Long, long ago, rivers were flowing free through the landscape around the world. Then the man came along and said, ‘I want water for my crops. I need to water my fields all year round, and the rains fall only during part of the year. The rest of the time, my fields are parched. A river flows past my land, and the water is wasted, flowing into the sea. Since I am a clever boy, I will build a dam and keep some of the water on my farm to have enough water for my crops all year round.’ And that is what he did.
People all over the world began constructing dams to divert rivers and harness their power more effectively. This is not only to water agricultural land but also for building hydropower stations to use water’s abundant energy to produce enough electricity for energy-sapping industries like mining. But behind these engineering blueprints lie tales of triumph and tragedy. We may feel in control of nature as we build dams to harness powerful rivers, but in reality, these structures are nothing more than houses of cards. A fragile balance contains them, and our dominance over rivers is merely an illusion, a humbling reminder of the power of nature.
A recent tragedy in Dassenberg, near Malmesbury, can illustrate this point. On August 8, 2024, the dams built along the Swart River collapsed and flooded the downstream community of Riverlands. The morning light found authorities scrambling while the residents were trying to mop up and salvage what they could after successive dam collapses caused flash floods in the area. This incident resulted in accusations of negligence and raised charges against the owners of the dams. Here’s a detailed overview of how dam construction to divert a free-flowing river poses various dangers to communities:
Risk of Catastrophic Flooding
Dam construction carries the significant risk of catastrophic flooding of the downstream areas in the event of a dam failure. While we may feel dams are essential to meet our increasing demands for water and electricity, their waters hold the power to destroy and devastate communities located downstream.
In a perfect world, those who build the dams would conduct a dam break analysis before trying to harness the power of water. However, even if those are done, they do not guarantee safety because there is no standardisation in how the dam break analysis should be conducted and reported. Many dams don’t comply with this requirement, and existing dam design standards are not based on the risk dams create but rather on the height of dam walls and storage capacities. Nobody studies what will happen when there are design deficiencies, inadequate maintenance, overtopping during unusually heavy rainfall, or the failure of spillways.
In the case of Riverlands, the Department of Land Reform and Rural Development (DLRRD) purchased the land where the dams are located and did not even enquire if those dams were licenced or complied with legislation. No stormwater management assessment was carried out, and downstream residential communities were put in danger. An investigation revealed that the dams were constructed without the necessary licenses, violating the National Water Act. Added to it was the lack of maintenance of the dams since DLRRD acquired the land in 2019.
Now, preliminary estimates of the damage to infrastructure are around R50 million, though further assessments may increase this figure. Not to mention that residents of Riverlands are currently without tap water or electricity due to damage to the plumbing and other infrastructure caused by the floods. Once again, it's the villagers who are left feeling the weight of the damage. Accusations are flying among the authorities—negligence, shortcuts, and greed are exposed. Criminal charges loom like storm clouds. All because man underestimated the power of nature.
Tragically, the story of Dassenberg is not unique. It's a global narrative that echoes across continents. From India to China and the United States, the scars of dam failures are etched in history. The toll is staggering; thousands of lives have been lost, and families have been shattered. A single dam, a moment of vulnerability, and lives are forever altered. This compels us to critically reevaluate the necessity of dam-building in free-flowing rivers.
Ageing Infrastructure Poses Dangers Of Dam Construction on Rivers
Many dams worldwide were constructed decades ago and are now reaching the end of their design lifespan (typically around 50 years) without adequate maintenance or upgrades. Ageing infrastructure increases the likelihood of failures, especially in the event of extreme weather scenarios exacerbated by climate change, such as unpredictably heavy rain falling in a short time over the dam area.
Water is a powerful force, and the Swart River dams could not contain it. They were constructed without licensing and did not meet the dam safety standards and standard engineering criteria.
Most of the world's dams were constructed after WWII until the mid-eighties, so they are reaching maturity now. They were constructed at a time when our understanding of engineering and hydropower was not as advanced as it is today. Now, these dams pose increasing danger to the public and require costly maintenance and repairs. On top of that, these weakened dams have to cope with the additional stress of climate change, which brings unpredictable and unprecedented downpours, and the additional volume of water the dams have to contain is likely to lead to dam failure.
Many of the smaller dams have also outlasted their suitability for original purpose. They no longer offer economic benefits and are isolated on private property; they provide no public service.
The rivers’ rage at being contained has already displaced millions of lives worldwide and drowned livelihoods. Victims’ existence was reshaped, homes submerged, and traditions lost. Still, we do not learn.
Increased Erosion and Sedimentation
Overall, dams harm ecosystems by changing riverine flows, leading to harmful sediment buildup within the dam and reducing holding capacity. If the dam cannot function as intended during high-water events, this could lead to increased flooding risks. The shallower dams also experience changes in water temperatures. The warmer water released into the river can cause species extinction in rivers and ocean deltas. Dams also block fish travel, threatening migratory species.
Consequential Risks
The failure of a dam can trigger a domino effect, where one failed structure leads to the failure of downstream dams, compounding the flooding risk and potentially causing widespread destruction. This means that the failure of one dam can set off a chain reaction, leading to the failure of other dams downstream, increasing the scale of the disaster, which is what happened in Riverlands.
We must improve and obey the regulations for dam building. Risk assessments must be taken seriously instead of half-heartedly. Emergency plans must be put in place and not be mere illusions. The dams stand stoic, but their guardians falter, and villagers suffer.
While dams were meant to manage water resources for electricity generation, irrigation, and flood control, they introduce significant potential hazards, particularly regarding failure risks and the consequent impact on communities and the environment. Comprehensive risk assessments are crucial to ensure the safety and protection of communities and the environment in the face of these potential hazards.
And so, we learn. The river teaches us: Listen, Strengthen the walls, mend the cracks. For when dams fail, they take more than concrete—they take lives. Better still, wherever possible, abandon dams, return the water to rivers and let them run free as they were intended by nature.
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