Weather, geese complicate Cannon Rd. wetlands project
A large Sussex County drainage and wetlands restoration project north of Millsboro faced challenges that seemed to take a page from the Bible, as floods, dry weather and a massive flock of snow geese complicated work and drove up costs.
Project engineer Hans Medlarz recounted the issues at the Jan. 14 Sussex County Council meeting as he sought approval to close out the $12 million project, effective Nov. 15, and approve budget increases for unexpected costs and reductions for materials costs that were less than projected. The request was approved 5-0.
“We had the wettest year on record in Delaware, and we probably had the biggest snow goose invasion in our constructed wetland. Just in one night, they destroyed $100,000 worth of plants and just wiped it out,” Medlarz said.
Crews planted three varieties of grasses in the wetlands, completing work in one day in November 2023, Medlarz said. Within 24 hours, a huge flock of snow geese consumed one variety, which had to be replanted.
Heavy rainfall, which included a downpour totaling 7 inches of rain in one 24-hour period in February 2024, flooded Cannon Road, a problem the project was designed to correct.
Later in the year, the site was hydroseeded, and shrubs and trees were planted.
“Then we hit the driest fall in a really long time, which prevented us from having germination,” Medlarz said. “That cost us another $100,000.”
The county had to hire a contractor to truck in water to save the plantings, at a cost of $40,000, he said. The extensive hydroseeded area failed to reach the required 70% germination rate, and the site had to be reseeded.
Those fowl and weather problems were responsible for much of the $453,284 in additional costs for the project, Medlarz said. He noted that credits from lower-than-projected costs of other items offset $368,562 of the unexpected expenses.
The Cannon Road-Inland Bays Road drainage improvement and constructed wetlands project began in February 2023. Work was completed in November last year, several months later than originally expected, as the county made improvements not included in the original scope of the work, Medlarz said.
The project includes a large swale and stormwater system to drain and collect water from the spray fields and Cannon Road, and flood remediation measures were added along Cannon Road and Friendship Road. An elevated wetland area was added to treat effluent and rainwater.
The project includes a large swale and stormwater system to drain the wastewater treatment plant’s spray irrigation system. It is intended to reduce runoff to Guinea Creek and limit flooding along Cannon Road and the plant's spray irrigation fields.
“I would put good odds on we will never overtop Cannon Road again, with the measures that are in place today,” Medlarz said Jan. 14.
