Updated 08/29/06
Intracoastal Waterway, Miami-Dade County – Phase I
Summary of Work Performed
August 2000
We have essentially completed Task
I-A (Data Collection) and Task I-C (Establishment of Long-Term Requirements),
based on all information presently available.
Specifically, we have reviewed all available sediment chemistry data for
the Dade County project area (Task I-C.1), including data recently obtained by
the Jacksonville District, U.S. Army Corps of Engineers’ (COE) in their recent
comprehensive channel sediment survey. However, additional COE core boring logs
and grain-size data expected from the same sediment survey, although included
in the same contract, was not obtained and will not be available to assist in
the present planning effort. Absent
this data, we selected appropriate sediment sampling locations for our planned
sampling program, scheduled for the week of September 11th. We compiled and reviewed all available
Jacksonville District, U.S. Army Corps of Engineers’ (COE) archival dredging
records and channel surveys and projected a preliminary estimate of future
dredging and material storage requirements (Task I-C.2) for the 10-ft project
segment within Dade County. We completed our analysis of the final data set
from the Jacksonville District’s three line survey of the entire ICWW,
including the Dade County segment south to the Monroe County line and, based on
the results of this survey, updated our preliminary projections for the 10-ft
project segment and extended our projections to encompass the 7-ft project
segment as well. We have inventoried
all existing easements within the project area based on our review of relevant
COE Real Estate maps and Control Data sheets for the Intracoastal Waterway,
Jacksonville to Miami and Miami to Key West (Cross Bank), and 1994 FIND
blueline aerials, evaluated these easements with respect to their potential
material storage capacity (Task I-C.3), and calculated the project area’s
existing material storage capacity (Task I-C.4). However, given the
concentration of existing shoaling around Baker’s Haulover Inlet and the
potential for beach placement of appropriate channel sediment in this area,
final definition of operational channel reaches must wait until we receive the
data from our sediment sampling program to delineate the channel segment
containing beach quality material, as well as to characterize sediment
conditions throughout the 7-ft project segment for which no reliable data is
presently available.
The results of Task I allowed the
preliminary evaluation of likely material management concepts (Task II-A) and
the identification of 63 additional candidate sites (Task II-C) based on an
office review of 1994 NAPP color-IR aerial photography, USGS 7.5-minute
topographic quadrangle maps, Comprehensive Plan Future Land Use maps and U.S.
Department of the Interior wetland inventory maps. We are proceeding with the evaluation of these candidate sites
(Task IV). To update each candidate site’s present land use, we obtained
current (1999) Dade County tax aerials for all candidate sites. Through review of these aerials, we
eliminated 11 candidate sites with obvious land use conflicts (i.e., recent
development) not shown in the 1994 aerials, and thereby reduced the number of
required candidate site inspections.
During the weeks of April 10th and April 24th, a
engineer-biologist team inspected all remaining candidate sites as well as the
two existing sites with some potential for continued use (Task III). We are now completing the mapping of land
use and vegetation communities on each site to Level 3 of the Florida Land-Use
and Cover and Forms Classification System (FLUCS) (FDOT, 1985), based on the
1999 Dade County aerials and proceeding with each site’s evaluation (Task IV)
under the full standard set of engineering, operational, environmental,
socioeconomic, and land-use criteria. We have thus far received over 40
candidate site maps from our biological and mapping subcontractor and are now
drafting site data summary sheets and narratives for these sites. We are now
preparing all materials to present the results of Task IV at the next round of
Technical and Citizens’ Advisory Committee meetings/public workshops in
November.
Following up on an earlier meeting, Taylor Engineering staff met on August 21st with Susan Markley of the Metro-Dade Department of Environmental Resources Management (DERM) to review the earlier discussion on our present list of candidate sites and recommendations for additional candidate sites. Following this brief meeting, Taylor Engineering staff made initial visits to several potential sites along the Miami River, revisited the three candidate sites on Virginia Key, and located several abandoned former powerboat manufacturing sites in an area known as Thunder Alley, just west of Dumbfoundling Bay. We are now preparing to formally inspect these sites with an engineer-biologist team, as well as at least three additional sites east and southeast of the former Homestead Air Force Base suggested by DERM.