A 66-page report from the Los Angeles County Economic Development Corp. detailed the massive impact that could take place if local water supplies are impacted, but local water officials were quick to allay concern.

“Part of the reason (the LAEDC conducted the study) is to keep the populace aware that water is an increasingly valuable and scarce resource,” said Dan Masnada, COO of the Castaic Lake Water Agency. “And it’s easy for people to assume that there’s no issue or no problem because every time they turn on the tap, water comes out.”

Locally, Santa Clarita water officials have worked diligently over the last few decades to secure that supply, Masnada said.

While the threat of a serious disruption at some point in the next two decades is not only real, it’s likely — seismologists prognosticate a 66 percent chance of a 6.5-or-greater earthquake in that same span — the SCV should be OK, Masnada said.

“The way we’ve insulated ourselves is a combination of a diverse water-supply portfolio and water-banking programs that firm up the reliability and availability of our state water supply,” Masnada said.

The worst-case scenario would involve a disruption of what’s known as the West Branch aqueducts connected to the Santa Clarita Valley.

“That’s what flows into Pyramid and Castaic lakes, and that’s where we take our water out of, Masnada said, adding that about 50 percent of the SCV’s water comes from those two lakes and the other 50 percent comes from the local groundwater supply.

Most of that water is from the State Water Project, which passes through the Sacramento-San Joaquin River Delta.

If a significant amount of water-supply disruption were to occur between now and 2035, which is a projected build-out date for the SCV, an underground banked supply would provide for about two years.

Due to such an emergency surplus, a significant disruption of up to six months likely would be handled without too much of a reduction in supply, he added.

Most of our water use is outdoor, he said, and so a disruption like that might prompt and 11 percent cutback in usage, but that’s the equivalent of watering the lawn a little less often, Masnada said.

“Over the last number of years, we’ve taken quite a few actions to effectively drought-proof us, as far as entering into those banking programs and creating importable water supplies,” Masnada said.