How much are homes on top of Cambria Cavern worth? A year later, county doesn’t know

The property tax protest season is wrapping up this week in Williamson County, but homeowners in a Brushy Creek neighborhood don't know how much their homes are really worth because the county's chief appraiser has never seen houses built on top of a known cave before.

WILLIAMSON COUNTY, Texas (KXAN) — The property tax protest season is wrapping up this week in Williamson County, but homeowners in a Brushy Creek neighborhood don’t know how much their homes are really worth because the county’s chief appraiser has never seen houses built on top of a known cave before.

It’s been nearly a year and a half since Cambria Cavern opened up at the corner of Cambria Drive and Ephraim Road; workers filled in the portion of the cave under county property and sealed off the entrance, but the underground void is still having an effect on homeowners.

In particular, two homes sit on top of portions of the cave that the county did not fill in. “So it’s hard to say what it’s worth at this point in time,” said Robbin Gersch, who lives in one of the two houses the county says is directly impacted.

He’s looking to sell in the near future so he and his wife can downsize, but he doesn’t know what he can expect a buyer to pay for the home, despite the fact that there have been no structural issues in the 30 years since the house was built.

“If you had 10 houses for sale, all very similar, one has a cave, and the other ones don’t,” he said, “would that be at the top of your list?”

The county’s chief appraiser, Alvin Lankford, said it’s hard to estimate the value because he’s never seen this before. There are 32 known caves around Williamson County, but this is the only one with homes built on top.

The appraisal district dropped the value of both homes by 30%, but Lankford told KXAN he simply doesn’t know if that’s an accurate reflection of the homes’ worth.

“What we did is we assumed that they have a slab problem,” he said. “They do not, but what we had to do was come up with a way of addressing the value issue that the cave may cause.”

Appraisals rely on sale prices of similar homes in the same neighborhood that sellers voluntarily disclose. Since there are no homes like this in the entire county, no one will know what they’re really worth until they sell.

“That’s something the market needs to determine,” he said.

Home prices are still rising outside of the two directly affected properties. Eight homes sold in the neighborhood last year, Lankford said, for about 2% more than their pre-cave values.

That’s a trend the appraisal district has seen elsewhere in the county. The county compared homes within 500 feet of the 32 known caves to those outside 500 feet, and there was no difference in prices. “In fact,” Lankford said, “the homes that were closer to the caves sold slightly more than the homes that were outside.”

Overall, home values within Round Rock ISD’s boundaries rose by 4.95% this year, lower than the 6-7% the area has seen in previous years.

One other home near Cambria Cavern saw a drop in value after the owner, Tim Kelley, protested his valuation last year.

His driveway was blocked off for months as crews worked on the cave, and since appraisals are a measure of the market value in a theoretical sale, the county agreed his house was worth less without a usable driveway. The 25% cut he received means his tax burden is still lower this year, even though his home value is increasing again.

One homeowner near the cave is protesting her valuation this year.

Now that the cave has been discovered, Gersch will have to disclose it to potential buyers. He hopes it doesn’t lower the sale price too much, or even drive away interest altogether.

“There’s a lot of companies moving to Austin and this is a good area,” he said. “Maybe in anywhere from one to five years, [the attention will] die down, the market will be hot and people will want to get into them.”