Erosion risk map of Rwanda has been developed in June 2018 using the Catchment Restoration Opportunity Mapping (CROM) Spatial Decision Support tool. CROM model was developed based the Universal Soil Loss Equation (USLE model) originally introduced by Wischimeier and Smith in 1978. The USLE model counts five input parameters derivable from Rainfall (R), Soils (K), Topography/ Relief (LS), Land cover and crop management (C), and conservation practices (P), each having a multiplier effect as follow: A=R×K×LS×C×P
Catchment planning is a form of spatial planning (integrated planning of land, water, and related resources) and is based on the principles of Integrated Water Resources Management (IWRM). The IWRM planning cycle combines the cyclical process of Catchment Plan (CP) development with a continuous learning process. Awareness of IWRM principles, knowledge about the catchment, and capacities to manage the catchment sustainably increase during each revolution of the IWRM planning cycle. In Rwanda, Catchment Plan development is integrated with the process of Strategic Environmental Assessment (SEA).
Water monitoring is done with the purpose of gathering hydrological data that show the status of our water bodies around the country, during surface water monitoring data collected are: water levels, flow rates, and sediments quantity monitoring which started this year 2019. These data are collected with the help of manual (staff gauges), automatic (divers) and telemetry stations (real-time stations i.e. those which send data as they collect them in the server room). Collecting these data is done for the purpose of quantifying the changes of the natural surface water systems hence, providing the overall status of national water bodies to stakeholders and decision-makers thus, they are helped by that information in planning for water resources.
Within the framework of meeting one of its mandates related to water quality monitoring, the Rwanda Water and Forestry Authority (RWFA) has commissioned a study aiming at establishing water quality baseline of some selected 36 water bodies in Rwanda. The study was conducted at the nine catchment level one. A set of sixteen (16) parameters were selected for this monitoring activity for each sampling site. These are: Biochemical Oxygen Demand (BOD), Dissolved Oxygen (DO), Potential in Hydrogen (pH), Electrical Conductivity (EC), Total Dissolved Solids (TDS), Total Suspended Solids (TSS), Turbidity, Chloride (Cl-), Sulfate (SO42-), Nitrate (NO3-), Total nitrogen (TN), Total Phosphorus (TP), Total Dissolved Inorganic Nitrogen (DIN), Total Dissolved Inorganic Phosphorous (DIP), Faecal coliform (F.C) and Escherishia coli (E.coli).
The overall objective of this report is to inform on : Groundwater, recharge and storage enhancement inthe Eastern Province and to identify/confirm main aquifers, understand their hydrodynamic behavior,potentiality and recharge mechanisms.
This report assesses the factors that influence the rainwater use as one of the water resources under urban water augmentation and storm water management of Rwanda.
Rwanda endeavors to manage and develop its water resources in an integrated and sustainable manner, so as to secure and provide water of adequate quantity and quality for all social and economic needs.
To enable evidence based decision making, the Rwanda Water and Forestry Authority (RWFA) generates concise, easily understood annual overviews of key parameters and locations which are indicative of the overall state of Rwanda’s water resources.
Surface water quantity
Ground water quantity
The information is based on data collected through our monitoring programme which is designed to provide stakeholders and decision-makers with information to support the sustainable development and management of our water resources, improve water productivity and to plan for the future conditions resulting from climate change.
Soil erosion is the biggest source of nonpoint pollution in watersheds worldwide, with fine sediment being the most common pollutant (eg. Gurgen 2003, Yanda & Munishi 2007, Davis & Fox 2009). In Rwanda and other areas within the Nile Basin, suspended sediments have been sharply increasing in water bodies since the 1990s (Probst & Suchet 1992, Odado & Olaga 2007, REMA 2009). The State of the Environment Report (REMA 2009) mentions that the Nyabarongo river system carries 51 kg/second of soil at Nyabarongo-Kigali, 44 kg/s at Nyabarongo-Kanzenze and 26 kg/s at AkageraRusumo. Increasing sediment loads in rivers leads to the deterioration of water quality, a condition that affects freshwater ecosystems and their capacity to deliver the critical freshwater ecosystem services upon which human populations depend in a timely and cost-effective way. For instance, sediment settles on streambeds and fill up the gaps underneath stones, thus removing habitat for aquatic macroinvertebrates (insect larvae) which feed on detritus, thus maintain water quality and constitute food for stream fishes. Sediment deposition in river channels and reservoirs also reduces volume capacity that worsens flooding during periods of high rainfall.
The work presented in this report is a proposal for a physical rehabilitation n of the Nyabarongo Upstream Watershed. This is a technical component which is part of an integrated catchment management plan but focuses more on land restoration and rehabilitation. The presented rehabilitation plan should be taken as a guiding plan that will serve as a planning tool at district level and as an IWRM awareness tool, among others, for all concerned stakeholders.
Heavy rainfall in the volcanoes area often results in floods. Whereas the observed floods may appear similar in nature, the dynamics of floods in the volcanoes area are quite different according to their locations: classic torrential rivers in the Musanze urban area and Sebeya catchment, flooded endorheic areas (catchments without external outlet) in Byangabo sector, and flooded “dry thalwegs” north east of Rubavu disctrict. A study was implemented by “Water for Growth Rwanda”. This memo provides the final results. The main studied rivers are the following ones :
Musanze-city sector: Rivers Rwebeya, Muhe and Susa
Byangabo plateau sector: Rivers Murufurwe, Mutobo, Kinoni, Bikwi, Rungu and Nyabitondore.
Sebeya Catchment: Rivers Sebeya, Karambo and Pfunda