NEW ORLEANS — Sewerage & Water Board of New Orleans (SWBNO) is providing the following update regarding the significant rainstorm that occurred on July 11.

There were no power issues from the static frequency changers at the Power Complex during the event. Additionally, there is nothing mechanically wrong with the pumps at Drainage Pump Station 7 (DPS 7). Water levels at that station rose six feet in 20 minutes as a result of the intensity of the storm.

Rainfall Totals

The Carrollton, Hollygrove, and Uptown areas received more than 3.5 inches of rain in one hour. Mid City received between 2 and 3 inches in one hour. Instantaneous rainfall intensities of 6.5 to 7.5 inches per hour were recorded at points during the storm.

District A Impacts

The majority of flooding impacts occurred in District A due to a combination of intense, short-duration rainfall and pump issues at two stations, DPS 7 and the Pritchard Pump Station.

At DPS 7, human error was a contributing factor in the delayed activation of pumps. The station has three pumps. The first pump began operating as expected. While bringing the remaining two pumps online, a vacuum system issue arose that resulted in a delay of 45 minutes to bring the pumps back online. This contributed to elevated water levels affecting the lower Lakeview and Mid City/City Park areas for approximately 1.5 hours.

SWBNO is adding staff at DPS 7 in the short term to ensure correct pump station operation. An internal investigation is underway, and training protocols will be reviewed and enhanced as needed.

The Pritchard Pump Station in Hollygrove is an automatic, unmanned facility with two pumps. The pumps are checked three times weekly, with additional checks performed ahead of anticipated rainfall. On July 11, both pumps activated automatically at approximately 1:15 p.m. One pump went offline at 1:30 p.m. and required manual restart. This contributed to elevated water levels affecting the Hollygrove neighborhood for approximately two hours.

SWBNO is increasing monitoring at the Pritchard station and evaluating notification systems to alert staff when automatic pumps go offline.

Uptown and Claiborne Avenue

SWBNO's drainage system is designed to accommodate one inch of rainfall in the first hour and one half inch per hour thereafter. Rainfall on July 11 exceeded this capacity in many areas, overwhelming the surface drainage system. Even when catch basins are clear of debris, draining a large volume of water requires time.

Underpass Closures

The Carrollton Underpass was closed during the event. The pump at this location remained functional and operating throughout. However, elevated water levels in the Palmetto Canal make it difficult to pump additional water into the canal.

The Marconi/City Park and Canal/I-610 underpasses also experienced flooding during the event and have since returned to normal conditions. The Canal/I-610 underpass is located within the DPS 7 drainage area, and the pump issues at that station were a contributing factor to flooding at this location. This underpass also experiences flooding when canal levels are elevated.

The Marconi/City Park underpass pump operated as designed throughout the event. Debris in nearby catch basins temporarily slowed drainage at this location. Crews removed the debris to restore normal drainage.

Understanding Canal Levels

SWBNO also wants to clarify how the drainage system operates. Above ground canals and underground box canals convey stormwater to pump stations, which then discharge the water into Lake Pontchartrain. High canal levels do not indicate that water is failing to drain. In most cases, elevated canal levels indicate that pump stations are actively pumping water as designed.

Media Contact:
SWBNO MEDIA
media@swbno.org