Bethany dam project creates concern

“We will not cause flooding in other areas to solve problems in Bethany Beach.”

It was important enough of a statement that Bethany Beach Town Council Member and Drainage Committee Chairman Harold Steele felt compelled to reiterate it on numerous occasions and in numerous ways in recent weeks, including at the town council meeting Jan. 21.

The problem for the town is the flooding that occurs during heavy storms, specifically that coming from the Assawoman Canal down the town’s Loop Canal and into its streets. The problem others have seen is the potential negative impact of the town’s proposed plan to reduce that flooding with the use of an inflatable dam.

Steele worked hard in recent weeks to reassure property owners in nearby towns and communities that the proposed dam would not be put into place without plenty of chances for input from those residents, as well as much scientific study and formal approval by state agencies.

The bottom line: “We will do whatever we can to solve the problems to everyone’s satisfaction. If we can’t, it won’t happen.”

Much of the activity of the Drainage and Flood Committee for some months now has focused on the potential impact of the inflatable dam, both positive and negative.

At the committee’s December meeting, Steele had presented preliminary findings from an engineer employed by the town regarding some potential flooding problems the dam might cause in Ocean Way Estates, just on the other side of Assawoman Canal from the town and near the proposed location for the dam.

Those findings had suggested the potential for increased water intrusion from the canal onto at least two properties in the community in the case of a flood of the magnitude from the 1998 storm, the level for which the dam project is designed.

Steele had said mitigation options would be considered for those property owners, as well as any others impacted by the dam, but he also emphasized that the consideration of such impact was key in even deciding whether or not to move forward with the project.

All that some property owners in Ocean Way Estates needed to hear was that there was a potential risk for increased flooding to those two properties. They then flooded Steele with telephone calls, and a small group attended the committee’s Jan. 20 meeting to air their concerns.

“We will not do anything to damage your properties or to create problems for you,” Steele told them at the top of the meeting.

He also said he planned a meeting with representatives of Savannah’s Landing that very afternoon, to address some of the same concerns.

Steele noted for the concerned property owners that the town was still in the very early stages of planning the dam solution, with many stages of permitting ahead — all of which he said would have to be preceded by public hearings, the record of which would be available to permitting boards before the plan was given any go-ahead.

The process is a slow one, with plenty of time for public input and information, Steele emphasized, saying, “I’m just hoping to get this done in my lifetime.”

Asked whether solutions other than the dam had been considered, Steele said the notion of pumping floodwaters out into the ocean had been considered but dismissed as ineffective. As to whether the impact to two properties might affect others in the community, Steele noted that any impact (i.e., on insurance rates) would be for the affected properties alone and not an entire development.

Town Manager Cliff Graviet pointed out that the project was not even to the design phase yet, and “DNREC (Department of Natural Resources) and the Corps (Army Corps of Engineers) will ask the same questions” as the concerned property owners when considering permitting the project.

Graviet confirmed that other solutions for flooding in Bethany Beach had been considered. “This was determined to be the best method — not the best cost; it has nothing to do with cost.” (The estimated cost, when considered several years ago, was $1.3 million, he said.)

Indeed, the Corps, he said, had itself considered and rejected the idea of a swinging flood gate as likely to cause deleterious “scouring” and had instead recommended the inflatable dam to the town.

“This is guaranteed. If it causes problems that cannot be resolved to your satisfaction and to our satisfaction, it will not be done,” Steele said.

Asked to quantify the impact of the dam, Steele noted that engineer Tim Ruga had predicted a run-up of several inches in height, up to 10 inches maximum, in the case of a flood event similar to the 1998 storm. He emphasized that Ruga’s preliminary findings had indicated increased water on the properties in question and not flooding in the homes on those properties.

“This is a long way off,” Steele concluded. “We will resolve the issues to everyone’s satisfaction before we do anything.”

“We’ll all be very well informed and much older,” Graviet chimed in.

Committee members then moved on to address concerns about flooding and drainage problems at Tingle Avenue and Evans Road. Public Works Director Brett Warner noted that attempts had been made to find a solution to flooding on Tingle Avenue itself, to no avail. The area, he said, simply lies too low and was graded poorly. The situation might be somewhat improved during the regular repaving of the area, set for the spring, he said.

The Evans Road area had also been subject to a number of efforts to improve drainage, Warner said. The tide-flex valve installed in the vicinity is one of those in the town where the drop from its high section to the drainage section was never high to enough to allow the valve to work, he said.

The road was graded in a way that created a large hole in which water collects, Warner added, and the grown-over swale near the rear of the properties has only served to contribute to the problem. However, he said with regarding and proper elevation of the drainage pipes in the area, it could be drained.

Warner said the town would likely be returning to the use of traditional flap gates on those pipes and an increased maintenance schedule to ensure they drain effectively, but he noted that the area was still being surveyed. In the end, he said, there was “no easy fix to the drainage issues. It’s going to take some doings to drain Evans Road completely.”

Town Council Member Wayne Fuller requested an update on the status of drainage problems in the Canal Drive area of Sandpiper and Sea Breeze. Warner said he believed regrading the drainage ditch would improve drainage, but again said a survey was needed to confirm the effort would work. He said two or three days of work had already been done by town employees in an effort to improve the drainage there.

Warner said resetting of drainage pipes in the area would also need to be done, while Steele noted that the area was still a ways down on the town’s list of drainage priorities. Currently, the top of that list is the Pennsylvania Avenue area of the town, and that was indeed the main issue on the committee’s agenda for the day.

Lee Bayle, a resident of the Fifth Street and Pennsylvania Avenue area, requested information on efforts to address drainage there. Alan Kercher of Kercher Engineering Inc. (KEI) confirmed that the area had been surveyed and work was being performed on a conceptual design and calculations.

“There is no way a normal piping system will work there,” KEI representatives said.

Instead, KEI is working on a proposal for a storage and pumping system, to be placed underground near the Loop Canal.

Kercher noted that the system is intended to provide relief for a “two-year storm,” one which dumps up to 3.5 inches of rain on the area, rather than a 50-year storm. “This approach has worked in other communities,” Kercher noted.

The system would involve a series of pumps and a collection area, possibly utilizing the Loop Canal (with perhaps some additional berms installed) and/or a large subterranean storage chamber. The storage chamber would allow a quick influx of rainfall to be gradually discharged over time.

Kercher said water-quality standards for such a storage facility would need to be addressed with DNREC. He estimated the system would require a 3,000 gallon-per-minute pump with such a storage facility or an 8,000 gallon-per-minute pump if no such storage were provided. The system would need regular maintenance, regardless, he said.

Kercher also noted that a solution of pumping floodwaters into the ocean had been considered by the town’s previous engineering firm, DBF, but the costs were deemed to be “astronomical,” with a filtering system and a large amount of space required. Such a system would also have to reach as much as an additional mile to the ocean after the proposed 50-year beach reconstruction project in the town was completed, it was noted.

Committee members pointed out that there needs to be a cost/benefit analysis once KEI has provided a cost estimate for the project. The system would provide no protection against a “moderate nor’easter,” it was noted. But emphasis was placed on the hazards of regular flooding to health, structures, evacuation efforts and access to emergency vehicles.

Kercher said the town’s planned bladder dam would also potentially provide additional storage for floodwaters in the Loop Canal, by keeping the canal’s water level lower in the event of such a rainstorm.

He said KEI’s work on the project would proceed to a detailed system analysis stage next, before entering the biddable stage that would include drawings and cost estimates. The analysis will include a detailed look at runoff on a house-by-house basis, KEI representatives said.

Kercher said that if the committee believes the preliminary design for such a system looks good, the firm would then need to obtain agreement from the town to proceed with the design drawings and then contract documents. The work is currently being done under a purchase order from the town.

Kercher noted that he had consulted with Ruga as the town’s consulting engineer on the bladder dam project, to get the best benefit of his expertise.

Steele added that, in yet another engineering loss for the town, Ruga plans to move out of the country in the coming weeks. However, he said Ruga believed the project had been taken as far as it could with a consulting engineer and was at a stage where an engineer for the construction phase would be the appropriate person to handle the project.

“He’s done just about everything he can do,” Steele said of Ruga.

Steele then recommended the town make a decision on hiring just such an engineer to continue the work on the bladder dam project, and committee members unanimously agreed to make that recommendation to the town council.

Finally, Steele took the opportunity to congratulate the committee on their recent work. “We’ve accomplished an awful lot,” he said.