River issues, a regional perspective

Takin’ it to the creeks

Dredging and ‘dozing the depths

By SANDY LONG

sandylong@riverreporter.com

UPPER DELAWARE — The impact of flooding on human life can be profound, displacing or destroying buildings, bridges and roads, even causing loss of life. Following recent flooding in the Upper Delaware River region, public outcry for flood mitigation strategies has intensified, with some calling for immediate dredging of creeks and streams that swelled to treacherous levels.

The thinking behind such measures is simple: get the stuff out of the channel so the water can flow freely. While those whose properties lie within floodplains are understandably eager to see such measures taken, others are saying that dredging isn’t the answer. Although both New York and Pennsylvania have issued emergency permits for removal of blockages that occur when trees and other large items are pulled into waterways, dredging is a different matter.

Dredging up danger down the line?

Nationally based organizations are saying it; federal and state agencies are admitting it; even local officials dealing with intense public pressure to the contrary have begun to agree. As a long-term solution, dredging doesn’t work.

In addition to water, rivers and their tributaries mobilize sediments and transport them to new locations. Altering rivers and tributaries by dredging to remove rocks and gravel enables water to move more swiftly, with even greater force and sometimes more devastating consequences. Ultimately, it moves the problem down the line, making it someone else’s potential nightmare.

“It’s a gun barrel effect,” said Jack Isaacs, Habitat Protection Manager for New York State Department of Environmental Conservation (DEC). “When you smooth out the bottom of a creek and push up the sides, you essentially make a chute for the water to blast through. That can be devastating to downstream communities.”

Following the flooding, the DEC made emergency permits available for flood-related damage. Many affected towns began removing trees and other obstructions from the creeks. Near the hard-hit towns of Youngsville and Livingston Manor, NY, heavy machinery was used to remove debris. And while most of the work remained limited to such measures, some resulted in the creation of new gravel embankments resembling small dikes on the sides of the streams.

Nathaniel Gillespie, Fisheries Scientist for Trout Unlimited (TU), performed extensive research on the waterways within this area during his tenure as Catskills Coordinator for TU from 1999 to 2002. Based on his findings, Gillespie agreed that dredging is a short-term fix. Making a section of stream straighter and deeper increases the stream’s power and erosive force. That translates into loss of property unless streambanks are continually reinforced with large rocky fill called rip-rap and rock walls—an expensive, ongoing cycle. Gillespie added, “Dredging ‘unzips’ the tightly packed stream bottom and creates a source of loose gravel. With the next high water, the loose gravel fills the channel downstream, blocks bridges, and often causes the stream to carve a new path.”

In addition, dredging can harm aquatic life, said Don Hamilton, Natural Resource Specialist for the National Park Service, Upper Delaware Scenic and Recreational River, who noted that dredging can cause degrading in some places, aggrading in others, along with sedimentation, turbidity and habitat degradation.

Not just about trout

In a region that survives, in part, on the economic influx generated by its exceptional fly-fishing, the role of trout has undoubtedly become linked with human welfare. Destroying trout habitat has an economic impact on human well-being.

Conversely, human activities can create an imbalance in the process of erosion and deposition in tributaries. As development continues to accelerate throughout the region, impervious surfaces such as roads, parking lots, sidewalks and roofs multiply and increase storm water runoff. “All of these activities contribute to higher waters flooding with more power with less space to spread out,” Gillespie said.

In an increasingly familiar refrain, some have characterized the dilemma as an issue of “trout versus people,” when it comes to deciding about dredging. It’s a frustrating over-simplification of a far more complex set of issues for Town of Rockland Supervisor Pat Pomeroy, who believes the outcry for dredging is the result of misinformation. And while she’s eager to see immediate relief come to her town, she’s pushing for a flood plan that addresses a broad range of long-term solutions.

Don’t doze?

The United States Army Corps of Engineers (USACE) has been involved with flood remediation efforts in the region. Although potential solutions vary, Brian Mulvenna, USACE’s project manager for the Upper Delaware Basin, said that his agency views dredging as a financially impractical strategy with limited short-term benefits. “When you put a bulldozer in a stream, it destroys habitat and relocates the problem,” Mulvenna said.

The USACE plans to perform a detailed study in conjunction with state agencies and local officials, but budgetary restrictions have delayed the work. In the past, the USACE built dams and levees with greater frequency. Today, the agency has shifted its emphasis to more sustainable solutions like stream and floodplain restoration. And while that might not be easy to accept, it is echoed by groups grappling with these issues.

Long-lasting solutions

During the past year, the Friends of the Upper Delaware River (FUDR) organization developed a comprehensive scientifically based proposal focusing on floodplain and tributary restoration in the Upper Delaware River basin. President Craig Findley said FUDR seeks initiatives that would reduce the impact of floods on residents, as well as the region’s ecology and fishing-related economy. “We have deep empathy for the losses people incurred. We need long-term solutions with all stakeholder groups involved,” Findley said.

FUDR advocates that solutions should include a fair-market buyout program for those living within flood plains, a reevaluation of the permitting regulations pertaining to sewage treatment plants, power lines and pipelines and the reassessment of policies pertaining to future development within flood plains. FUDR has also called for the development of a comprehensive flood plan.

Floodplains an important factor

Flooding is a fact of life. Delaware Riverkeeper Maya van Rossum, head of the Delaware Riverkeeper Network, which advocates for the river and its streams, said, “Flooding is not avoidable. When waterways flood, they need access to their floodplain. We need to invest in removing structures from the floodplain, restoring the floodplain to natural function and relocating our homes and businesses to dryer upland grounds.”

In January, Gillespie delivered a presentation on flood relief options in Livingston Manor. Then and now, he believed, “The most cost-effective, long-term way to reduce flood damage is not to try to wrestle with the region’s streams and rivers by reshaping their channels, but instead to give the rivers room to flood safely on their floodplains.”

“People are in pain and rightfully want answers to why this happened,” said Gillespie. “Everyone in the region wants the same things—to protect people from the awesome power of water, to keep homes as safe and dry as possible and to avoid destroying the environment in the process. Instead of fighting the rivers, we must give these waters the room they will take with or without our permission.”