Chapter Five: Water Supply and Sanitation Projects

2 WATER SUPPLY AND SANITATION PROJECTS

2.1 Types of Water Supply Schemes

Effective Operation and Maintenance calls for an understanding of the types of water supply schemes. The types of water supply schemes are given below:

(a) Open wells/ Sanitary dug well/ rain water harvesting collections,

(b) Hand pumps schemes,

(c) Gravity flow piped water supply schemes,

(d) Power pump scheme,

(e) Hand pump fitted with mini power pump schemes or pump and tank scheme based on bore wells or sanitary dug wells,

(f) Single habitation and multi habitation piped water supply schemes based on surface and ground water,

(g) The sources of single village and multi habitation piped water supply schemes. These may be an open well, protected shallow wells, boreholes, infiltration wells, infiltration galleries, rivers, dams, reservoir, and canals.

The water sources that are applicable in Tanzania have been presented in Volume I. It is advised that the user of this volume should consult Volume I for more details and guidance.

2.2 Components of Water Supply Schemes

Piped water supply schemes comprise the following components, the details of which are illustrated in Figure 5.1:

(a) Source/ intake works,

(b) Raw water storages and sumps,

(c) Transmission system,

(d) Treatment plan,

(e) Pumping machinery,

(f) Disinfection plan,

(g) Balancing Reservoir,

(h) Distribution system,

(i) Water testing laboratories /storage facilities & operators quarters (depending on the size of the scheme),

(j) Clean water storage/ Reservoir.

Figure 5.1: A Typical Flow Diagram Showing a Water Supply System with Different Types of Units/Schemes to Delivery Points for O&M Surveillance Activities (Source: GoI, 2013).

2.3 Components of Sanitation Schemes

The components of sanitation schemes/services and their details have been illustrated in Volume II.