Standing water conditions have been observed covering the roadway at the intersection of Todd Street and Military Trail during minor rainfall events, as well as along the shoulders and across driveways on the north and south sides of Todd Street.
Palm Beach County roadway data lists maintenance responsibility for the roadway as “Private”.
Existing valley gutters collect runoff in the roadway shoulders, but no point of outfall is apparent in the GIS data. LIDAR data shows two low points along the roadway centerline, with the lowest elevation at the west end of Todd Street at the intersection with Military Trail. The basin is bounded on the east by an undeveloped parcel having a slightly higher elevation than Todd Street, preventing overland flow from leaving the drainage area in that direction.
SFWMD SWM Permit No. 50-01989-S for Discount Auto Parts #120 (Application No. 890810-4) was issued to Gilbert, Steinman for the property at the northeast corner of Todd Street and Military Trail, and indicates that runoff from that property will be retained on-site. 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 FDOT drainage system was designed to accept runoff from the westernmost 100 LF of lots adjacent the roadway. A hydraulic and hydrologic analysis establishes approximate drainage boundaries for the
contiguous drainage area and quantifies 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 amount anticipated by the inclusion of additional area from along Todd Street.
The schematic design of proposed improvements for Todd Street includes installation of catch basins adjacent to the low points of the road centerline. A main trunk installed along the north side of the roadway will convey stormwater from the east end of the road westward to the intersection of Todd Street and Military Trail. Exfiltration trench will help manage discharge rates and promote percolation of stormwater into the subgrade.
Construction along the north side of the roadway should minimize conflicts with existing trees and power poles along the south side of Todd Street. Installation of the trunk line close to the north edge of pavement will limit removal and replacement of the existing pavement and allow for a single travel lane to be kept open throughout most of the construction. Following installation of the exfiltration trench and trunk line, the roadway surface should be restored to the original crowned cross-section. The schematic design shows replacement of valley gutters. Both lanes of the roadway will be milled and overlaid at project completion to provide a smooth finished surface for vehicle travel.
The Village should consider requiring any future development within the vacant property east of Todd 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. Discharge from Todd Street will be conveyed via overland flow to an existing inlet on the east side of Military Trail just north of the intersection with Todd Street. The existing pavement and sidewalk at the northeast corner of the intersection may have to be reworked to provide a smooth transition to the existing flow line along Military Trail.
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 $185,000. A detailed Opinion of Probable Construction Cost, Schematic Design drawing, and Drainage Area exhibit are attached.
Construction Plans and Drainage Improvements