Water
Rwanda endeavors to manage and provide water in adequate quantity and quality for all social and economic needs. Wastewater from industrial activities continues to be a major source of water pollution in Rwanda. In this respect, various measures have been put in place to ensure high water quality.
Water basins
Congo and Nile basins
Pollution major source
Industrial wastewater
Alarming Parameters
Dissolved Oxygen, E-coli, turbidity
Pollution impact on health
2,306 death in 2016
Overall, the latest nationwide water quality monitoring study indicates that for all 36 waters (30 open water bodies, rivers and lakes; and six groundwater bodies) monitored in 2018/19, the proportion of water bodies with good ambient water quality reached an index of 85 percent. However, considering the five core parameters (dissolved oxygen, electrical conductivity, dissolved inorganic nitrates, dissolved inorganic phosphate, and pH), in addition to turbidity, TSS and E.coli, which are alarming for the case of Rwanda, the percentage of water bodies with ambient water quality only reaches 18.75 percent.
This is due to the fact that certain water quality parameters such as dissolved inorganic nitrogen, dissolved inorganic phosphorus, electrical conductivity, hydrogen potential (pH), are generally within the acceptable range nationwide while dissolved oxygen (DO), Escherichia coli (E. coli), and turbidity are almost always outside the acceptable range for natural potable water. The main cause is sedimentation and siltation of water bodies mainly from soil erosion and microbiological contamination linked to poor sanitation systems and practices.
Rwanda has made progress in improving water quality and access to water and sanitation in rural and urban areas. The following are some examples of government interventions and plans to improve water quality
Description and Facts
Both natural processes and human activities, including the methane exploitation, lead to changes in Lake Kivu. Such changes could potentially increase the risk of a gas eruption, they could deteriorate the water quality and lake ecological integrity, or they could negatively affect the methane exploitation. The lake monitoring aims at detecting such changes as early as possible before they develop into larger problems. The lake management and methane exploitation strategy can then be adapted to either avert a negative development, or at least to reduce its negative
impacts.
Created in 2008 with the operationalization of KPI (Kibuye Power One) pilot plant, Lake Kivu Monitoring Programme (LKMP) was a special entity within “Energy Development Corporation Limited” of the Rwanda Energy Group (REG). In 2021 Lake Kivu monitoring activities were transferred in Rwanda Environment Management Authority (REMA) after the government decision under the Official Gazette n° 32 bis of 19/10/2020 that compose the Division of Environment Analytics and Lake Kivu Monitoring. LKMP has been mandated to monitor the impact of methane gas extraction on the Lake by protecting the Lake’s stability, its environment and by ensuring that the socio-economic benefit to the population is maximized. The concession for Methane Gas extraction today has been granted to different companies mainly for electricity production and other uses. Companies are Kivuwatt, Shema Power Lake Kivu Ltd, Gasmeth, Magma Energies Ltd. Currently, only Kivuwatt is operational with 26 MW electricity production since 2015 other operators are expected to start soon.
For that, Lake Kivu monitoring activity under REMA ensures that methane gas operators comply with the Managements Prescriptions for Development of Lake Kivu Gas Resources (MPs), which is a set of prescriptions developed by a group of international experts on Lake Kivu for the sustainable and environmentally friendly Methane gas extraction.
Environment analytics and Lake Kivu monitoring (EA&LKM) division collaborate on regular basis with international, region and local research institutions to promote research on Lake Kivu by developing a strong and effective research network on Lake Kivu.
Objectives of Lake monitoring
Lake Kivu is an ancient rift lake. Around 12 000 years B.P., lavas flow from the Virunga volcanoes dammed its former outflow to the Nile. By 9 500 years B.P., Lake Kivu had become a deep lake with an overflow via the Ruzizi River to Lake Tanganyika. The lake became strongly stratified about 5 000 years B.P. when volcanism and hydrothermal activities began.
Only 31 fishes species live in Lake Kivu. The Tanganika sardine (Isambaza) was introduced in the 1960s, to fill the empty pelagic zone. The Isambaza sustain traditional fisheries and is an important source of protein for the local population. The food web of Lake Kivu is simple: phytoplankton are eaten by zooplankton, which are fed by Isambaza fish.
Catchment area: 5097 km 2 (excluding the Lake), relatively small compared to the Lake surface.
5 Basins around Idjwi Island: Main Basin, Kalehe Basin, Ishungu Basin, Bukavu Bay and Kabuno Bay.
Rivers: ~200 small inflowing rivers, but no surface water in the volcanic region of Goma Internal sub-aquatic springs: in the north, at different depths mainly at 180 and 250 m. Annual Lake level fluctuations: 0.17 to 1.17 m
The water column is characterized by increasing temperature, salinity, and gas concentrations with depth and by several sharp gradients resulting from subaquatic springs. The annual deep mixing occurs during the dry season (June to September). The mixing depth varies annually but is limited to a maximum depth of 70 m. Below this oxygenated zone, the different layers are homogenous and stable. Lake Kivu is therefore permanently stratified.
Carbon dioxide: ~300 km 3 STP, 80% of the gases volume, only 20% of the total gas pressure. Methane: ~60 km 3 STP, 20% of the gases volume, but 80% of the total gas pressure.
These gases are dissolved and trapped below 260 m depth, where they accumulated over ~800 years. This unusual accumulation can be explained by the lake’s permanent stratification and the input of carbon dioxide from the surrounding volcanoes. CO 2 has a magmatic origin. CH 4 is generated biologically by the reduction of magmatic CO 2 (~65%) and the mineralization of organic carbon (~35%).