Three facts beneath the surface of Big Pond’s recurrent flooding

There have been several talks of finding a permanent solution to the age-old conundrum but answers remain elusive.

Recent talks of an estimated US$8 million World Bank loan earmarked for rehabilitating Big Pond should ease the pain of thousands of frustrated residents who commute through the flood prone area on a daily basis.

So what are the real issues here?

According to National Works Agency (NWA) senior engineer Howard Prendergast Big Pond is a natural catchment.

During the rainy season or whenever it rains for any prolonged period the pond’s flood waters often rise as high as two and a half meters, leaving many in its immediate surroundings marooned, while forcing motorists to use the longer alternate route through Browns Hall resulting in increased travel time and vehicle operating costs.

What lie beneath the surface of Big Pond’s recurrent flooding are these important facts, based on the finding of several NWA studies conducted in the area.

In its 2017 Roadster newsletter, the NWA identified three major facts highlighted below.

One: The catchment has gradually become unable to hold the increasing volume of storm water that flows naturally to it from some 2,050 acres of surrounding land after a bout of heavy showers such as the five-day flood event in May 2017.

Two: This is due, in part, to the obstruction of a naturally occurring earthen drain which empties the catchment since unwittingly the waterway has been dumped to facilitate the expansion of the housing stock as well as to create new access roads to these developments.

Three: The problem is compounded by the reduction in the effectiveness of another of the pond’s natural drainage features, sinkholes. Their efficiency in emptying the pond has been reduced by prolonged silting and heavy debris build-up.

Back then the proposal is that under the Big Pond Drainage Improvement Project the pond area will be dredged as much as two meters deep in some sections to increase its holding capacity.

“A section of the roadway, one kilometer-long, which is now susceptible to flooding, will be raised 1.8 meters at the highest point so that rising pond waters can be channeled into a concrete/HDPE overflow pipe, 1.1km long, before reaching the roadway.

“The overflow will then be transferred into Myton Gully, a connecting earthen drain. The pond’s sinkholes will also be rehabilitated and the Myton Gully itself will be upgraded with pavement in some sections. The flood mitigation works at Big Pond will be enhanced by the widening of two box culverts at Church Pen, along Old Harbour Road, a project which will be executed under a separate contract,” the NWA wrote then.

A large portion of this plan we believe will be implemented, save and except for a few minor adjustments here and there. In fact now we understand why both Church Pen bridges underwent major infrastructural work at the same time as some of the water from Big Pond will channel into these two earthen drains.

With the works at Church Pen basically complete now the NWA said: “It makes good engineering sense too that the drainage improvement work downstream be undertaken simultaneously or even before works on the pond itself begin.

As Howard Prendergast explains “the NWA does not intend to release a large volume of water downstream before improving the capacity of the infrastructure to handle the increased flow”.

So after decades of devastation and inconvenience, the long wait for the permanent solution to Big Pond’s recurrent flood issues seems nearing its end.

For those impacted the most, the work cannot start soon enough.