Buffalo Bayou buried in unprecedented layers of silt

Runners and bikers returning to Buffalo Bayou Park in the wake of Hurricane Harvey are finding a vastly different landscape - more desert than prairie, blanketed with untold tons of sandy sediment.

It's a yin-yang landscape: Along the water's edge, the park looks like an eerie, otherworldly beach, with trees where they aren't supposed to be. Higher up, many plants look lush, even refreshed.

For the third time since it opened in 2015, Houston's 160-acre central park - a $57 million jewel of urban redevelopment - is grappling with the fallout of flooding. The silt, this time, is dramatic.

"We've never seen sediment like this," said Anne Olson, president of the Buffalo Bayou Partnership, which manages and maintains the park.

The flooding deposited deep drifts of sediment throughout the park, settling most heavily in the wide-open, natural areas called "silt benches" that were designed for that purpose, such as the large "beachy" area just east of the Shepherd Street bridge, where the landscape architects kept tree plantings to a minimum. That means the bayou's curvy redesign is working the way it's supposed to.

Such features are increasingly important to the design of parks across the country. Katharine Burgess, senior director of the Urban Resilience Program at the Urban Land Institute, said cities are looking to invest in flood infrastructure that improves quality of life during normal times and increases preparedness for extreme events. Planners in coastal areas like Miami-Dade County and Norfolk, Va., have recently discussed "flood-ready parks," she said.

Buffalo Bayou Park has been a national model for resilience, surviving the Memorial Day Flood of 2015 and the Tax Day Flood of 2016 before Harvey.

Buffalo Bayou crested at nearly 39 feet during Harvey, and on Wednesday the water still flowed swiftly, about 15 feet above its banks. Olson expects the water to remain high for weeks, as releases continue from the Addicks and Barker dams upstream.

While all of the park's infrastructure is designed to withstand flooding, such prolonged submersion puts banks, trees and footpaths to an extreme test.

On Tuesday evening some people walking along the park's paths ignored closure signs for the park's low-lying asphalt trails, entering a treacherous territory of still swiftly-flowing water, eroded banks and deep, slippery silt. At the very least, they emerged with muddy shoes.

Travis Tyrone Tyson of Katy and his friend Keiory Milton Smith of Cypress ventured too far on the Tapley Tributary Trail on their fancy skateboards.

"Oh, my beautiful wheels," Tyson lamented, as they turned around from the compromised paths.

Too early to estimate costs

Touring the park Wednesday with Guy Hagstette, the director of parks and civic projects for the Kinder Foundation, Olson was pleasantly surprised to find that the 4.6 miles of asphalt footpaths appear to have held up well, with a few major problem areas where they've disappeared. She won't know the real extent of the damage until sediment has been removed.

"The partnership has become quite good at removal of silt from trails and landscape areas after typical floods," Hagstette wrote Wednesday in a status report to the Washington, D.C.-based Urban Land Institute.

This summer the Harris County Flood Control District committed to moving massive areas of silt that had accumulated in the benches from earlier floods. Now that job is bigger. And it's too early to estimate the cost of the silt removal and other repairs the partnership will handle, Olson said.

The partnership receives about $2 million annually from the city of Houston for park maintenance and operations, and those funds have been sufficient for previous flood recoveries. The partnership spent about $300,000 on each of its previous flood restorations.

But the damage from Harvey may extend further.

About 400 park lights were affected.

The beleaguered Johnny Steele Dog Park, a $1.6 million facility within one of the park's lowest areas, is still underwater, again, with silt piled about 4 feet up its fences.

A few inches of sediment crept into the historic Cistern, but its lighting and electrical system were unharmed.

The Dunlavy restaurant, Lost Lake, the Water Works building (which holds the visitors center), and the Sunset Coffee Building near Allen's Landing (the partnership's headquarters) emerged unscathed. Those buildings were designed with flow-through ground floors.

The partnership's 22-person maintenance crew and contractors began clearing trails and removing downed limbs and trees on Sept. 6, but that effort has been handicapped by a shortage of rental equipment. The organization lost all of its own golf carts, mowers and tools during the storm, when its maintenance facility on Memorial Drive took on roughly 3 feet of floodwater.

Still, the Dunlavy's windows sparkled in the morning sun Wednesday as if nothing had happened. And water-loving perennials throughout the park are flourishing after the flood.

Further downstream, where Buffalo Bayou flows through the city's East End to the Turning Basin, the partnership owns about 40 acres - the starting point for a second phase of park development. Their property has bulkheads and held up well, Olson said, but banks in that segment without heavy vegetation have eroded badly and are a mess of fallen trees and debris.

The partnership has put its East End sector meetings on hold until it can assess what's happened. Olson sees even more opportunity there now for the partnership to contribute to "resilient development" that would encompass flood detention, wetlands and appropriate housing.

Heed closure signs

Closer to downtown, Olson and park director Gregg Burks urged visitors to obey trail closure signs and use sound judgement in their choice of paths.

"We just had an event of historical proportions," Burks said. "Park patrons need to understand that running trails stand a very good chance of being slick and covered in heavy sediment."

Montrose residents Dr. Francisco Diaz and his husband, John Dietrich, didn't have to be told. They usually bike the park's complete loop three or four times week. Tuesday was the first day they'd returned since the storm, and they walked, pausing to watch the water rushing under the Sabine Street Bridge.

The damage looked as bad as they expected, and they worried about all the old, beautiful - and still submerged - trees. They figure they'll be walking, instead of biking, until December.

Park officials said trails will open as they are cleared, throughout the coming weeks and months.