A Crucial Need for Rainwater Harvesting in Rural Schools in Ethiopia

Transcription

1 A Crucial Need for Rainwater Harvesting in Rural Schools in Ethiopia Paper Presented at the 14 th IRCSA Conference, August 3 6, 2009 Kuala Lumpur, Malaysia, By Girma H. Gode, Ethiopian Rainwater Harvesting Association (ERHA)

2 Ethiopia: Some Related Information Population 74 mln (2007 HP Census) 84% rural and 16% urban 50.4% male and 49.6% female Pop. growth rate ( ): 2.59% (UN/DSEA, 2006) Fertility rate (birth/woman): 5.1 (CIA, 2007) Area 1.13 mln km 2, with up to 65% arid, semiarid and dry lands (ASADL);

3 Ethiopia: Info (Cont d) Subsistence agriculture predominates the economy accounts for 46% GDP; and generates 85 % employment Water resources: Divided into 12 drainage basins (8 river basins, 1 Rift Valley lakes basin, and 3 dry basins with no or little discharge) The 8 river basins are estimated to generate over 12 bln m 3 of surface water (runoff) per year This implies a per-capita fresh water share of 1,700 m 3 /year amongst the population

4 Ethiopia: Info (Cont d) However: The above is yet untapped potential resource The levels of water accessibility and quality for the basic needs (domestic use and production purposes) of the peoples is very low; According to the GoE-EU joint Final Sector Review report of 2006, the national average coverage/access to clean safe water supply was 42% (with urban 80% and rural 44%) (taking a locally adjusted/shrunk access measure/definition of average water consumption of 15 l/c/d within 1.5 km radius for rural areas, which is commonly taken as 25 l/c/d within 1.0 km; and of 20 l/c/d within 0.5 km radius for urban areas, which is commonly taken in the order of 35 l/c/d within 0.1 km) This water supply coverage is considerably lower than that of the African continent, which was 62% in 2002,

5 Ethiopia: Info (Cont d) Why is water so a scarce commodity in Ethiopia? The key reasons/factors among many others: Extreme variability or unevenness in the spatial and temporal distribution and amount of rainfalls and of the water sources themselves Low investment and technological capacity to divert fresh waters from where they are situated to places where they are needed most Dwindling or shrinkage of some of the water sources due to the effects of: global phenomena (climate change, desertification, etc), and other local anthropogenic/demographic factors, notably rapid population growth and the resulting pressure on finite natural resources (land, soil, vegetation, and water)

6 River Basins of Ethiopia Mereb B. Denakil B. Tekezie B. Awash B. Abbay/Blue Nile B. Ogaden B. Wabishebelle B. Rift Valley. Omo-Gibie B. B-Akobo B. Aysha B. Genale-Dawa B.

7 Area and Discharge of the Basins Basin Name Area Water Resource Potential (approx) (billion m 3 ) Remark km 2 % Surface % Storage Ground Wabi Shebelle 202, Highly Flood Bearing Basin Abbay (B. Nile) 199, NA Genale-Dawa 172, NA Awash 110, Highly Flood Bearing Basin Tekezie 82, NA Gibie-Omo 79, NA 1.00 Highly Flood Bearing Basin Ogaden 77, NA Baro-Akobo 75, NA 1.00 Highly Flood Bearing Basin Denakil 64, NA NA Rift V. Lakes 52, NA Mereb 5, Aysha 2, NA Total 1,129, NA NA

8 Further Background: A Little about ERHA The Ethiopian Rainwater Harvesting Association (ERHA): A young organization established in 1999 and legally registered in 2001 in Ethiopia Carries the objective of promoting the application of RWH as a viable option to counteract the ever-mounting fresh water shortage problems affecting (in several ways) thousands of communities in the country Has over 210 multidisciplinary members (though the level of participation of many of them yet needs to be enhanced) General Assembly, Executive Board and a Secretariat form ERHA s governing and executing bodies Works in partnership with likeminded institutions such as: RAIN, SearNet, GHARP, WaterAid in Eth, UN-HABITAT, UNICEF, and others

9 ERHA (Cont d) RAIN: Rainwater International Network Found n, based in the Netherlands, stands out to be ERHA s closest ally, without the support of which, it would be very hard for ERHA to function the way it does today With the mutual understanding reached between the two and with financial and advisory support of RAIN, ERHA, since 2005, has been moving towards serving as a Rainwater Harvesting Capacity Center (RHCC) in Ethiopia RHCC is an initiative run based on annually renewed contract agreement between RAIN and ERHA, In a nutshell, the RHCC initiative aims to capacitate ERHA to be a center of excellence or a focal institution dealing with major strategic RWH issues in the country

10 RWH in Rural Schools: The Subject-matter In the last 10 years, schools have been mushrooming as a result of the government s major education programme, spurred by the recent economic growth The school expansion covers all parts of the country and all schooling levels (primary, secondary and tertiary) Access to school and student enrolments have shown unprecedented rise in all areas and at all schooling levels However, one of the main problems observed in schools is that quite many of them, especially the ones found in ASADL areas, are without water supply and sanitation facilities; even if they have any, the facilities are often improper, short-lived, dysfunctional or out of order,

11 RWH in Rural Schools (cont d) The water Sector Review Report (2006) indicates 70 % of the schools in the country lack or are without proper sanitation services, The report also indicates that, not only schools but also health facilities (about 30 % of the existing health centers, 50 % of the health stations and 70 % of the health posts) experience acute problem of lack of basic sanitary facilities, notably latrines, The lack of basic sanitary facilities is a proxy indicator for the lack of water supply facilities as well Eventually, child mortality in the country reported to be one of the highest in the world (about 250,000 per annum) as a result of diarrhea diseases induced by insanitation and unhygienic conditions Obviously, in terms of priority, the problem is most pronounced in the low-lying drought prone and moisture deficient areas, which altogether constitute over 60 % of the country's landmass.

12 So Why RWH in Schools in ASADL Areas? Although RWH is needed almost everywhere in the Ethiopian context, it is an intervention of highest priority in ASADL areas. This is because ASADL areas: receive meager precipitation (seasonal rainfall), are characterized by hot environment demanding a lot of water consumption, especially for drinking have no other better/alternative water supply sources to get sustainable service from If schools lack such basic WSS facilities, the risk of children being vulnerable to different kinds of diseases and the potential of certain disease outbreaks remains quite high (e.g. AWD a case in point!).

13 Why Lack of Other Alternative Sources? Let s examine the characteristics of conventional water supply systems, which can be broadly categorized into two, surface and ground Surface water supply systems commonly consist of component parts: dams, reservoirs, treatment plants, conveyance lines/pipes, gravity tank(s), built on raised grounds, distribution lines, and public fountains (distribution points),

14 Why Lack of Other Alternatives? (cont d) Similarly, groundwater supply systems comprise of component parts : wells (including drilled deep-wells or boreholes, drilled shallow-wells and hand-dug wells), motorized pumps (mounted on boreholes and shallow wells) or hand-pumps (mostly fixed on hand-dug wells and possibly on shallow-wells), raised/tower tanks, treatment units, and distribution points. As a result, these systems : are mostly too complex/sophisticated both in the design, construction and management phases are highly costly both in initial investment and operation

15 Why Lack of Other Alternatives? (cont d) are prone to frequent failures are centrally managed by authorized institutions and not manageable by the end-users themselves Moreover, geological and chemical problems (well collapse, fissure, salinity, fluoride, arsenic, etc) are widely reported to be other major limiting factors associated with pumped groundwater systems, Also, high evaporation and seepage losses as well as silting problems are common challenges faced with surface water supply systems involving dams and reservoirs All these constraints often undermine the feasibility, effectiveness and sustainability of conventional water supply systems, especially in the arid and semiarid pastoral (ASADL) areas of the country.

16 Why Lack of Other Alternatives? (cont d) Furthermore, whatever public water supply plans exist in ASADL areas, they often target settlement or residential locations, schools having little chance of being included in the plans Therefore, given all the above, it is unlikely to address the water needs of ASADL communities in general and the schools therein in particular using only conventional supply systems and within a reasonably short period of time

17 RWH as a viable option Here the importance of RWH comes in as a viable option that cancels out most of the limitations seen with the conventional water supply systems The primary objective of RWH in schools is to meet the basic water demand of the school communities for drinking, sanitation and hygiene purposes, RWH can be initiated in schools in three cases: either to augment existing (but poor) water supply systems, if any in the target schools, or to establish new systems for human use, if there are no any, and/or to help schools establish and engage in important demonstration/developmental activities (such as gardens, etc) depending on the availability of resources The main problem/challenge of RWH is the difficulty of attaining dependable quantity and permissible quality of water in a sustainable manner But, both of these issues can be fairly captured through proper planning, design and management strategy of the schemes.

18 RWH Design Considerations for Human Use Determining amount/quantity of water (demand & supply) : The demand (D) can be estimated using the following simple formula: Where: D = r x n x d D : Total demand/requirement for a given duration (in liters) r : Minimum per capita requirement (for drinking, sanitation), in liter/head/day; n : Number of people targeted for the scheme; d : Duration of time for which stored water supply is needed during the year, (in days).

19 Design Considerations (cont d) Determining supply (S): The amount of rainwater that can be collected (i.e potential supply) It is a function of the amount of rainfall (f) in the geographic area under study and size of the catchment area (a) and can be estimated using the following empirical formula: S = c x a x f/1000 Where: S : Total supply (rainwater that can be generated), in m 3 ; c : Coefficient of runoff taking care of friction/seepage loss, (may be taken up to 90%, depending on the surface condition of the catchment areas), a : Catchment area size, in m 2 ; f : Total amount (depth) of rainfall in the area for a given duration, in millimeter (mm).

20 Design Considerations (cont d) Quality issue: Appropriate/simple protective methods as well as affordable but effective treatment methods should be employed for keeping the water safe for consumption. The protective methods may range from regularly cleaning the catchment areas (rooftops and others, if used) to employing different mechanisms, such as first-shower excluder or washout pipe (with end cap or gate valve) on the gutters, and a filtering unit on or adjacent to the tank. Draining and washing storage tanks cyclically, just before the tanks are recharged with new rainwater every next season Such protective measures, if employed properly, would maintain the cleanness of the stored rainwater. If they are not used at all or are defective, the stocked water may get dirty, change its color and smell bad, becoming contaminated and completely unsafe for human use.

21 Design Considerations (cont d) Appropriate treatment methods have also to be applied for ensuring the safeness and reliability of the stored rainwater for drinking Here, routinely supplying necessary disinfection inputs is challenging operational/sustainability issue One alternative maybe the use of non-chemical treatment/purification mechanisms or non-industrial products For instance, the integration of well-designed slow sand filtration systems with the RWH structures is an effective way, particularly for small water supply schemes, which may arrest up to 99% of pathogens in raw waters

22 I THANK YOU ALL!