Regional Office Based in Machakos
Total area of ACA is 58,639 Km2, corresponding to 10.2% of the country’s total area.
The drainage area of the Athi River is 37,750 km2 . The Athi River flows from the southeast of Nairobi; north-eastward in the upstream reaches, and then turns its flow direction to the southeast in the north of OlDoinyoSapuk National Park, and flows along the catchment area boundary with the Tana Catchment Area, and pours into the Indian Ocean in the northern of Malindi. The Lumi River, Lake Jipe, and Lake Chala flow into the territory of Tanzania and the Umba River reversely flows from Tanzania to Kenya. Other rivers such as the Rare, Kombeni, Mwache, Pemba, and Ramisi rivers flow into the Indian Ocean and the total drainage area totals 19,493 km2. Territorial waters within Athi Catchment Area include Indian Ocean, covering a shoreline of approximately 210 km and extending into the sea 22Km or 12 nautical miles. There are several major springs in ACA such as Mzima, Kikuyu, NjoroKubwa, Nolturesh and Marere.
Administratively, the drainage basin covers: Nairobi, Makueni, Taita Taveta, Kwale and Mombasa Counties, part of Kiambu, Machakos, Kajiado, Kilifi, Kitui and Nyandarua Counties. Major cities and towns found in ACA are Nairobi (the Capital City), Mombasa (the second largest), Kiambu, Kajiado, Machakos, Malindi, and Kilifi. Other upcoming cities include Konza, Machakos, Tatu, and Diani Resort
Available Water Resources
The available water resources consisting of the surface water runoff and sustainable yield of groundwater were estimated in ACA for the years 2010 and 2030 as follows:
Annual Available Water Resources
|Year||Available water resources (MCM/year)|
|Percentage of 2010 values||111%||98%||109%|
Source: NWMP, 2030
The total storage volume of the existing water resources structures/facilities in ACA is approximately 22MCM, which is equivalent to the sum of the dams and small dams/water pans.
Water Demands by Subsector
As per the NWMP 2030, the annual water demands estimated for the year 2010 and projected for 2030 in ACA for the various sub-sectors, estimated the population density of ACA to be 167 persons/km2 (Census, 2009).
|Year||Water Demands (MCM/year)|
Source: NWMP, 2030