New drive to curb imminent floods via rainwater harvesting
Thursday, July 09, 2020
Rwanda National Police's Fire brigade officers try to rescue people who got stuck in flooded road in Kigali on 2 Feb 2020.

Considering that only 14.5 per cent of household in the country have rainwater management systems, the Ministry of Environment has embarked on a campaign that compels all public, residential, and industrial buildings to harvest and manage rainwater in a bid to curb floods.

The move is also aimed at preserving water for use during the dry seasons.

Dr Jeanne d'Arc Mujawamariya, the Minister for Environment urged all real estate developers to embrace rainwater harvesting within two months ahead of the upcoming rainy season, which begins in September.

During this period floods usually destroy properties and human lives.

According to the ministry, inadequate methods of harvesting rainwater from buildings contributes to the flooding that also causes soil erosion.

Runoff from households as well as buildings and public roads also increase floods and destroy public infrastructure.

The ministry added that that informal settlements and urbanization increase stormwater volumes which make it difficult to collect rainwater.

Most of the buildings, especially in urban areas use to soak away pits that cause damage and destroy houses according to the ministry.

Despite having an average annual rainfall of 1200 millimetres, Rwanda is classified as a water-scarce country and therefore harvesting of rainwater would play a role in achieving water security for farming and industrial use, the Minister said in the guidelines she signed.

Minister Mujawariya said that they are having different visits to buildings which are in line with the awareness campaign to comply with the guidelines for harvesting the rainwater from buildings before the upcoming rain season starting by next September.

The new guidelines say that "every building must have adequate and safe means of harvesting rainwater and runoff from its roof and surroundings within its compound.”

In order to minimize runoff and facilitate the infiltration, buildings owners must use other permeable materials such as promoting gardens and lawns.

The recommended rainwater harvesting methods include surface tanks, underground tanks, low-cost artisanal tanks in rural areas, appropriate water ponds for small scale irrigation, water detention basins, safe infiltration basins filled with stones and gravels.

The guidelines also recommend public buildings and industrial buildings to use underground water tanks while residential buildings can use underground or surface tank with a minimum capacity of three cubic meters.

Residential houses, especially in rural areas, have been urged to use gutters to collect rainwater while real estate developments and grouped settlements have to use collective rainwater harvesting tanks.

The guidelines recommend existing unplanned settlements to install a surface water tank with minimum capacity of one cubic metre where there us space while including rainwater harvest and settlement upgrading in the plan.

The ministry said that where there is no space to install a tank, the grouped settlement rainwater harvesting approach shall be adopted.

Where there is no space in the area for harvesting the rainwater, the safe channels designated in the public detention areas have been recommended.

The ministry has recommended the transport sector to ensure all roads have adequate rainwater drainage systems.

New construction projects

The guidelines signed by Minister Mujawamariya say that new construction projects must incorporate adequate rainwater harvesting systems into their design while applying for building permits while ensuring integration of rainwater harvesting systems into urbanization programs and local settlements.

" Administrative entities must report, existing situation of the buildings without rainwater harvesting as well as newly constructed buildings without rainwater harvesting facilities.”

Augustin Kampayana, The Acting Director-General at Rwanda Housing Authority told The New Times that new construction projects that don't comply with the guidelines risk hefty fines.

He urged households to plant trees and vegetation in their compounds.

"There is a national technical team leading the inspection and those not complying, there are laws and guidelines to punish them,” he said.