## Reserve at lowest level in four decades The US Strategic Petroleum Reserve (SPR) has dropped below 300 million barrels, hitting its lowest level since the 1980s. A 172-million-barrel emergency sale was conducted due to the Iran war. Current levels are far below when the reserve was initially filled. Experts warn that levels below 300 million barrels pose risks to the salt cavern infrastructure. ## Structural risks to salt caverns The SPR stores oil in 60 salt caverns located in Louisiana and Texas. Rapid drawdowns could compromise the structural integrity of these caverns. Professor Misra from Texas A&M University explained that below 300 million barrels, pumping rates decrease and salt pillars supporting the cavern ceilings weaken. This significantly increases collapse risks in the underground storage facilities. ## Controversy over 70M barrel threshold The Energy Department maintains that at least 70 million barrels must remain for safe operations. However, President Biden's energy advisor Hochstein called this figure 'nonsense.' Rapidan Energy analysts estimate the practical operational floor is between 170-250 million barrels. Current levels are approaching 243 million barrels after recent drawdowns. ## Water injection dissolves salt walls The extraction process involves injecting fresh water into caverns, which dissolves salt walls and compromises structural integrity. Professor Misra explained this flattens cavern ceilings and thins critical salt pillars separating adjacent caverns. A GAO report confirmed that each drawdown-refill cycle expands cavern volume and reduces long-term viability of the storage system. ## Pumping systems at risk When inventory falls below 300 million barrels, the SPR loses its rapid response capability for emergencies. Thinning oil layers can cause pumps to intake sludge instead of oil, damaging equipment. Energy Department officials admitted they're maintaining aging infrastructure with 'Band-Aid' solutions. As of December 2025, a quarter of SPR inventory was unavailable due to outages. ## Growing political debate Both parties have expressed concerns about cavern integrity. Republicans criticized the Biden administration's record 180-million-barrel release during the Russia-Ukraine war. The Trump administration claims responsible management of this national security asset. The GAO confirmed repeated drawdowns alter cavern shapes, with most caverns rated in 'very good condition' after 2022 inspections despite long-term concerns. ## Historical use exceeded design The SPR was originally designed for only five full drawdowns but has executed dozens of releases over 40 years. Professor Misra stated this intensive use has caused severe cavern deformation. Falling salt chunks from ceilings weaken the aging reserve's structural integrity. While GAO's 2022 review found most caverns in 'very good' condition, experts emphasize accumulating long-term risks. ## Critical national security asset The SPR serves as America's primary insurance against energy crises. Current inventory levels risk inadequacy during hurricanes or other emergencies. Hochstein warned 'below 300 million slows flow rates and puts us in danger.' Experts stress the urgency of refilling reserves and infrastructure investments. This vulnerability could potentially impact global energy markets given the SPR's strategic importance. ## Sources covering this story - https://www.cnbc.com/2026/08/15/strategic-petroleum-reserve-spr-oil-iran-war-caverns.html — --- _Summary written by Brifing from the original reporting. Copyright in the original article belongs to its publisher; read the full piece at the link above._