The Deep Lagoon Watershed is located in the southwestern area of Lee County. This watershed covers an area of approximately seven square miles. The north boundary of the watershed is approximately McGregor Boulevard (CR 867), the east boundary is near Winkler Road, the south boundary is Summerlin Boulevard (CR 869)/Florida Power & Light grade and the west boundary is a combination of Pine Ridge Road and San Carlos Boulevard.

The Deep Lagoon Watershed originates at its confluence with the Caloosahatchee in Section 20, Township 45 South, Range 24 East. The main conveyance and several tributaries are old IDD canals. The Deep Lagoon Watershed is surrounded by the Whiskey Creek Watershed to the north, the Hendry Creek watershed to the east and Cow Creek to the south. West of the western boundary there are several separate ditches or canals that serve small unnamed drainage areas.

This watershed was not studied in the 1979 Johnson Engineering "Water Management in Lee County" report. The boundaries were modified through the Lee County Surface Water Management Master Plan (LCSWMMP) effort from the original Smally, Wellford and Nalven delineation. Further minor changes may be necessary as development occurs near the boundaries. There are interconnections with Hendry Creek, Cow Creek and coastal drainage areas. These direct interconnections to adjacent watersheds create situations where intense localized rainfall can create significant temporary shifts in watershed boundary division lines. The boundary was determined through a combination of actual field reconnaissance, USGS quad sheets, Lee County one foot contour maps and Johnson Engineering in-house data, both historical and current.

The Deep Lagoon Watershed boundary map is located on page 43-W3. It delineates the overall land boundary. Data for structures along the channel are shown on page 43-WM in the Appendix. The stationing shown on page 43-WM relates to both the flood profile and the structures. The structural facilities are shown in the relative area of their actual location. Limitations of scale do not permit structures to be shown at their exact locations on the ground. This map is intended for general information only. Lengths and widths of structures should not be determined by scaling the symbols shown.

IDD Canal F crosses the eastern watershed boundary. The actual boundary moves or varies, dependent on the antecedent conditions and the particular rainfall's regional distribution. A canal system exterior to this watershed interconnects with the Summerlin Road ditches and the Canal C system. Culvert connections also exist across the south boundary of this watershed. Other situations like this may exist along the boundary. Minor boundary changes may be acceptable if general boundary perpetuation is maintained and downstream facilities can accept the runoff.