Community Budget Issue Requests - Tracking Id #1165FY0001

River Oaks Drainage Study












Floyd Johnson, City Manager


City of Fort Lauderdale











Project Title:

River Oaks Drainage Study

Date Submitted:

2/14/01 9:13:33 AM












Steven Geller














Statewide Interest:

This project meets the objectives of the Florida Water Resources Act.













City of Fort Lauderdale


Hector Castor


100 North Andrews Avenue

Contact Phone:

(954) 761-5240



Fort Lauderdale 33301































Service Area:

Government Entity
















Project Description:








(Include services to be provided)There are substantial drainage problems in River Oaks between SW 22nd and 24th Streets. and between SW 17th and 19th Avenues.  Heavy street and private property flooding caused by development has disrupted the natural drainage characteristics of these low lying lands.  The natural drainage destination is the Osceola Canal.  This canal has been severely stressed in that it is also the receiving waters for run-off from the Interstate system (I95 and I595) and the western portions of the International Airport.


Drainage complaints received in different areas of the River Oaks neighborhood during the past eight years call for different solutions.  Some may be resolved by utilizing ordinary solutions that have been commonly applied throughout the City (e.g. swale reclamation, exfiltration trenches or gravity drainage wells).  Other problem areas  emanate from unusually severe flooding resulting from causes of a more complex nature.  Such flooding has occurred at a frequency of about three times a year over the past five years.  


Flooding within this area may be attributable to several factors, the most obvious of which is its generally low elevation of about 3 feet above the National Geodetic Vertical Datum (NGVD).  This area currently drains through a gravity storm water collection system that outfalls at the Osceola Canal.  The canal's normal high waters have been surveyed and found to be only three to six inches below the general area elevation.  Further upstream, the Osceola canal receives storm water from a large basin located south of SR 84, in the vicinity of the Fort Lauderdale Airport.  During periods of very heavy rainfall, it is suspected that a deluge of storm water from the basin south of SR 84 causes the canal to rise above the elevation of the River Oaks neighborhood.  In that event, water from the canal could back up through the existing storm water system and be a potential cause of flooding in the neighborhood.  Should high tide occur in conjunction with the heavy rainfall, then it is certain that conditions would be further aggravated.  No precise measurements of the canal's elevation at times of flooding are yet available due to the infrequent and somewhat sudden occurrence of the flooding.    


Controlling back flow of canal water into the neighborhood during periods of high tide and heavy precipitation normally takes the form of a control device at the discharge end of an outfall.  We would normally suggest the installation of a "pinch" valve device that effectively seals off the end of the outfall from the receiving waters.  However, current "pinch" valve technology requires significant back pressure to over come the control device (open the pinch valve flaps) to allow forward flow of run-off into the canal when the level of surface waters recedes.  The very slight differential between the average ground elevation in River Oaks and the level in the Osceola Canal precludes the use of this technology because there would not be sufficient head pressure to open the "pinch" valve until the standing water in the surround streets reached a least a foot above the level of the canal.


One alternate approach is to construct a large pump station with sufficient capacity to discharge the quantity of surface runnoff collected in the basin.  A pump station would elevate and discharge storm water to either the Osceola canal, or the South Fork New River, and would enable isolation of the area from the effects of reverse flow from either of those two water bodies.  This would come at significant cost, likely about $650,000, and with a number of significant drawbacks.  For example, pump station operation is dependent upon the supply of electricity, which is often lost in major storm events.  In such events, emergency operations attention must be dedicated to the City's wastewater pumping facilities.  Maintenance costs associated with the operation of a pump station are also quite high.  Another approach is for the City to selectively purchase low lying properties within the neighborhood and create a retention area that can accept the storm water generated within the neighborhood (possibly in conjunction with Broward County's initiative to preserve park/ environmentally sensitive lands).  Once a retention area is created, the connection to the Osceola canal could possibly be eliminated, again possibly enabling isolation of the area from the effects of reverse flow.  In any event, further studies will have to be undertaken in order to verify the feasibility and impact of these and other possible solutions. 


Due to the complex nature of the required analysis, and the lack of in-house resources currently available to dedicate to such an undertaking, we are planning to negotiate a task order for the further study of this area with the City's next General Civil Engineering Consultant.  We are currently in the process (under CCNA) of negotiating with a top-ranked firm to serve in that role, and expect to present a recommendation in that regard to the Commission in the very near future.  As soon as a General Civil Engineering Consultant is under contract, we will prepare a task order for assignment under that contract for the River Oaks neighborhood drainage study as described above.












Measurable Outcome Anticipated:






Since there are several theoretical approaches to solving the flooding problem in this area, the only way to determine the most effective method of correction is with a comprehensive basin study.  This will ensure responsible use of taxpayer money.











Amount requested from the State for this project this year:






















Total cost of the project:
















Request has been made to fund:















Type of funding match:








Total Cash Amount:















Was this project previously funded by the State?














Is future-year funding likely to be requested?













Purpose for future year funding:


YesNon-recurring Construction



Will this be an annual request?
















Was this project included in an Agency's Budget Request?




Was this project included in the Governor's Recommended Budget?













Is there a documented need for this project?






Substantial complaints from residents -- see attached map.











Was this project request heard before a publicly noticed meeting of a body of elected officials (municipal, county, or state)?




Hearing Body:

City of Fort Lauderdale Commission


Meeting Date: