Master Plan Development - City of Boca Raton

City of Boca Raton Stormwater Management Master PlanDrainage Basin3. Drainage BasinIn general, current stormwater management policies rely heavily on a watershed or drainage basinapproach. Historically, the City has been interested in five major watersheds associated with thefollowing water bodies: The C-15 Canal, the Hillsboro Canal, the E-3 Canal, the E-4 Canal, andthe ICWW. Several drainage basin delineations have previously been made: specifically, thosedone by SFWMD and DEP. In addition, drainage basins were established when the original MS4NPDES permit application was made in the early 1990s. The watershed boundaries do notcoincide with one another. Therefore, with the information currently available, updated basindelineations have been made for the five major watersheds within the City.A. Basin DelineationsSFWMD permits, FDOT and PBC project construction drawings, the GIS coverage of the City’sstormwater system, aerial photographs, terrain elevations, and the LWDD Elevation Map were allused as sources of information to define the five major drainage basins within the City.ICWW WatershedThe ICWW is a tidally influenced water body. Any system that discharges into the ICWW or anuncontrolled tributary of it is considered part of its drainage area. While this is somewhatconsistent with the DEP drainage delineations, it varies from SFWMD and the previous NPDESdelineations. The decision behind the chosen delineation is that the Hillsboro Canal controlstructure (G-56) is west of the E-3 Canal. This means that, like the ICWW, the Canal east of thestructure and any tributary discharging into it, are tidally influenced; essentially one with ICWW.The ICWW drainage basin includes those drainage areas that discharge into any canal, or portionthereof, that is tidally influenced. Similarly, areas discharging to the C-15 downstream of itscontrol structure (S-40) are considered part of the ICWW drainage basin.E-3 WatershedThe E-3 Canal discharges to the Hillsboro Canal, however, its water level is controlled by acontrol structure (CS No.16) near the confluence with the Hillsboro Canal. The E-3 Basinincludes all the drainage areas discharging into LWDD L-43 to L-50 Canals, west of MilitaryTrail, or those that discharge directly to the E-3 Canal south of Yamato Road.E-4 WatershedThe E-4 Canal also discharges to the Hillsboro Canal downstream of the G-56 structure. Areasdraining to the portion of the E-4 Canal south of the salinity structure are in the ICWW drainagebasin. The E-4 drainage basin includes all the drainage areas that discharge into LWDD L-40 toL-46 Canals, east of Military Trail, or those that discharge directly to the E-4 between ControlStructure No. 15 (near the City’s northern limits) and the salinity control structure north of GladesRoad.L/bocaswmp/a6016.01/InterimReport 11-27-07/r02Page 9MOCK•ROOS