Is it time to divert the Blanco?

The stinky, slimy mud wasn’t even dry yet when, following the devastating flood of May 24, 2015, talk began of doing “something” about the Blanco River.

As it had in the past — and did again six months later — the normally placid stream-fed stream raged with rainfall. Upwards of 10 inches fell near the headwaters in Blanco in a month that had already been plagued with heavy rain.

A home in Blanco with three vacationing families inside was knocked off its foundation and pitched into the violent stream. Of the eight people in the vacation rental — it was Memorial Day Weekend — only one, plus a family dog, survived. One body was found some 30 miles downstream in Caldwell County and two others — those of a four-year-old girl and a six-year-old boy — were never found.

Reaching San Marcos, the stream flattened out and filled San Marcos’ new Fire Station 5 with a few feet of water and cut off Interstate 35.

And, like it always had, the waters of the Blanco sought those of the San Marcos River, inundating the Blanco Gardens neighborhood on the way and continuing its rage downstream to the communities of Martindale, Staples, Fentress and beyond. 

Not one of Texas’ major rivers, the Blanco is only 87 miles long. But it has the distinction of having no major dams along its course. In contrast, the San Marcos River, at just over 75 miles long, has a number of them — some still standing, some removed due to damage or other factors.

Moreover, the city of San Marcos, and areas in the San Marcos River’s basin, are protected by a series of watershed dams on Sink, Willow and Purgatory creeks. Those dams, built in the 1980s, spared the city the tragedy of three children who drowned near Purgatory Creek in a 1970 flood.

But those who live along the Blanco, and the areas like Blanco Gardens that it perennially floods. And now, the wheels set in motion after the two floods of three years ago are beginning to hit pavement.

On Wednesday, a community meeting will beheld at 6 p.m. at the San Marcos Activity Center “to update residents on proposed infrastructure projects under consideration for flood mitigation on the Blanco River,” according to a city press release.

The meeting is a follow-up to one held April 18 in which city engineers answered questions from the public concerning how the millions of dollars in disaster recovery funds the city received from the federal department of Housing and Urban Development would be spent.

Though short on specifics, engineers attending that meeting mentioned possible channels to divert Blanco floodwaters including adding a great capacity to “Bypass Creek,” which would channel the torrent to a channel running from upstream of Blanco Gardens to outside the city limits, roughly parallel to Hwy. 80.

Eric Ratzman, project manager with Halff Associates, notably issued a caveat during the April meeting. “There’s not just one silver bullet to solve this,” he said.

That meeting, and the one on Tuesday, is open to anyone who wants to attend and in April, residents of Martindale showed up hoping for reassurances the diversion channel wouldn’t increase their risk of flooding.

Assistant City Manager Laurie Moyer provided it. “If those solutions show that they impact you, we can’t do harm,” she said back then in explaining that projects to help San Marcos residents are forbidden if they harm others. “You can’t, for the protection of San Marcos citizens, flood Martindale,” she said.

“Since the first meeting … city engineers and consultants have studied the various projects under consideration for feasibility and flood mitigation,” the city press release said.

Presentations Wednesday will include one by city engineers on the Blanco Riverine Flood Mitigation Project. Questions will be taken, and maps of the Blanco will be available to address concerns about specific locations.

No one died in the floods of three years ago but in all, some 1,558 San Marcos homes were destroyed or damaged in May and October.