Gatundu South is an electoral constituency in Kiambu County, Kenya and the seat of the subcounty Officer is in Gatundu Town. It is one of twelve constituencies in Kiambu County which comprises four wards: Kiamwangi, Kiganjo, Ndarugo, and Ng'enda. All of them are within the Kiambu County Council. The constituency was established before the 1997 General Elections. Previously it was part of the larger Gatundu Constituency which was split into Gatundu South Constituency and Gatundu North Constituency. It is ranked 182 out of 210 Constituencies in Kenya in size and 165 out of 210 in population size.
The current Member of Parliament is Gabriel Kagombe who succeeded Moses Kuria in 2022.
Theta Dam
Theta Dam is in Gatundu South. It's located inside Kinale Forest, its being constructed across Theta River in Gatundu South constituency. The project includes construction of a 17-meter-high compacted earth fill dam, Construction of a reinforced concrete spillway and Laying of a 3.5 km long 500mm diameter steel pipeline up to the Mundoro forest edge.
On completion, Theta dam reservoir will have a storage capacity of 2 million cubic meters (2 Billion liters). This will enable production of 15,000 m3/day of water that will augment both the Ndarugu and Thiririka water projects reliability. This will improve water supply to the upper parts of Gatundu such as Gachika, Kiamuoria, Kiganjo, Gatitu of greater Kiganjo location and upper parts of greater Ndarugu locations.