Jefferson Parish : Drainage

The Department repairs, reinforces and stabilizes nutria damage and canal bank failures with available funding. It also performs reconstruction projects such as upgrading under-sized drainage systems and closing open ditches with pipe for efficient flow of storm water.

The Department of Drainage is also responsible for the operation, maintenance and capital improvement of 53 drainage pump stations containing 148 pumps installed throughout the Jefferson Parish drainage system. The primary goal of the Department is to provide staffing for operations and maintenance of all pumping equipment and associated machinery. All pumping equipment is driven by either electric motor drives, most of which are equipped with auxiliary power, or diesel engines. Pump station facilities are furnished with a Supervisory Control and Data Acquisition (SCADA) system to provide more efficient response and better control of operation during storm events.

The East Bank has 17 pump stations: 6 front line stations plus 11 internal lift stations containing a total of 54 pumps with a total basin outflow capacity of 19,935 Cubic Feet per Second (CFS). Additionally, a new 1200 CFS Harahan Pump Station is also being designed under SELA. With an area of 31,734 acres (2455 acres of which are drained by NOSWB Pump Station No. 6) and a population of approximately 260,000 the stations presently provide an average pumping capacity of 0.68 CFS per acre (0.68 inches of rain per hour) which will be increased to 0.72 CFS per acre (0.72 inches of rain per hour) after completion of all SELA projects.

The West Bank, exclusive of Crown Point, Lafitte and Barataria, has 18 pump stations containing a total 66 pumps with a total basin outflow capacity of 23,390 Cubic Feet per Second (CFS). With the completion of the Cousins III SELA project currently under construction, this additional 2400 CFS will bring the total capacity to 25,802 CFS. Serving an area of 48,483 acres with a population of 193,000 the stations presently provide an average pumping capacity of 0.48 CFS per acre (0.48 inches of rain per hour) which will be increased to 0.53 CFS per acre (0.53 inches of rain per hour) after completion of all SELA and State Wide Flood Control (SWFC) projects. Crown Point, Lafitte and Barataria are served by a system of multiple ring-levees and 16 remote lift stations containing 24 pumps with a total capacity of 484 CFS.

The design of pumped drainage systems starts with the return expectancy (or frequency) of various rainfall events. The degree of protection cannot be infinite, but must be related to what the public is willing to support and pay for, as very expensive pump stations, large canals with small slopes, etc. are required. Presently, Jefferson Parish designs its major drainage system to provide protection against a 10 year recurrent expectancy.

When referring to the capacity of pumps and pump stations, the term "CFS" is used. CFS stands for "Cubic Feet per Second." CFS is one of a number of ways of measuring volumetric flow, and is simply the time it takes for a measured volume to pass a fixed point. For example, a 1000 CFS pump at a pump station can move 1000 cubic feet of water every second from a canal to the other side of a levee.

In order to better appreciate the capacity of a pump station, it is best to use a measure of volumetric flow that everyone understands. Therefore, another more commonly understood term used to measure volumetric flow is GPM, or Gallons per Minute. In order to compare GPM to CFS, it is essential to know the approximately
7-½ gallons equals 1 cubic foot. Since there are 60 seconds in a minute, 1 CFS equals approximately 7-½ gallons times 60 or almost 450 GPM. This would mean that a 1000 CFS pump moves approximately 450,000 gallons of water every minute! With the entire post SELA & SWFC capacity of Jefferson's pump stations being 47,100 CFS, which translates into over 21 million gallons of water pumped every minute!

The organization of the department is comprised of administrative, operations and maintenance divisions. Some of the major pump stations are furnished with an operator's resident house; other major stations are manned with either two or three eight (8) hour shifts, depending on their locations.

On weekends and holidays, as well as during non-manned periods, pump station operators are placed on stand-by and remain ready to activate the stations at a moment's notice should the need arise. However, if rain is forecast the stations will be manned.

Remote lift stations operate automatically and are inspected daily by the operations division.

Jefferson Parish has designed and constructed Safe Rooms at thirteen (13) of the Drainage pump stations. Pump station operators and screen cleaning personnel will occupy these Safe Rooms during the passage of a hurricane. The Safe Rooms are designed to withstand 250 mph wind load and water surge produced by a Category 5 hurricane. These Safe Rooms are equipped with remote control capabilities to operate all of the pumps at the (13) pump stations which include the original eight (8) safe rooms with capacity of remote operation of horizontal pumps.

Parish Line Pump Station will be remotely operated from Duncan Pump Station Safe Room and Westminster Pump Station will be remotely operated from Ames Pump Station Safe Room.

The existing air suppression system has been enhanced to more efficiently utilize the compressed air system to combat any possible backflow from the Lake through the horizontal pumps until such time that Corps of Engineers completes the Fronting Protection project in 2011.

The Parish is currently in the process of developing a Parish-wide Subsurface Drainage Master Plan. The purpose of this Plan is to help identify deficient drainage areas throughout the Parish, develop preliminary solutions for the problem areas, split problem areas into individual projects for bidding purposes, develop cost estimates, and prioritize needed work.

Call the Drainage Central complaints Division at 736-6578 (East Bank), 437-4939 (West Bank) or 736-6006 (Weekends & After Hours). Email: PFirmin@JeffParish.net

Frequently Asked Questions

Are the pumps turned on?
At the major pump stations, the operators start the pumps when the water level rises to a set elevation, whereas, at the smaller stations the pumps start automatically. Supervisory Control and Data Acquisition (SCADA) equipment is set to monitor water levels and pump operations. At any given time, the SCADA screen indicates the operational status of all pumps at the stations. Westwego No. 2 in the West Bank and Duncan Pumping Stations in the East Bank are equipped with a SCADA monitoring system. SCADA operators monitor the rain events and canal water levels at all drainage basins Parishwide around the clock and notify the superintendents on stand-by to take immediate action to resume operation of the pumps in case of any rain event or rising canal water levels.

How much rain has fallen?
Amount and intensity of rainfall is also monitored by the SCADA system. The SCADA screen indicates incremental and total rainfall at any given time.

Why doesn't water appear to be moving in the canals?
As the rate of storm water inflow exceeds outflow in any reach of the canal network, the water rises, occupies more storage and creates the illusion of no flow.

Why aren't the pumps on and running before a rainfall event?
The pumps cannot be turned on unless an adequate depth of water exists at the inlet basin of the pump station otherwise pumps could be damaged.

Why can't we hear the pumps running?
Many of the pumps are electric motor driven and run very quietly. Engine driven pumps are housed inside operating buildings and can only be heard near the stations.

Why is the street flooding & water not draining off the street?
Many existing drain lines especially in the old areas prior to 1981 were not designed to handle a high rate of rainfall in a short time. As a result streets will flood when a high intensity rainstorm of short duration occurs. Many existing drain lines were designed and built to old standards which equates to smaller pipes. Sometimes drains become clogged with leaves and debris, reducing their ability to carry the storm run-off.

When are they going to cut the grass on the canals and ditches?
In Jefferson, there are approximately 700 miles of canals banks and ditches requiring grass cutting. Grass cutting on canal slopes is cut, on an average, six (6) to eight (8) times per year and canal flats are cut up to eighteen (18) times per year, weather permitting.

Why is my sidewalk or driveway sinking?
There can be several reasons for this:

- Natural subsidence and settlement;

- Tree roots causing cracking and settlement of sidewalks and driveways;

- Leaks in drain lines, sewer lines, water lines, etc.