DUNEDIN — Engineers warn that it would be extremely noisy. Logistically tricky. And, at roughly $2.4 million, about $1.3 million more than city commissioners expected, expensive.
But Dunedin officials and residents will have to decide in coming weeks whether dredging Cedar Creek and Lake Sperry is worth potentially 20 years of relief from chronic flooding.
The issue has turned controversial as some residents say the entire city has contributed silt and trash that clog the two bodies of water.
Others say dredging would benefit only a few waterfront homeowners who want the city to foot the bill for a naturally occurring phenomenon so they can go boating.
Either way, a consulting firm the City Commission hired in November to study the problem indicates swift action is needed.
"There are going to be impacts to the system eventually if no maintenance is done out there. It's going to a condition that's going to at some point cause stormwater and drainage problems," Joseph Wagner of Taylor Engineering said of Cedar Creek.
The situation is similar at Lake Sperry, which Wagner said has essentially functioned as a citywide retention pond.
"This is a basin that is getting to the point of limited use," Wagner told commissioners during a recent public workshop. "It is getting to its capacity, where any storm of any event will take material into the basin and take it right back out."
The engineer said "there is no doubt in my mind" that the sediment buildup in both bodies of water originated upstream: "This isn't being flushed in from St. Joseph's (Sound). It's coming downstream."
An additional problem at the 4.5-acre Lake Sperry, according to Taylor Engineering, is the original developer's improper installation of seawalls, which allow stormwater to drag silt over the walls and into the basin. Raising the walls, Wagner said, would stabilize them and reduce the need for long-term depth maintenance of the lake.
While Wagner advised that he "would not go forward with this project without dealing with these seawalls," Commissioner Julie Scales noted that they "aren't a city-created problem." Vice Mayor Julie Ward Bujalski, however, said she wanted engineers to research the cost of seawall repairs.
"If you're saying we shouldn't do one without the other, then we need to know what the other is too, whether we pay for it or somebody else," Bujalski said.
Wagner also "strongly" recommended that the city trim mangroves lining Cedar Creek or risk an expensive reconstruction of the stormwater system down the road.
The state and federal regulatory agencies that monitor dredging have indicated that they would grant a dredging permit for the portion of Cedar Creek located west of Bayshore Boulevard for navigational purposes, and the eastern half for stormwater drainage purposes.
Returning the water bodies to 1996 levels, when they were last dredged, would remove six feet of silt, or 24,100 cubic yards, from western Cedar Creek; 4,500 cubic yards from the more shallow and narrow eastern Cedar Creek; and five feet of silt, or 19,300 cubic yards, from Lake Sperry. For comparison, Wagner said, a dump truck holds about 20 cubic yards.
Engineers estimated project duration, from permitting to dredging completion, at 16 months for Cedar Creek and up to 14 months for Lake Sperry. Some homeowners would have to give permission for the city to dredge under private docks or to use their property to either access the narrow straits or store equipment.
City officials, who have already poured roughly $10 million into work farther upstream, said they initially budgeted $1.1 million for the project simply as a placeholder while they awaited scientific findings. Wagner says the city could likely drive down project costs through things like finding alternative silt disposal methods.
Taylor Engineering expects to present its final report to the City Commission by May, after which the city will give residents a chance to weigh in.
Keyonna Summers can be reached at (727) 445-4153 or [email protected] To write a letter to the editor, go to tampabay.com/letters.