National Water Conservation and Pipeline Corporation commissioned CAS Consultants Limited to undertake the EIA study for the proposed Isiolo Dam Project near Oldonyiro at crocodile jaws (Nkutuk Elkinyang) along Ewaso Nyiro River. As part of the EIA study process in Kenya, CAS Consultants has prepared EIA Report (the report) for submission to NEMA as a fulfillment of EIA Regulations 2003 and EMCA 1999. As herders who live downstream, we have christened this dam as “The dam of the death”.
The Environmental Impact Assessment findings presented in this EIA Report provides a critical examination of issues considered important in fulfilling the requirements of a clean, sustainable and healthy environment especially in a project that would touch on various phases of the environment; biophysical and socio-economic setting.
Every dam causes partly temporary and partly permanent submergence of land in the upstream and displacement of economic interests on land and their property generally, along with submergence of plant life and disruption to animal life.
Also downstream of dams, such effects are caused by ancillary facilities on a similar but much smaller scale. The consequent social and economic loss is generally assessed and compared with benefits due to the dam.
The downstream uses are met with mostly from flow by gravity or regulated releases into the river, whereas in the upstream, lifting of water is involved. All these disadvantages have to be assessed in advance to plan ameliorative measures. During implementation of the project and during operation, each disadvantage calls for careful management and monitoring.
The Proposed Project
The proposed Isiolo dam has a maximum height of 83m with the crest on 1580masl while the bed level is on 1497mas. The storage capacity of the reservoir is approximately 215 MCM of water and the water will flow by gravity to the Isiolo Resort City and Isiolo Town alongside other rural areas targeted for supply.
In addition to storing flood flow from the Ewaso Nyiro river for regulating downstream flows during dry periods, The zone to be inundated by water upon completion of the dam is expected to extend about 1500 Ha in area and a further acquisition of 500 Ha for exclusive conservation use and dam buffer totalling 2083Ha.
At the time of the study, the river was generally flowing and the dam site had weir serving local community and oldonyiro centre. There were hippos, elephants and impalas grazing on the riparian among other wild life.
The proposed dam area is characterized with sparse vegetation comprising of indigenous trees mainly Acacia mellifera, Acacia seyal, Acacia nilotica, Acacia senegal and Acacia tortillis with under growths of shrubs and grasses including Cyperus esculentus, Cynadon. Nlemfuensis, Eragrostis tenuifolia,Eleusine indica, Digitalia Spp and Dactylectium Spp on the dry land while reeds (phragmites) and cyperus species and aquatic grasses are found on the river banks. Below is a summary of the project design components.
Potential Positive Impacts
The positive impacts associated with the proposed project include:
- The dam will be effectively used to regulate Ewaso Nyiro River and enhance flows of the dam by storing the flood volume and releasing it later ensuring a sustainable supply of water to various users downstream and subsequent flooding of Lorian swamp all year round.
- Improved land use systems occasioned by availability of water in the area. The project will attract more investment to the region hence leading to accelerated business growth.
- The project will ease the current water deficit in Laikipia, Samburu and Isiolo counties and the environs consequently promoting the country’s economic growth.
- The proposed project presents an opportunity for tourism, training and skills acquisition.
- The goods will be sourced from local suppliers thus creating a ready market leading to general economic growth.
- Provision of employment opportunities during both construction and operation phases of the project. Impoundment itself may however be favourable to some fish species.
- Improved infrastructural services within the project area opening it up for development opportunities.
- Improved livelihoods in the three counties due to improved access to clean water and socio-economic benefits both directly and indirectly.
- Reduction of human wildlife conflicts occasioned by scarce water resources.
Potential Negative Impacts Associated with the Proposed Project.
The negative impacts identified which need to be mitigated appropriately include:
- Loss of vegetation;
- Loss of wildlife habitat 2083 Ha;
- Effects on farming and traditional land uses;
- Soil erosion;
- Air, dust and noise Pollution;
- Sanitary and health problems from construction camps;
- Land degradation due to material harvesting;
- Landscape changes;
- Changes in the downstream water quality;
- Reduction of biodiversity due to blocking of movement of organisms;
- Spread of waterborne diseases; spread of malaria, bilharzia and river blindness may proliferate from stagnation of the watercourse;
- Exclusion of future land uses;
- Turbidity and siltation during filling;
- Danger of people drowning either intentionally or accidentally looms with the construction of this dam;
- Break up of community bonds;
- Loss of livelihoods;
- Proliferation of squatters and vagrants within towns neighbouring the project area;
- Increase in incidences of anti-social behaviours;
Attached is the comprehensive report as prepared by National Water Conservation and Pipeline Conservation in conjunction with CAS Consultants for your perusal: