Figure 4.45 High tides cause floods in residential areas in Lamu

4.4.3 Climate resilient infrastructure projects

A series of climate resilient infrastructure projects are proposed to support the sector development in a resilient and sustainable way.

4.4.3.1  Project 12: Lamu Old Town drainage, wastewater conveyance and disposal

Lamu Town has a network of open drains and buried culverts along the town’s paved streets draining into the Indian Ocean. The open drainage system was created to collect rainwater from roof gutters and drain it to the ocean and was not adequately designed to cope with the increased surface water runoff during storm events seen today131. Furthermore, as Lamu Town has grown, the number of piped water connections, pit latrines and shallow septic tanks have equally grown. Due to the lack of a separate sewerage system, grey water from homes has been connected to the open drains; and misconnections, that are a result of the lack of a sewerage system, reduce the open channels’ capacity to drain surface water effectively.

Black water discharge to the open drains is another major issue that not only adds pressure on the open drains and causes a foul smell in the town but also poses a serious health risk to residents and street users and can cause harm to marine life. High rates of waterborne diseases such as typhoid and dysentery are common132. This has mainly been found in poorer areas in the upper city and the lower quarters of the suburbs, where septic tanks are not affordable, and space is not available133. Stagnant water in the drains also acts as a breeding ground for disease-causing parasites such as malaria-carrying mosquitoes. During rainy season, water puddles form on roads, streets and footpaths, despite the gradient sloping towards the ocean134, see Figure 4.45. To compound the issue, poor solid waste management means open drains often become blocked with solid waste and silt. This further reduces their capacity. Furthermore, solid waste often forms further obstacles along the roads that leads water mixed with donkey dung, this water remains stagnant for days posing further health risks.

Figure 4.45 Rainwater flowing in the streets during a rain shower (below and right) and roof downpipes and sewer pipe draining to the open channel (last image)

Source: Atkins site visit Furthermore, storm surges often cause flooding along the sea front road as ocean water overtops the quay wall and encroaches onto the road and into Lamu Town. This further exacerbates the local drainage network as water from the streets and open drains mixes with the ocean water and cannot drain out to the ocean until waters recede.

131 UNESCO, Final Mission Report, Water and Sanitation Assessment Mission to Lamu (2005). 132 Coast Water Services Board, Final Master Plan Report – LAMU Island (2012). 133 UNESCO, Final Mission Report, Water and Sanitation Assessment Mission to Lamu (2005). 134 UNESCO, Final Mission Report, Water and Sanitation Assessment Mission to Lamu (2005).