Engineers Agree–A Berm WILL Stop the Flooding!
TED–Sometimes dealing with the City of Port Orange is like shoveling water
Ted posted the following to Manager Harden earlier today………………….
The good news in the Pegasus report is that it has confirmed what we knew all along and that is – the 6ft NAVD elevation berm on the west side of the Halifax Canal south of Powers Ave and on the East side of that canal North until it tied in to higher elevations South of Herbert Street as originally designed by QLH and permitted by SJRWMD would prevent flooding on lower Dunlawton Ave.
This conclusion may be found on page 5 of their report;
” In addition, constructing the berm on the east side would have severed the floodplain area adjacent to the Halifax Canal and potentially caused an increase in flood stages upstream of the berm. In other words, constructing the berms along the canal would have effectively created a levee / dyke drainage system to prevent floodwaters from the Halifax Canal from occupying the study area. However, the displaced flood volume associated with the severed floodplain would have caused potential impacts upstream of Dunlawton Avenue, as well as within the study area ”
This is exactly what QLH the Design engineers have said in open meetings and in the attached e-mail to the effect that Dunlawton Ave floods once the Halifax canal overtops its banks because the Dunlawton Ave Drainage Improvements Retention Pond was designed and constructed ” without the influence from the canal as a stand-alone system due to the fact that if the canal overtops its banks, the pond volume is inundated by flood waters from the canal ”
The bad news in the report is their conclusion that containing canal water within the Canal banks in the subject area would cause additional flooding elsewhere in un-specified areas.
Accordingly lest this nebulous un-specified flooding elsewhere be used as a pretext to do nothing beyond studying the matter further I would ask that you cause the following to be provided in support of their ‘flooding elsewhere’ conclusions.
* the exact spot or spots and their respective elevations on the west bank of Spruce Creek Rd north of Dunlawton Ave where Pegasus has advised water would over top that bank, — remembering that the permitted plans provided for the berm along that west bank of the Halifax canal from Dunlawton Ave north to Powers Ave.
* the exact spot or spots and their respective elevations where Pegasus has advised that new or increased ‘upstream’ flooding would occur.
for responsible government – 2016