On the morning of July 30, after a heavy downpour, residents of Ngora town council were shocked to find dirty black water in their basins, despite their rooftops being clean from previous rains.
Initially, many thought the black water was due to dirty roofs, but Michael Amecai, the chairperson of Kobuin cell, attributed it to an act of God.
“No one could locally interpret the unusual happening. The water could not be used for home consumption and was poured out for fear of causing harm,” Amecai said.
He noted it was the first time in his lifetime that his village received black rainwater, leaving locals surprised.
Although the black rainwater did not affect their crops, the community expressed shock at the unprecedented event.
Michael Odongo, the Ngora district chairperson, also witnessed the black rainwater.
“I wondered whether the rainwater harvested in tanks and other containers was contaminated by rotten leaves from trees near my house. It was surprising that even water from containers far from my house was black,” Odongo said.
He received similar concerns from local leaders in nearby villages, including Odwarat sub-county and Mukura town council.
Odongo advised locals not to consume the black rainwater, deeming it unfit for human consumption.
He blamed changing weather patterns on environmental degradation and urged the community to embrace tree planting to combat climate change.
A similar incident was reported in Abarilela sub-county, Amuria district.
Scientists Investigate
Officials from the Uganda National Meteorological Authority (UNMA) in Entebbe are assessing the situation to determine the cause of the black rainwater.
Retired meteorologist Aloysious Kagoro explained that water droplets are clean when they leave clouds but can pick up “dirty particles” on their way down, indicating heavy air pollution.
Kagoro mentioned a similar incident in Busia district and noted such occurrences are possible in areas with heavy bush burning.
Charles Raymond Okumu, a lecturer at Kyambogo University’s environmental science department, said rain can pick up a lot of particles, signifying pollution.
He emphasized the need for a water analysis to determine the impurities. Okumu advised residents not to use the black rainwater for consumption due to potential toxicity.
Possible Causes
Information from the US State Water Resources Control Board suggests that water colour can be affected by the presence of minerals.
Tannins, naturally occurring compounds in plants, can be released into rainwater through leaf litter or soil, reacting with iron or other metals to discolour the water.
In oxygen-rich groundwater, iron and manganese form solid mineral phases and remain undissolved. However, in oxygen-poor conditions, these elements dissolve in the water.
When this water is exposed to oxygen, it precipitates as tiny particles of iron and manganese hydroxides, causing discolouration.
Natural dissolved organic matter like tannins can also cause yellow colouration in water, leaching from leaves, roots, and other vegetation.
This colouration from iron, manganese, and dissolved organic carbon can be seasonal, with rust causing a red tint, manganese oxide causing black discolouration, and a combination resulting in a yellow-brown hue.
The mystery of the black rainwater remains, but residents are advised to stay cautious until further investigations provide clarity.
