A three-hour tour

The view from the top of a stacked-rock wall protecting Woodland Valley Road from the stream that was undercutting the road. (Photo by Violet Snow)

The “Bowl of Doom” is a nickname given by local water scientists to an area on a curved bank of the Stony Clove Creek in Chichester, north of Phoenicia, said Cory Ritz, Stream Project Manager for Ulster County Soil and Water Conservation District (UCSW). Over the years, flooding along the creek has exposed a steep hillside of loose soil and rock that washes into the water whenever it rains. This material tends to settle where the water slows down, right under Phoenicia’s Main Street bridge, contributing to flooding on Main Street during three storms since October 2010.

Ritz spoke during a December 9 tour of Shandaken flood remediation sites, most of them overseen by Ashokan Watershed Stream Management Program (AWSMP), which is funded by New York City Department of Environmental Protection (DEP). Much of UCSW’s local work is also through a contract with DEP. While the DEP’s primary objective is maintaining the quality of New York City’s drinking water as it flows through the upstate area, flood prevention is seen as compatible with that goal.

Advertisement

Local residents have expressed anger at the state and city for the flooding, blaming them for neglecting to maintain streams over the past two decades.

Last December, when Main Street went underwater for the second time in two months, AWSMP began to collaborate with the Town of Shandaken and other government agencies to create a townwide flood mitigation plan. The devastation from Hurricane Irene has made such a plan even more urgent, but it will take months to devise — June is the estimated completion date for the draft — and the actual remediation is expensive. The plan itself will cost $102,000, and individual construction projects in the area have ranged from $5478 to $200,000.

DEP Commissioner Carter Strickland announced on December 7 that the city has committed $7 million to improving flood studies and maps in the west-of-Hudson watershed through a contract with FEMA. This funding is in addition to $2.7 million available for technical support and engineering services to help flood recovery efforts in local partnerships with Soil and Water Conservation Districts.

The state, too, is chipping in, according to Willie Janeway, Region III Director at New York State Department of Environmental Conservation (DEC), who attended the tour. He said the 2012 state budget sets aside $9 million for emergency flood remediation and $20 million for more general assistance to flooded communities.

 

Protecting Main Street

Cory Ritz, left, of Ulster County Soil and Water, and Danny Davis, right, of NYCDEP, address bus tour participants at the Stony Clove remediation site in Phoenicia, where there is now plenty of headroom under the bridge. (Photo by Violet Snow)

Among the sites highlighted on the tour was the area around the Main Street bridge, where 20,000 cubic yards of sediment were removed in the weeks following Hurricane Irene, according to a design by Milone & MacBroom, engineers working for DEP. Through the fall, there were signs that the channel was starting to fill again.

In November, further work was done to reduce the size of the park along the bank, allowing more room for flow under the bridge. A horseshoe of rock, called a crossvane or boulder weir, was placed across the creek just upstream from the bridge, to focus the water’s force in the center, rather than along the fragile banks. The crossvane will also accelerate the flow in an effort to prevent sediment from settling under the bridge, where the water tends to slow down due to backwash from the nearby junction with the Esopus.

Danny Davis of the DEP said the construction may not prevent flooding in an event the size of Hurricane Irene, but it will hopefully protect Main Street in smaller storms like those of last October and December. Part of the agreement with DEC, whose representatives took many months to approve the permit for the work, is that surveys of the site will be conducted regularly to see how effective the modifications have been and how fast the creekbed fills up again. A project is also scheduled to try to address the washing down of sediment from upstream sites, especially the Bowl of Doom.

Scientists believe that before people arrived, the Stony Clove flooded regularly across the area now occupied by the hamlet of Phoenicia, said Davis. Now that Route 214 restricts the creek to a narrow channel, it responds to excess rainfall by eroding the banks and depositing sediment downstream. Until 20 years ago, the town dredged regularly to keep the sediment level low. “Then regulations changed,” said Davis, “but nothing else was being done to prevent flooding.”

When asked why regulations changed, both Davis and Janeway were vague, citing unintended impacts on the environment and on infrastructure. They preferred to emphasize the growing cooperation among government agencies since the August flood.

“I’m seeing the state, city, town, and county working together around a plan and a strategy,” agreed Chester Karwatowski, president of the local chapter of Trout Unlimited, who also attended the tour. “In a crisis, people are anxious about saving their houses, but some of the past practices have caused problems. There are hundreds of private bridges and culverts in the watershed.”

Both public and private structures have often been poorly designed, as in the case of the too-small culverts under the Oliverea Road near the Full Moon Lodge. When the culverts became clogged with debris during the hurricane, the force of the water knocked them out, along with 40 feet of road, leaving a ravine 90 feet wide and 20 feet deep. Not until early December was a temporary bridge completed at the site.

 

Waking up in the river

The night of Hurricane Irene, a group of college students obeyed the suggestion to evacuate New York City by repairing to a house in Oliverea for a hurricane party. Late at night, they failed to hear the sirens and calls for evacuation as the floodwaters rose. The students awoke as the house was floating down the upper Esopus Creek. Luckily, it got stuck at a bridge, and no lives were lost.

Ritz told this story as the tour bus drove up Oliverea Road, where only one of half a dozen bridges survived the hurricane and numerous houses were inundated. At least one homeowner is pursuing the possibility of selling his home to FEMA in a program where the federal agency buys out condemned buildings in flood zones.

A positive outcome of the hurricane, said Elizabeth Higgins, program coordinator at AWSMP, is that “now we have data” to justify funding for flood prevention projects. The agency has submitted an application for a mitigation grant from FEMA to address the situation near Brown Road in Oliverea, where the Esopus has changed course several times, threatening to undercut the road and impacting homes repeatedly since the 2005 flood.

Advertisement

In Woodland Valley, Ritz showed off a successful project, where the construction of a 152-foot stacked rock wall, integrated with plantings of willow and red-osier dogwood, has protected the Woodland Valley Road through three floods since the project’s completion in September 2010. Funding came in the form of an $89,000 hazard mitigation grant from FEMA and $35,075 from AWSMP and Cornell Cooperative Extension. Design and construction were done through collaboration among town, county, and city agencies.

When asked what percentage of such projects built over the last ten years had survived flooding, Ritz said he did not have data, but he thinks most of them have done well.

The bus paused on the Woodland Valley bridge for a look at the remediation done in 2003 to prevent homes from sliding down the gradually eroding bank. The creek channel was diverted, and the bank was sloped and covered with plantings. An unexpected effect, during the 2005 flood, was erosion of the opposite bank, endangering the road and a house. Remediation of that area ensued and held up in all the recent flooding. Davis noted the formation of an unanticipated pond on one side of the site, providing good habitat for wildlife.

The tour ended with a ride down High Street, where several feet of bank have been lost since 2005, including the railroad bed. The rails now rest on a gravel bar on the far side of a deep, narrow channel that threatens a pump house, an essential part of the Phoenicia Water District infrastructure.

What do the scientists and engineers plan to do about this situation?

“We have no idea,” Davis admitted. “It’s overwhelming. But it will be addressed in the mitigation plan we’re working on.”

I hope they figure something out. My house is right on the other side of the road.++