Big Fishweir Creek still unnavigable 10 years later
When The Resident launched its first issue in January 2007, the lead story on the cover focused on sediment runoff in Little Fishweir Creek, an urban tributary of the St. Johns River, approximately four miles south of downtown Jacksonville.
Neil Armingeon, St. Johns Riverkeeper at the time, worked with the City of Jacksonville’s Environmental Quality Division to discover a water main break on Eloise Street was the source of increased turbidity in the creek.
At one time, Fishweir Creek was a deep waterway, but the buildup of sediment over the past 30 years has rendered it unnavigable.
“This tributary is tidally influenced,” said Amanda Parker, United States Army Corps of Engineers (USACE) Public Affairs Specialist. “The contributing sub-basin to Big Fishweir Creek has been urbanized predominantly with residential land use, much of it occurring prior to promulgation of storm water regulations. Therefore, limited storm water management has been implemented in the sub-basin, resulting in sediment deposition in the creek. Urbanization included encroachment along the banks of the creek. Over time, sediments transported by storm events have covered the natural creek bottom. The sediment deposition and encroachment from urbanization have reduced the natural habitat in the creek and along the creek banks.”
The Corps began a study in 2007 to restore Big Fishweir Creek, but 10 years later, the creek is still not navigable; herons and egrets are often seen standing in just a few inches of water as they forage.
According to Parker, the 10-year delay in restoring the creek is based on funding, both from the federal and non-federal side. At one time, the total cost of the project was quoted as $4.8 million, with $3 million to be federally funded and $1.8 million from state and local sources.
In July at the groundbreaking of the RiverVUE waterfront apartment complex, District 14 Councilman Jim Love announced the Corps was looking at the restoration project again, which could occur as early as 2019.
The overall goal is to restore a healthy aquatic habitat in the creek, Parker said. The project will include the removal of anthropogenic sediment accumulations, restoration of habitat for listed species, reestablishment of intertidal and sub-tidal benthic communities, removal of exotic vegetation, restoration of submerged and emergent aquatic vegetation functions, and restoration of wetland habitats.
The sediment that is targeted for removal consists of accumulated anthropogenic material in the stream bed. Removal of approximately 32,000 cubic yards of sediment will create two channels at the mouth of Big Fishweir Creek that will converge to form one channel heading upstream to the project limit.
The target depth of the channel(s) would be four to six feet below mean low water in the lower and central portion of the stream, and at least four feet in the upper channel. The pattern of the channels near the mouth of the stream would be routed around the proposed created marsh island before joining the St John’s River.
Dredged material from the channels would constitute the foundation of the marsh island, and is expected to encompass some 2.3 acres at the mouth of Big Fishweir Creek. The material will be encased in geo-textile tubes that will be configured to form the foundation of the island. In addition, sand substrate from the upper portion of the stream will be used to cap the newly formed island, and will provide the proper medium for vegetation plantings. A sediment trap will be dredged at the base of the island to manage sediment loading by controlling current velocity, thus decreasing future maintenance of the stream.
By Kate A. Hallock
Resident Community News
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