Figure 14. Maximum extent of sediment plume with bucket release rate of 2 percent for Fox Point Reach Central (FPRC) site and Fuller Rock Reach Central (FRRC) site over the 3-day simulation time.

ERDC TN-DOER-E12

July 2000

Figure 14. Maximum extent of sediment plume with bucket release rate of 2 percent for Fox Point Reach

Central (FPRC) site and Fuller Rock Reach Central (FRRC) site over the 3-day simulation

time. Plan view shows release point, channel geometry and maximum concentrations (mg/L)

at 8-10 m (26-33 ft) depth. Vertical section shows distribution of maximum concentrations

(mg/L) over depth along dashed section line shown in plan view. Concentration contours

correspond to ranges in the Newcombe-Jensen (1996) fisheries impact model

the extent of the maximum concentration plume greater than 3 mg/L at 9 m (30 ft) is now

approximately 4.3 km (2.6 miles). As for the case of simultaneous dredging at two sites, there are

only two relatively small locations with concentrations greater than 20 mg/L surrounding the release

sites.

SUMMARY AND CONCLUSIONS: A 3-D hydrodynamic model was applied to the Providence

River Harbor and Channel area to generate a representative set of currents in the Providence River

and Upper Narragansett Bay for input to SSFATE, which then computed the transport, dispersion,

and settling of the dredged material released at selected sites.