The Water Sources Authority (WRA) is reporting that the flooding affecting sections of Content material in Williamsfield in Manchester is because of a major rise in groundwater ranges within the native aquifer system.
Groundwater measurements from the Content material borehole point out that between September 25 and November 3, Jamaica’s groundwater ranges elevated by about 100 metres (330 ft).
The rise occurred because the nation obtained heavy rainfall earlier than and through the passage of Hurricane Melissa.
Managing Director of the WRA, Peter Clarke, informed JIS Information that the incidence just isn’t unfamiliar for the world, with the final notable incidence being in 2002 after a interval of heavy rainfall.
He defined that whereas some rainwater runs off by itself by way of totally different channels, most of it’s absorbed into the bottom to make up the nation’s groundwater reserves.
“If it turns into a case the place the water that’s soaking into the bottom is greater than the speed of move that the groundwater can accommodate then, as an alternative of flowing away, it rises. Groundwater doesn’t move as quick as river water so, whenever you see it raining and the river is a raging torrent because it goes downstream, your groundwater strikes an entire lot slower than that,” Mr. Clarke identified.
The info present that the floor flooding comes from the energetic upward motion of water by way of a close-by sinkhole.
“Image that the entire Content material space is a really giant bowl, and the water has been coming underground and from the aspect after which it breaks by way of the aspect of the bowl, mainly. On this case, now we have decided that it’s rising by way of sinkholes that may usually take water away, however it’s now utilizing the sinkhole as a conduit to stand up,” added Mr. Clarke.
The WRA has put in a flood gauge within the space and has begun routine monitoring of water ranges.
Present observations present that the floodwaters are rising at an estimated price of 0.014 metres (0.046 ft) per hour, primarily based on measurements taken on November 3.
“[This] interprets to only underneath a foot [of water] per day. So, it’s presently rising. How excessive it is going to rise will rely upon, as an illustration, if we get extra rain later within the week and the way lengthy it is going to keep will rely upon how briskly it could possibly finally move away,” Mr. Clarke informed JIS Information.
The WRA will proceed to watch the state of affairs carefully and supply updates as circumstances change. Nonetheless, the rise is predicted to proceed till groundwater ranges stabilise.
“That is only a pure phenomenon. The physicality of the hydrology that’s there’s not something that you may or would need to do something to attempt to cease,” Mr. Clarke identified.
Assessments have additionally begun within the Consolation Corridor/Evergreen areas of Manchester, the place groundwater has traditionally risen and precipitated property flooding.
