1.10 Operational definitions
Water Supply Service: Providing water for domestic, commercial, industrial and social use.
Safe Water: the water protected from contamination.
Household: any unit of habitual residence where some consumption and/or production may be undertaken in common and where some members may recognize culturally defined relationships of kinship and/or affinity where the members are related in some way (asfaw 2006).
Kebele: the smallest administrative unit under city or town administration.
Potable water: water that is safe to drink.
Improved Water Supply: Provision of water in good quality or safe for health, good quantity or the required amount of water is available for use any time through out the year; and collection of water need not take much of your time and effort.
Infrastructure: is defined to denote the hard components that comprise all systems of urban physical structure that are mainly laid underground, surface and overhead to provide public services. Infrastructure in the context of this study includes the sheet network and utilities (electric, water, drainage and telephone, (UNICEF, 2006).
Coverage: refers to the proportion of people served with the adequate levels of water supply.
Urban: Built-up and populated area that includes a municipality and generally, has a population of 2000 or more
Water supply: supplying of clean water for human use.

This chapter deals with the conceptual framework, empirical framework and theoretical overview of urban water supply and distribution. It assesses the urban water supply, sources of water supply, approaches of water supply, urban water supply accessibility, challenges of urban water supply and distribution, urban water supply in developing countries in general and in Ethiopia in particular, benefits of access to safe, reliable, adequate and affordable potable water supply and impacts of inaccessibility of urban water supply and distribution facilities. In addition to these it assesses the Ethiopian government’s water supply policy, institutional arrangement and responsibilities at different levels.

2.1 Urban water supply
Alaci and Alehegn (2009) stated that, water is important in a number of ways; these include domestic and productive uses. Domestic water use takes the form of drinking, washing, cooking and sanitation, while productive water uses includes those for agriculture, beer brewing, brick making etc. Safe drinking water matched with improved water supply contributes to the overall well-being of people; it has significant bearing on infant mortality rate, longevity and productivity. However, the majority of the world’s population in both rural and urban settlements does not have access to safe drinking water.

According to WHO, (2006) cited in Mengistu, (2008), only 16% of people in Sub- Saharan Africa (SSA) had access to drinking water through a household connection (an indoor tap or a tap in the yard). Not only their poor access to readily accessible drinking water, even when water is available in these small towns there are risks of contamination due to several factors like inappropriate waste disposal and lack of water supply infrastructure such as pipe line for water.

2.1.1 Sources of water supply
According to Sijbemsa (1989), and Tesfaye and Zeyede (2004) water sources fall in to three categories. These are:
Surface water; It originates from rain water. Surface water is found non-uniformly distributed over the earth’s surface. As the rain reaches the surface of the earth, it becomes surface water or runoff. Surface water includes rivers, streams, lakes, ponds, tanks, manmade reservoirs and sea water. The quantity and quality of surface water depend upon the conditions of the surface or catchment area over which it flows. It is the main source of water supply in many areas. Surface water is prone to contamination from animal and human sources. As such it is not safe for human consumption unless subjected to sanitary protection and purification before use.

Rain water; It refers to rain is that collected from surfaces (by roof or ground catchment) and stored in a container, ponds, tank or cistern until used. This water is the purest water in nature yet
it tends to become impure as it passes through the atmosphere. It picks up suspended impurities from the atmosphere such as dust, soot and microorganisms and gases such as carbon dioxide, nitrogen and ammonia. In regions where rainfall is abundant and frequent, rainwater can be a good source of water supply for individual families and for small communities. The storage of rainwater is particularly important in areas with a long dry season.

Ground water; It may be defined as that portion of the total precipitation which has percolated downward into the porous space in the soil and rock where it remains, or from which it finds its way out to the surface. It is water used by humans comes mainly from land such as wells, springs, etc. It tends to be of higher microbiological quality having undergone natural soil filtration. However, it is relatively difficult to extract. Compared to other water sources more technology and energy is needed to bring water from within the earth up to the surface.

UN-HABITAT (2006) stated that, water service provision options are standpipes, yard and house connections.
Household connection: Household connection, is a water service pipe connected within house plumbing to one or more taps (e.g. in the kitchen and bathroom) or tap placed in the yard or plot outside the house.
Public tap or standpipe: Public tap or standpipe is a public water point from which people can collect water. Many low-income households that are unable to afford a household connection are relying on public water points.
Domestic reseller: Increasingly, households with a private connection are selling water to their neighbors.

In addition to this, UNICEF (2008) stated that, population using improved sources of drinking water are those with any of the following types of water supply: piped water (into dwelling yard or plot), public tap or standpipe, tube well or borehole, protected well, protected spring and rain water collection while unimproved sources are unprotected dug well, unprotected spring, surface water (river, dam, lake, pond, stream, canal, irrigation channel), vendor-provided water (cart with small tank or drum, tanker truck), bottled water, tanker truck provided water.

2.1.2 Urban water supply accessibility
Accessibility connotes physical availability of a service or facility. It establishes the extent to which factors like distance, time and cost have decayed. Optimum accessibility in the case of water means effectively over coming access indicators of distance, time and affordability (Alaci and Alehegn, 2009).

According to Adeyemo and Afolabi (2005), accessibility is the balance between the demand for and the supply of consumer services over a geographic space and narrowing or bridging the gap between geographic spaces is the all significance of transport. Accessibility can be seen within the context of the ease with the people can obtain the services of a facility and function. Accessibility increases with decreasing constraints both physical and social.

According to UN-HABITAT (2003) access to safe water is the share of the population with reasonable access to an adequate amount of safe water. In urban areas the water source may be a public fountain or a stand pipe not more than 200 meters away from households and the adequate amount of water which is needed to satisfy metabolic, hygienic and domestic requirements usually about 20 liters of safe water per person per day. This minimum quantity however vary depending on whether it’s an urban or rural location and whether warm or hot climate.

2.1.3 Water supply accessibility indicators
With regard to water accessibility WHO (2008) stated basic indicators of measuring water accessibility. These indicators show four paramount levels of water accessibility that include optimal access (water supply through taps continuously), intermediate access (water supplied through multiple taps continuously within less than 100m distance travel and within 5 minutes), basic access (between 100m and 1000m distance and 5-30 minutes time) and no access (more than 1000m distance travel and more than 30 minutes time). These are indicators of the level of water availability which is a measure of the quantity available for use. Basically, they reflect the extent to which accessibility challenges time, distance and affordability etc. Time and distance travel to fetch water
Time and distance traveled to fetch water are the key indicators of water accessibility. As WHO (2008) standards if households travel more than 200 meters far away from house in urban areas, there is no access. In relation to time, if the time is within 5 minutes, 5-30 minutes and more than 30 minutes, there is intermediate access, basic access and no access respectively. Affordability
The affordability of water has a significant influence on the use of water and selection of water sources. Households with the lowest levels of access to safe water supply frequently pay more for their water than households connected to a piped water system. The high cost of water may force households to use small quantities of water and alternative of poorer quality that represent a greater risk too (Public Health Protection, 2000). Private access to tap water is the cheapest for the consumer. Dependence on a shared standpipe increases prices four times. Private water