Standing water conditions have been observed along the swales and shoulders of Boatman Street at the intersection with South Military Trail, and at the west end of Boatman Street over the roadway and on private property following minor rainfall events.
Area Photos:Existing Conditions:
Responsibility for maintenance of Boatman Street is listed as “Private” in Palm Beach County roadway data. The private residence at 4445 Boatman Street appears to be the lowest lying area within the drainage boundary. The bank property located on the south side of Boatman Street has minimal surface water management facilities. Runoff generated on the northern portion of the bank property primarily sheet flows directly into Boatman Street and, ultimately, into the area surrounding the private residence located at the east end of the roadway.
GIS data does not show existing swales, catch basins, or other drainage system components along Boatman Street. LiDAR data shows the lowest centerline elevation at the east end of the roadway, furthest from Military Trail. The highest point is at the intersection with Military Trail, creating the possibility that runoff from some portion of Military Trail is contributing to the issue. The basin is bounded on the east by an undeveloped parcel at a slightly higher elevation issue. The basin is bounded on the east by an undeveloped parcel at a slightly higher than Boatman Street, preventing overland flow from leaving the drainage area in that direction.elevation
SFWMD Surface Water Management (SWM) Permit No. 143-87-S (Application No. 09257-2 for Babbsco Auto Paint & Body Shop) covers a property on the north side of Boatman Street, but no receiving body is listed. SFWMD Environmental Resource Permit (ERP) No. 50-10890-P, Application No. 150814-4 issued to the Florida Department of Transportation (FDOT) District 4 covers Military Trail adjacent to the area of concern.
From review of the construction plans for Military Trail, the design of the FDOT drainage system anticipated runoff from the westernmost 100 LF of lots adjacent the roadway. A hydraulic and hydrologic analysis was conducted to establish approximate drainage boundaries for the contiguous drainage area and quantify the anticipated volume to be released to the Military Trail system. To facilitate discussion with FDOT, drainage calculations were prepared to quantify a peak flow rate generated by the area included in the existing Military Trail drainage boundary. The calculations compare the existing peak flow to the increase anticipated with the inclusion of additional area from along Boatman Street.
The schematic design for Boatman Street includes installation of catch basins for stormwater collection and reinforced concrete drainage pipe for conveyance. Restoration of swale grades to direct stormwater to the catch basins is recommended to reduce the occurrence of standing water. Exfiltration trench along the main trunk line will assist with attenuation of stormwater and reduction of volume prior to discharge.
The proposed drainage system is located along the north side of Boatman Street to minimize potential impacts to large trees along the south road shoulder. The main trunk is shown close to the edge of pavement to reduce the width of pavement disruption and replacement, and allow for construction of the proposed improvements within a single lane of the roadway. Coordination with residents will be necessary as this street provides access to several residential lots. An open travel lane will minimize disruption of access. Milling and overlaying both lanes of the roadway at project completion will provide the best quality for the finished driving surface.
The Village should consider requiring any future development within the vacant property east of Boatman Street to pass through storm water runoff from properties along Military Trail to the LWDD L-11 Canal.
Permitting through FDOT and connection to the existing system along Military Trail is recommended. Connection to an existing catch basin at the southeast corner of the intersection of Boatman Street and Military Trail is proposed, with a control structure to be installed prior to the point of connection to assist in regulation of the discharge rate and to promote percolation of collected runoff into the subgrade.
Discharge from the proposed system will be received by the existing Military Trail drainage system. Approval by the Florida Department of Transportation will be required prior to construction.
The estimated cost of this project is $155,000. A detailed Opinion of Probable Construction Cost, Schematic Design drawing, and drainage area exhibit are attached.
Construction Plans and Drainage improvement