As many of us have seen with our eyes yet again the awesome power of nature, it is a sad reminder of how vulnerable we are. We will recover no doubt, but all the factors both natural and man-made that are a menace to our tranquil existence will remain close at hand. We must continue to look squarely at hard decisions that must be made to at least lessen the impact from such events, particularly in light of a changing climate.
For my whole professional career as a forester in the forestry department here in St Lucia and now…at the regional CARICOM level, the call has always been to give careful consideration to how the lands (and water resources) are managed. The most critical areas that deserve attention are our rivers; for generations upon generations we have carved away the trees from the riverbanks, farmed and built homes and businesses on the rivers’ edges. The result is that when it rains, the banks erode as the rivers run full, and the silt is moved along the river channel; some makes its way to the sea where it blankets, smothers and degrades the offshore reefs, while the heavier stuff gets left back and stays in the river channel, raising the level of the river bed, and further increasing its flood potential! (Then the Ministry of Works goes in and de-silts – with irresponsible excavator operators destroying some of the remaining trees in the very same process!)
The problem we have faced is that as the population has grown, urban development has expanded into unsafe areas…really unsafe areas…including river floodplains and steep, mountainous hillsides. With this development, the local environments are pushed beyond the safe carrying capacity, and at a given trigger point will fail with disastrous results.
In view of all this, we have advocated to our professional colleagues in the planning ministries (St Lucia and other countries) for the establishment of protective buffer zones along the lengths of major rivers. In St Lucia from way back to the 1940s when the colonial government was selling off land adjacent to rivers (or granting private title by way of Crown Grants), a buffer zone was always shown on survey plans…steep areas were also were marked as ridge reserves…local surveyors can attest to this fact. (By the way, the 1966 Soils Survey of St Lucia included land and water conservation recommendations…all of which remain valid to this day).
As far as I know, these buffers have all but disappeared from consideration in modern day land transactions. So the problem is that many tracts of land adjacent to rivers are privately owned and the majority of land owners, in spite of better advice, choose to cultivate, build and pave over what remain as biological/hydrologic corridors, rather than allowing them to function as they should, to ‘dampen’ flood flows and stabilize soils from being eaten away from the riverbanks by raging waters.
An important note here however: Having such buffer zones will not prevent flooding. Flooding in river systems is natural once the rainfall accumulation is enough, and can never be stopped by human engineering, although we can lessen the impact through designed/engineered solutions. I must also mention that in many areas (not all) where WASCO has abstraction intakes, the lands upriver are degraded. For instance, the Talvan River, a tributary of the main Marquis River, flows through housing development areas and farmlands with so much exposed soil, that when it rains the river flows as a brown slurry in no time, forcing the operators at the Hill 20 Plant at Babonneau to contend with treating this highly turbid (muddy) water or simply shutting off the supply altogether. Turbid waters increase the cost of water treatment tremendously in terms of chemical inputs and man-power; intakes which silt up in heavy rain need to be un-choked by hand and shovel.
Extreme climate events are like the foot on the accelerator, so it seems to me that a few things MUST be pursued as a matter of policy and execution by government, and embedded within the climate change response strategy:
1. Consider more strict development controls within floodplains and steep landscapes…perhaps a moratorium in particularly high risk areas for certain types of development
2. Seek out measures which encourage landowners to maintain major watercourses under protective forest: reforest riverbanks and declare them by statute as protected – there are provisions (to allow this) in the Water and Sewerage Act.
3. Install a mix of engineered and bioengineered solutions along riverbanks, particularly along communities that run adjacent to rivers (maybe include levée-type walls, although that comes with its own risk should there be overtopping).
4. Consider design for longer-return events…we cannot rebuild with the same configurations only to see them fail, although the realities of cost may dictate otherwise. A lot of these initiatives are now being termed climate-smart.
All of what I have said here has been contained in watershed management reports written by me and my contemporaries, professionals before me, authors of reports post-Tropical Storm Debbie (1994), post-Hurricane Tomas (2010) and the list goes on.
None of this is news.
I often say that we know most of what we need to know to take decisive action…No need for more studies to say the same although we do need to continue to collect necessary data. In closing, I urge a national re-focus on our land and water resources management policies by the highest levels of government NOW!!!
Christopher Cox PhD
Programme Manager/Technical Coordinator
Environmental Health / Environmental Management Unit (formerly CEHI)
Caribbean Public Health Agency (CARPHA)