Withlacoochee River flooding: a major mark left by Irma

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Withlacoochee River flooding: a major mark left by Irma

A jeep partially submerged in the waters of the Withlacoochee River  photo by HCFR

Hurricane Irma passed over our area on Sept. 11, 2017, but its lingering effects are still being felt. There has been prolonged electricity outages, generator problems, large amounts of debris from the storm and mosquitos quickly multiplying, but perhaps one of the worst impacts is the flooding of the Withlacoochee River.

The county projected the Withlacoochee River to reach a high of 17.7 feet on Wednesday Sept. 20, threatening roughly 1900 properties. Many of these properties were without power for significant parts of last week and/or suffered damage from the storm only to be flooded by the rising waters of the Withlacoochee. The specific areas affected include Ridge Manor, Trilby, Croom, Talisman Estates, Riverdale, Nobleton and Istachatta.

Evacuation of the roughly 4,000 residents who call the area near the river home was voluntary. This was to ensure the safety of both the residents and the first responders. Local deputies, firefighters, Florida Highway Patrol as well as Fish and Wildlife Commission personnel knocked on doors to try to encourage residents to leave. Fire Chief Carroll described the scene behind Firehouse No. 8 in Ridge Manor. The first responders across multiple agencies gathered with jon boats, air boats and swamp buggies in order to plan their patrols.


Vehicles drive through streets flooded by the Withlacoochee, photos by HCFR

“It was a concerted collaborative effort… We all went out to the different areas that would be affected… and everybody did their job and made sure the people were notified by patrolling the streets in 4 - 5 feet of water or more in some areas,” said Carroll.

Community members also assembled their resources to reach out to neighbors in need. Photos of jacked up trucks ready to assist, littered social media, reminiscent of the scenes played out recently in Texas.


Ridge Manor flooding, photo by Capt. Gibson, HCFR

The Enrichment Center at 800 John Gary Grubbs Blvd in Brooksville was designated a shelter, but was quickly closed since only two individuals showed up on Sept. 17 who found alternative lodgings. It was reopened by Sept. 19 with the cresting of the Withlacoochee. The Red Cross and Hernando County Emergency Management were attempting to secure the Ridge Manor Community Center as a shelter location, but were unable to due to the community center’s prior weekend commitments.

The National Guard along with community volunteers distributed supplies to residents at the Ridge Manor Community Center on Sept. 17.

During the Sept. 19, 2017 Board of County Commissioners Meeting, EOC Director Cecilia Patella commended resident Sarah Chase who essentially ran the Ridge Manor Community Center distribution location.


Sara Chase, center surrounded by community volunteers and National Guard members at Ridge Manor Community Center.  Photo courtesy of Sara Chase

Chase who is on the Ridge Manor Property Owners Association saw the need for sandbags before the storm and called Emergency Management to see what she could do. With the impending flood, Rich Russell with Emergency Management reached out to Chase for assistance at the Ridge Manor Community Center in distributing supplies and she basically took over coordinating the efforts.


Members of the National Guard distributing supplies at Ridge Manor Comm. Center Photo courtesy of Sara Chase

“I was all too happy to do anything for my community,” stated Chase.

On Sept. 18, “due to the continual flooding… impacting the residents living near the Withlacoochee River” county leadership made the decision to extend the local state of emergency for another 7 days, which will “ensure that the emergency operations center and its partners remain in place to support the needs of the community.”

A notice of the potential flooding was first issued on Sept. 10, 2017, and was updated daily by the Emergency Operations Center. On Sunday, Sept. 17 the Withlacoochee River at Trilby was at 16.79 feet and was expected to increase to 17.5 feet by Sept. 20. By Tuesday Sept. 19, Trilby reached 17.49 feet and at that time was expected to rise to 17.7 feet. On Sept. 19 the river in the Croom area reached 10.93 feet and was forecasted to rise to 11.3 feet.

Dr. Mark Fulkerson with the Southwest Florida Water Management District provided the following information on the flood levels as of Sept. 19, 2017:

Flood Levels:

• The (crest) peak of the flood wave is entering Hernando County now.
• In Trilby, water levels are only expected to rise a few more inches and crest (peak) by tomorrow.
• In Croom, flood levels are expected to rise another ½ a foot and peak later this week.

With the flooding and associated damages, residents are being advised that their well and septic systems could become contaminated, and therefore water testing should be completed once the water recedes.
Residents are currently observing fish kills in the area.


Fish kill in the Withlacoochee, photo by Hern. Co. Gov.

Dr. Mark Fulkerson explained,

“There are currently numerous reports of fish kills in the river (adjacent to Citrus Co) because of reduced dissolved oxygen in the water right now. During high water events (i.e. Hurricane Irma) much of the river’s watershed is contributing flows to the river and those flows are coming from expansive wetland areas and sloughs that bring decaying organic matter into the river, depleting oxygen levels in the water. This is a natural occurrence during flood events.”

Dr. Fulkerson said that the Withlacoochee River in Northern Pasco and Southern Hernando County (near the towns of Lacoochee and Trilby) is naturally prone to flooding because the river becomes confined with high banks. Suddenly, the vast amount of water moving out of the wide Green Swamp is channeled into a more contained area. “This is a natural constriction where river levels fluctuate greatly,” said Dr. Fulkerson.

He described how the water will begin to recede, stating, “There is still a tremendous amount of water flowing out of the Green Swamp and once the river in Hernando County peaks, the water will likely stay up for a few days before it begins to recede. The river won’t drop as quick as it rose, but it typically drops pretty quick in Trilby once the wave of water fully passes.”

The following is a list of historic crests at Trilby.

(1) 20.38 ft on 06/21/1934

(2) 20.06 ft on 09/12/1933

(3) 19.38 ft on 03/23/1960

(4) 17.93 ft on 09/11/1950

(5) 17.25 ft on 08/05/1960

While the river has now reached historic crest levels at Trilby, during April, May, and part of June of this year the river was less than a foot high in the Trilby area. It has been on the rise since mid-June. On Sept. 11 it was at 11 feet and on Wed. Sept. 20 the river reached a crest of 17.67 feet.


Chart of River Heights at Trilby between 3/23/17 and 9/19/2017

The last occurrence of major flood stages was during the 2004 hurricane season, when Florida was hit with several hurricanes in a short time frame. Once the flooding has receded then crews can get in there to clean up and help restore the area.

Disaster assistance may be available through FEMA, Federal Emergency Management Agency, please visit www.fema.gov/

UPDATE Sept. 22, 2017: The river height at Trilby hovered between 17.66 and 17.67 feet at Trilby and then began to recede slightly dropping to 17.55 feet by Friday Sept. 22, 2017

Melissa Fordyce and Rocco Maglio contributed to this report.