Water and Sanitation in Emergencies - Good Practice Review 1 (ODI, 1994, 120 p.) 7. Typical Scenarios 7.1 Introduction 7.2 Population displacement into arid areas 7.3 Population displacement into hilly and mountainous areas 7.4 Population displacement into areas of abundant surface water 7.5 Population displacement into existing settlements 7.6 Resident population affected by drought 7.7 Resident population affected by sudden-onset disasters 7.8 Emergency water and sanitation programmes in urban areas

Water and Sanitation in Emergencies - Good Practice Review 1 (ODI, 1994, 120 p.)

7. Typical Scenarios

7.1 Introduction

This Section presents seven scenarios which are broadly representative of the majority of emergency water and sanitation situations faced by relief personnel. It also indicates the particular considerations that need to be taken into account in these situations.

The principal benefit of such an approach is that information can be conveyed in a way which is more accessible to non-specialists than would be possible using a more generalised approach. However, there are drawbacks to the approach and it is important that readers should be aware of them. First, a few 'typical' scenarios cannot cover all possible types of situation likely to be faced by field staff. Second, scenarios which are typical are not necessarily mutually exclusive. However, it is hoped that readers may be able to find information relevant to their own circumstances which will help them to participate in discussions on the design and implementation of emergency water and sanitation programmes.

7.2 Population displacement into arid areas

Water Characteristics. Arid regions often pose the greatest difficulty for emergency water supply to displaced populations, for by definition the areas are dry. The long-term options are either to move the camp closer to a reliable water source or to develop an independent water source close to the camp. Both are likely to be slow processes. The short-term options may include bringing the water to the camp by lorry (water tankering) and maximising the use of local sources found in the area.

Section 5.2, under the heading Creating New Sources, discussed the technical complexities associated with developing a borehole supply. Nevertheless, borehole sources can and, all around the world, do provide good quality and reliable quantities of water in emergency situations. However, some other issues arise from the use of boreholes, which can be particularly important for the resident population. An illustration from the Twareg refugee programme in Mauritania in 1992 illustrates this point very well (see Box 10).

Box 10 Borehole Sources in Mauritania In a very arid area the only option for supplying water to the refugees was from deep boreholes. The boreholes were 125m deep. Near to Fassala Nere camp, there were some traditional hand-dug wells of 60m depth, which were used by the local population. Within a few months of the boreholes being operational, locals within a few kilometres radius of them started to complain about their wells drying up. This was almost certainly as a direct consequence of the rate of borehole extraction. In such instances, me volume of water being drawn from me aquifer is greater than the rate at which it is recharging. This inevitably leads to the water level dropping. Hence, the local wells were drying up. The only thing that can be done to the wells is to deepen them. At 60m below ground level, this is a complicated task.

Establishing a high volume water source in an arid area can also interfere with local agricultural systems and cultural practices. Again in Mauritania, local nomadic practices were interrupted by the borehole water. The opportunity of reliable volumes of water all the year round acted like a magnet drawing large herds of livestock to the area. This had disastrous effects on the vegetation. Animals were grazing the same area for prolonged periods and, whereas previously, grasses would be grazed to ground level, roots were now being eaten, with direct consequences on soil erosion and stability. By relying on a single water source, people were jeopardising their future ability to sustain their traditional agricultural practices.

Sanitation characteristics. Much of the discussion in sections 6.1 AND 6.2 will be relevant here. From the point of view of sanitation, arid areas are well suited as space is not usually such a limiting factor and hot, dry climates are naturally better at inhibiting the transmission of faecal-oral diseases when open defecation habits are practised. Unless the soils are rocky and/or shallow, the scope for digging pit latrines is also good. If it is a desert environment, it is probable that construction materials such as wood, sand, gravel and cement will be in short supply. Reliable sources for the supply of these materials will need to be found.

7.3 Population displacement into hilly and mountainous areas

Water characteristics. Very often in mountainous or hilly terrain the issue is not so much where the water is to come from, but how to get it to the population. As always, it is very important to consider the proximity of water when choosing a camp site.

Water is usually found in the valley bottom in the form of a river, lake or as groundwater. Sometimes it will surface through a spring-line, i.e. above ground level where it is forced out of the hill side because an impermeable layer prevents further downward flow. If luck is on your side, a spring-line may exist above the level of the camp site. This will allow the water to flow by gravity through pipes to the camp. However, such a situation should by no means be taken for granted and every effort should be made to identify a reliable water source before the site is chosen.

If a hilly area is populated, it is the valley bottoms that will be either cultivated or inhabited. In either case, there will be enormous competition for land, and it is unlikely that land for a camp site will be able to be negotiated with the local inhabitants. This will dictate that the site is either on the slopes of the hill or at the top. Its exact location will depend on the slope, which is important because if it is very steep people will not be able to live there, and access for agency vehicles might be difficult.

When people are living at a significant height above a water source the agency is faced with a major decision: should it pump the water up to the people or ask the people to walk down to the water? Before making this decision, what is entailed in taking water to the camp should be clearly understood, as significant pumping will be required. It is not impossible to pump water to considerable heights but the system is difficult and expensive, and it does take a long time to install. The running costs are also high and generous budgets should be allowed for this.

On the other hand, asking people to walk long distances down steep slopes to collect their water is also far from ideal. The extent to which this can be expected of them will depend upon how they usually collect their water. If they are from a region where they normally walk downhill for their water, this will be nothing new to them; if they are not, then problems will be encountered when trying to persuade them to collect sufficient water on a daily basis.

If people are being asked to collect their water from difficult access points, it is more important than in other situations to ensure that they have adequate means of transporting it. The emphasis is always on increasing the amount of water used and so, if people are to walk long distances for their water, it should be worth their while. In the same way, means should be made available for storing water within the shelter so that there is always the opportunity to have one vessel available just for transporting water, whilst another is used for storage. This usually means providing jerry cans and they may not be readily available in the particular country or region. Local alternatives, such as clay pots, will be in use and may be available on a reasonably large scale. Narrow-necked containers are preferred as they help prevent the ingress of air- or hand-borne contamination.

Obviously the decision about pumping water a long way uphill will be influenced by a number of factors, including the predicted length of stay and the number of camps being considered. In Rwanda, for example, during the Burundese refugee influx in October 1993, there were up to 30 camps needing water. Funding for this was limited and would not have met the full cost of pumping water into all the camps. This gives rise to another question. If there are large numbers of people and providing water is going to be a problem, is it better to leave people in small settlements near to water sources such as springs, or to gather them into a large camp where substantial expenditure on a water system can be justified? If small settlements are preferred, this may mean that the provision of other services such as health care may be more complicated than in a large camp, but note should be taken of the fact that people have to collect water daily and the effort required to do this should, where possible, be kept to the minimum.

Box 11 The Central African states of Rwanda and Burundi have a topography and population densities which typify all that is difficult about providing water to displaced and resident populations in hilly conditions. Since February 1993 and until the outbreak of civil war in April 1994, a great deal of effort has been devoted to providing water to hundreds of thousands of internally displaced and refugee populations in Rwanda. There is virtually no free land available for displaced persons' camps in the most densely populated country is Africa. The problem was always how to get water to the people and almost always the answer was to provide better collection and distribution points close to the spring site, whilst encouraging increased use and collection of water. Important in this context is the role of hygiene awareness amongst the population. There needs to be a valid reason in their own minds as to why they ace being asked to expend huge amounts of time and energy collecting more water man they may have been used to.

Sanitation issues relate to the slope of the ground and the influence latrine siting can have on water quality, and also the depth of soil.

Digging a hole for a pit latrine can be a more complicated procedure on a slope than on flat ground. The ground needs to be levelled off so that a squatting plate can be installed, and care must be taken to ensure that the risk of pit collapse is minimal; good drainage around the latrine structure is also essential. Water must be diverted away from the pit, not only to prevent pit collapse, but also to ensure that rainwater does not prematurely fill the pit and cause it to overflow.

The depth of the soil is another important factor. The sides and tops of hills often have very little soil cover. This will cause problems, as it will not be possible to dig sufficiently deep pits. Alternative sites can be identified, but other local constraints may limit the possibilities. In this case, engineering solutions need to be explored. The most readily achievable solution will probably be to dig the pit as deep as possible and then to add extra storage capacity by extending the structure above ground level. In other words to create a sealed chamber above ground level. Another option might be the regular emptying of shallow pits - known as desludging - and transportation of the material to other disposal sites.

If defecation areas are to be used during the first stages of the camp's development, consideration must be given to the relationship of the areas to the camp and water source. If a defecation area is sited above a camp, when it rains all the faecal matter will be washed into the camp. Similarly, if an area is above an open water source, such as a river or lake, the excreta will be washed directly into the water that people are collecting for domestic use. This will severely affect the health status within the camp. During the Burundese refugee influx into Rwanda in 1993, at the very early stages of the development of one camp, open defecation was the practice both inside and around the camp. The camp was on a very steep slope. The only water source nearby was a marshy area immediately below the camp, which in itself offered a poor and polluted source of water. The rainy season had just started and every time it rained, excreta were washed directly into the marsh. This camp was to have the highest incidence of dysentery amongst all the refugee camps.

Care must also be taken when siting latrines if the camp is above a spring or springs which are being used for the provision of water. Just as excreta can be washed down a hill and into an open source, so they can move through the soil and into spring water. Exactly how water will move below ground level in any given area is very difficult to predict. However, to minimise the risk of contamination, the maximum possible distance should be maintained between the latrines and the spring. It is difficult to be more specific than this. Text books always say that latrines should not be sited uphill of a water source and should be at a minimum linear distance of 30m. This allows a margin for natural sub-surface filtration and bacteriological activity to act on the liquid from the latrine.

7.4 Population displacement into areas of abundant surface water

Water Characteristics. Surface water sources can offer good scope for supplying large quantities of water of acceptable quality very quickly. However, it needs to be recognised that introducing a technology aimed at treating a surface water source will make the system fragile, vulnerable to disruption and reliant upon expensive chemicals. It is highly improbable that a community will be able to sustain a water supply from such a source once the emergency is over or after the relief agencies have left the area. As such, notions of providing a resident population with a water supply after the emergency has ended are unrealistic. If local conditions allow, it may be appropriate to look at the options for a two- or even three-phase water supply programme.

The first phase may be tankering water from a good quality source. This can be done, whilst second-phase surface water installations are being developed closer to the camp or settlement. The third phase might involve developing alternative sources such as hand-dug wells or tubewells for a long-term water supply. The ability to move on to the third phase will be totally dependent upon the nature of the soil and the groundwater in the area.

If water is to be drawn from a river, it is very important that it is drawn upstream of the nearest centre of population. This will reduce the chance of high levels of human contamination in the raw water.

The methods discussed above can apply equally to lake water. In Burundi water from lake and marsh sources is currently supplying refugees and returnees.

Box 12 Slow Sand Filtration was used on the Rohinga refugee programme during 1992 in Bangladesh, where its use was of particular interest because the normal method of water supply in the region was via tubewells. The geology around the Dumdumia camps prohibited and surface water sources had to be used. SSF provided water to one of the camps whilst sedimentation and flocculation of water drawn from behind a purpose-built dam supplied another camp. The dam was constructed to capture the flow of a small stream and additional flood waters and illustrates how the maximum use can be derived from a small flow of water if the surrounding topography permits.

As discussed in Section 5.2 under Treatment, infiltration galleries can be very effective at cleaning a turbid lake or river source. However, this is a time-consuming operation and caution needs to be used when planning the exercise, as experience in Rwanda in 1993 illustrated. It was only after the work had been completed and water was flowing into the collection gallery that it was realised that the gravel which had been used as the filtering medium had a very high iron content and was affecting the taste of the water, making it unpalatable. This was not crucial at the time as there were alternative sources of water available to the camp of 80,000 people and the fall-back option was to flocculate the river water. As stated earlier, experimentation should be encouraged.

Water supply systems will always require maintenance and therefore management. The more complicated a system is, the more management it will require. Treating surface waters is a complicated means of providing water and demands considerable managerial and logistical support. This must be recognised before responsibility for the construction and operation of such a system is accepted. Efforts should be made to standardise the equipment. For example, if diesel-powered centrifugal pumps are being used, the type and specification should be standardised as much as possible across the programme. This will assist with maintenance programmes as central workshops can be established for a number of camps, and when ordering spare parts. A record should be kept of engine and pump serial numbers to help with spares orders, and a record of each pump's service history will assist when planning replacements. Whenever possible, the preference should always be to standardise on equipment that is installed and available locally. This may mean that equipment which was initially imported for the emergency will be replaced by local purchases.

Box 13 An extreme example of the problems created by a high watertable dictated a very complicated latrine design for the Bhutanese refugee camps in South-Eastern Nepal. In a number of me camps the watertable was less than 1m below groundlevel during the wet season. Latrines were to be provided at a ratio of 1 latrine for every two families. Space was limited in the camps and so it was not possible to gain the required storage capacity by making wide shallow pits. One suggestion was to install a piped sewage system which would deliver waste to treatment ponds, but this was considered inappropriate in the circumstances. The solution adopted was to provide fully lined twin-pit latrines. Each of the two pits under every latrine was designed to contain storage capacity for the number of users adequate for one year's use. The principle was to use one pit for a year, seal it over and use the other the next year. During the time when the first pit was sealed, the sludge was to be rendered safe for handling and at the end of me second year was to be emptied; the first pit was men reused for the mild year and so on, in theory indefinitely. In order to provide the capacity for one year's storage whilst keeping the pit out of the watertable, it was necessary to raise the pit lining above ground level. This is the key to gaining additional storage capacity for pit latrines when either high walertables or shallow soils limit me depth to which the pit can be dug.

Sanitation Characteristics. In areas where surface water is prolific, the position of the watertable below ground level is of special relevance. If the watertable is close to the surface, work on a sanitation programme may have to pay particular regard to this. Clearly if the watertable is 4m below ground level, digging pits for pit latrines to this depth will contaminate the groundwater; this must be avoided. As a guideline figure, 1.5m between the bottom of the pit and the highest level of the watertable should be sufficient to prevent contamination of the groundwater in fine soils. These limitations will reduce the storage capacity of the pit and hence its design life. This in turn may have implications for the design of latrine to be used, as consideration may need to be given to the possibility of resiting latrines or regular desludging because of lack of capacity.

7.5 Population displacement into existing settlements

Water Characteristics. When there is a movement of people into an existing settlement there will inevitably be an additional burden on the existing water supply. The capacity of the system to cope with this demand will determine the need for assistance measures. The most obvious intervention is to look at ways of expanding the existing system or obtaining the maximum yield from it. In the case of a pumped water supply, this may simply mean increasing the hours that the pump is run. If it is a gravity flow piped system, it may be possible to consider additional storage to capture flow that is wasted. Simply providing extra collection points will have the effect of reducing waiting time, particularly during peak demand hours. If the regular supply is from wells, there may be wells in the area that have fallen into disrepair; it is not uncommon for open wells to become redundant simply because stones have fallen, or been thrown, into them. If this is the case, simply clearing the obstacles could make the well serviceable again.

If the existing system clearly cannot cope with the additional numbers of people, it will be necessary to find short- and medium-term alternatives. Tankering water can provide an immediate response, whilst medium-term options are being surveyed and installed. In the situation of an existing settlement, there is an even stronger case than elsewhere for making the emergency water system as appropriate as possible so that it can offer the resident population new opportunities once the emergency is over. Thus, for example, if a village is dependent upon wells, providing additional wells would be an appropriate and, and it is to be hoped, sustainable solution. The opportunity can be taken to reinforce local management structures by offering training on maintenance, and by incorporating community management systems into the new programme.

In these situations, it is very important to be sensitive to the local population's needs. It seems only reasonable that, if systems can be provided that offer them something in the long term, those options should be chosen.

Box 14 In North Kivu Province in Zaire, the region currently hosting 1 million Rwandan refugees, the displacement of 200.000+ people in May 1993 caused particularly difficult problems. Most of the displaced people moved into villages of the same ethnic background where they felt safe. Consequently there were large numbers of small clusters of people in villages which themselves had serious water supply problems. Apart from a few large piped water schemes, the Province had attracted very little in the way of water supply development programmes. At a village level, water was typically collected from unprotected spring sources or streams. To exacerbate the problem, many of the villages to which people had fled were on volcanic rock where water retention is poor, and unprotected spring sources posed a major health hazard since very little sub- surface filtering takes place. A number of agencies saw a spring protection programme as offering the fastest response to the large number of settlements. One agency also decided to integrate the spring protection with a hygiene awareness programme which included community mobilisation to construct and use improved latrines, the promotion of basic hygiene practice, and the use of community health workers - all very important in an area where cholera is endemic. This is an example of a response to an emergency situation where an attempt was also made to address longer-term community needs as part of the same programme.

Sanitation Characteristics. When displaced people move into existing settlements, they will frequently occupy public buildings such as schools. These will usually have some sort of basic or improved latrine provided, but the large number of additional users will almost certainly result in overfull pits or septic tanks. In these circumstances, it is not uncommon to see effluent from the latrines washing over areas around the buildings. This is totally unacceptable. Measures need to be taken to clean this up and prevent it happening in future. One option may be to undertake a regular programme of desludging, as was done in Mazar-i-Sharif in northern Afghanistan in 1993 when people displaced from Kabul occupied schools and university buildings in the city. If a piped sewage system exists in the area it may be possible to connect the latrines from the public building to this, as is currently being explored in Bujumbura in Burundi where people displaced by fighting in October 1993 have occupied schools which were not connected to the city's sewage system.

7.6 Resident population affected by drought

Droughts result in a reduced yield and the possible drying-up of traditional surface and sub-surface water sources. Households (usually the female members) have to travel longer and longer distances to obtain water from reliable sources. As yields are reduced and the remaining sources are overused, so the quality of the available water tends to deteriorate. Ultimately, households and communities are obliged to migrate to better quality and more reliable sources. The use of poor quality sources, the stress of the move to better quality sources and the concentration around them often result in increased morbidity. National and international responses to drought invariably focus on the provision of food and it is often difficult to mobilise resources for water sector activities.

Water Characteristics. A broad range of interventions is available when responding to drought in rural areas. In considering the most appropriate intervention, it is important to bear in mind its likely time-lag and the chances of its relieving water stress in the affected communities before the start of the next rains which will herald the end of the drought. Some interventions are unlikely to have an impact during the drought but may, if managed properly, improve the reliability of water sources during subsequent droughts.

In situations where water is normally head-carried and the drought necessitates the use of more distant sources an appropriate intervention may be to assist communities with the transport of water. This might involve the provision of animal-drawn water cans and, if necessary, the animals to pull them. This action would enable one individual to collect water for several families and thus save the time and effort of the women who would normally head-carry the water. In more difficult terrain, wheeled carts may be inappropriate and the provision of animals and water containers which can be strapped to their backs may be more appropriate. Such interventions need not entail the free provision of animals and equipment but could be managed on a loan basis or credit should be provided to water traders to enable them to expand their activities. Care would need to be taken in selecting those to receive the loans and in ensuring that they did not unduly exploit their position by overcharging for the water transported.

Where institutional capacity permits and the affected communities are many miles from reliable sources, it may be more appropriate to tanker water to them either by lorry or by tractor-drawn water-bowsers. Such interventions were undertaken by District Councils in Botswana during the extended drought of the 1980s for those villages where boreholes had dried up. The advantage of bowsers is that they can be left standing in a central location for use by the affected community whilst the tractor or lorry goes off to pull other bowsers to other affected communities, returning to the first community with a full replacement bowser a few days later. It would be uneconomic to leave tanker lorries standing for several days, and for communities serviced by tankers a centrally located reservoir will need to be constructed serving adjacent standpipes which can be regularly replenished by the tankers. Butyl rubber water bags (known as bladder tanks) on raised platforms or earth banks are well suited to this arrangement. Such a system was used in Lesotho during the response to the 1991/92 drought. (Section 5.2 provides additional information on tankering problems)

The yield of wells which are drying up as a result of the drought may be increased by well deepening. This may involve the provision of tools to villagers or the employment of local well-construction companies/artisans. (see Section 5.2).

In countries where government agencies are responsible for the maintenance of water supplies and where capacity has been in decline as a result of broken pumps and lack of spare parts, the rehabilitation of faulty equipment on existing sources would be more appropriate than embarking on the drilling of new boreholes. Supporting the responsible government agency by the provision of the required spare parts, transport for technicians to visit and repair the faulty equipment and perhaps technical assistance would be appropriate. In some instances it may not be possible to work with the government agency and the relief agency may have to undertake the rehabilitation work itself.

Finally, there is the option of drilling and equipping boreholes. This represents a high tech approach which might be attractive to donors. Borehole drilling programmes as a response to drought related emergencies have been of limited success but continue to be a commonly employed response to water problems in drought affected areas. Relief agencies need to be aware of the technical and institutional reasons why this may be the case and to ensure that all other options have been considered before resorting to a borehole drilling programme.

New drilling rigs are unavailable in most developing countries and therefore need to be imported. This may take months, with the result that the drought will have ended by the time the rigs begin operation, and it will be even longer before successful boreholes are equipped and functioning. The rigs are usually enormously over-specified and consequently very expensive. Rigs capable of drilling to depths in excess of 200m may be ordered for situations where it is only necessary to drill to less than 100m. (See Section 5.2 for more information on borehole drilling and equipping.)

Over the last few years a number of small, portable rigs have become available. Lightweight rigs manufactured in Thailand are currently working successfully in Cambodia. Similar rigs available in the UK cost from (approximately) $15,000. Their small size means that they are transportable by air. As with all drilling rigs, spare pans, consumables such as drill bits, casing and technical support need to be readily available to ensure sustained drilling.

Box 15 An evaluation conducted by a bilateral donor of its response to the Southern African Drought of 199/92 found that most of the expenditures in the water sector in three of the affected countries bad no impact on the water stress being experienced before the start of the next rains. The only activities to have had an impact before the rains were tankering operations. None of the well-deepening and borehole-drilling activities which had accounted for the bulk of expeditures had any impact before the next rains.

Low success rates should be expected in emergency drought relief programmes because of the difficulty of finding sufficiently productive boreholes in terrain that is probably hydrogeologically difficult and often problematic for drilling. For instance, in a programme in the Lebowa area of South Africa during the 1991/92 drought 73 boreholes were drilled over a 6 month period but only 25 were successful - a success rate of only 34%. The drilling of new boreholes may also be inappropriate because the pressure of the emergency reduces the quality of the work, resulting in sources which are poorly sited and equipped. In the Lebowa example engineers had to grapple with problems inherited from water systems constructed during a previous drought. At that time the government had imposed time limits on the use of emergency funds, the work was rushed and the systems were poorly designed and constructed and required remedial maintenance and repair⁸.

⁸ J. Davis - personal communication.

From the above it would appear that the use of temporary, stop-gap measures such as transportation and pre-drought mitigation measures aimed at improving the reliability of water sources during drought periods are to be preferred to 'quick-fix' solutions. A planned programme of infrastructural improvements in a drought-prone area is more likely to produce better supply systems at a lower cost than quick-fix emergency remedies.

Sanitation Characteristics. The reduction in water quality and availability associated with a drought means that people's consumption of water will decline, and this reinforces the need for good hygiene practices. People need to understand the relationship between personal and communal hygiene and the incidence of diarrhoea if they are to take measures to protect themselves. Agencies responding to the drought should complement their efforts to relieve water stress by running community-based educational programmes emphasising the importance of good hygiene practices. Such programmes may have as much, or greater, impact on the morbidity and mortality associated with the drought than more costly efforts to increase the volumes of water available.

7.7 Resident population affected by sudden-onset disasters

There are a wide range of natural hazard types in the 'sudden-onset' category and thus considerable variations in impacts in terms of water and sanitation. The principal sudden-impact hazards, in terms of mortality and numbers affected, are floods, cyclones and earthquakes. These are dealt with briefly here as the wide variation in context and impacts serves to discourage the development of notions of good practice, and it is likely that relief agencies and communities in known hazard-prone areas have experience of previous hazard events and are aware of most of the appropriate interventions.

The principles of providing people with safe drinking water and a safe means of disposing of their excreta apply equally to these situations. The population affected by such disasters will want to stay as close as possible to their homes; it is unlikely that camp situations will spontaneously occur and so the need for concentrated services will be less pressing. This will impose a different kind of burden on the agencies providing the service as they will have to start up a number of separate programmes in a number of discrete locations aimed at meeting the needs of disparate groups of people. This will obviously have staffing and resource implications.

Floods

Flash floods can cause intense damage on hill sides in hilly areas but the impact is usually localised. Floods are generally confined to valley bottoms and low-lying areas, where they prevent access to existing water sources and pollute them. People are forced to seek temporary shelter on raised ground where they will be obliged to use the polluted flood water for drinking and where the observance of minimum sanitation standards will be difficult. When the flood waters retreat the priority needs are to clean and rehabilitate the traditional water sources.

Water and sanitation. Providing all the groups on the raised ground with good quality drinking water for the period of the inundation will be extremely difficult unless the affected area is small, reliable water sources are available within or near to the affected area, and the relief agencies possess the means of transport (fast small boats, helicopters) for moving quickly between the concentrations of population. Where these conditions do not apply, it will not be possible to reach large sections of the population before the floodwaters retreat. In areas which are highly flood-prone, it would be desirable to protect traditional sub-surface water sources from the floods. In Bangladesh, for instance, many tubewells have been equipped with sealed raised plinths on which the handpumps are placed in order to raise the pump above the expected flood level and prevent the ingress of polluted flood water into the borehole. A complementary preparedness measure would be to equip the population for such events by providing them with the knowledge and means of treating drinking water drawn from polluted floodwaters. Fast-dissolving chlorine tablets are often distributed but their impact upon morbidity statistics is unclear, illustrating the difficulties faced when trying to educate people about water treatment methods employing chemicals.

The populations on the raised ground should be encouraged to observe basic sanitation standards and to adhere to the principle of burying their faeces. Even if defecation areas are sited above the floodwater levels, rain storms will wash faeces into surface water sources and inundated groundwater sources such as wells and boreholes. If sufficient land is not available for managed defecation, then defecation should be strongly encouraged at the furthest downstream point on the raised land.

Once the floodwaters retreat and people are able to return to their homes it will be necessary to rehabilitate the traditional water sources by cleaning polluted sources and repairing any damaged pumping equipment. Boreholes may be cleaned by flushing out the polluted water with water from a clean source or by repeatedly disinfecting the borehole and pumping it out. The quality of water in ponds used for household activities other than drinking can be improved by emptying the polluted water and allowing recharge from rain and through the restoration of the watertable.

Cyclones

Cyclones affect water sources in several ways. Surface instillations such as pumps may be damaged by the high winds and flying debris and electrical pumps will be rendered ineffective by the disruption of power supplies. In low lying coastal areas cyclones frequently cause flooding and saline incursion.

Water and sanitation. It is likely that survivors will want to stay as close as possible to their homes and villages; large concentrations of displaced people are therefore unlikely. The priority is to rehabilitate the damaged and polluted water sources, by repairing/replacing the pumping equipment and cleaning out the polluted/saline boreholes. Whilst this is being done, efforts should be made to ensure that the water being consumed is as clean as possible. Options include the distribution of fast-dissolving chlorine tablets; setting up filtration systems; transporting drinking water to the affected communities by tankers or tractor-bowsers; and ensuring that the risk of additional pollution to the water sources being used is minimised through the use of upstream and protected sources. If the area is highly cyclone-prone, preparation measures may have included training people in the correct use and application of treatment methods, the simplest of all being to boil water. Dead bodies and animal carcases should be buried and where populations have congregated pit latrines should be constructed.

Earthquakes

Earthquakes make large numbers of people homeless on a temporary or longer-term basis, rupture piped water supply and sewage systems, and damage reservoirs, pumping equipment and boreholes.

Water and sanitation. The population rendered homeless will probably settle spontaneously on the outskirts of the village/town or in camps. The priority will be to provide them with clean water (either through tankering, the repair of the damaged supply system or treatment of polluted sources) plus the usual sanitation measures such as establishing managed defecation sites, latrine construction and hygiene awareness training.

Earthquakes can damage household latrines and, in towns, rupture sewage pipes resulting in sewage flowing into the streets. These areas should be cordoned off and steps taken to prevent or reduce the pollution of surviving water supply systems.

Water treatment activities may involve the construction of temporary water treatment stations and the distribution of quick-dissolving chlorine tablets. If the region is highly earthquake-prone, preparation measures may have trained people in the correct use and application of these tablets.

Once the immediate objective of providing people with good quantities of reasonable quality water has been met, the water programme must then facilitate the return of people to their normal supply source as soon as possible.

Immediate and medium-term needs are not necessarily mutually exclusive and work on both can be simultaneous if resources allow. If communities previously relied upon piped water supplies, a quick solution is unlikely and medium-term reconstruction programmes will be required. Earthquakes will cause major land upheaval and it is highly probable that groundwater sources will also have been affected. Spring-lines may have been altered, wells can be irreparably damaged and boreholes can collapse. In such circumstances a speedy return to normal supplies is unlikely and the emergency solutions may need to be continued for a period of months or even longer. The planning of emergency interventions should anticipate the period over which they are likely to be required.

7.8 Emergency water and sanitation programmes in urban areas

The question of emergency water and sanitation responses in urban areas is raised regularly. In recent years the problems in the former Yugoslavia, the former Soviet Union and Iraq have been very high-profile. This Section briefly reviews some of the issues which NGOs need to consider in deciding whether or not to become involved.

Probably the first thing to consider is the scale of the problem. Providing water and sanitation facilities to 200,000 people in a camp easily is more achievable than trying to provide them to 200,000 people spread across a town or city. The level of technology employed in any urban system is likely to be high. As discussed in Section 3.3, the technical knowledge of how urban water and sewage systems operate needs to be available to the agency. Large-scale funding will be required as specialist equipment will need to be replaced and, pipelines may have to be reinstated or rerouted. Previous experience in these situations has shown that technical problems which at first seem to be easily reconcilable and possibly the direct result of recent conflict, bombing, etc., are in fact long-standing problems due to poor maintenance and under-funding of local departments charged with managing the systems. OXFAM has learnt this the hard way in Iraq.

During the Gulf war, the approach adopted by the International Committee of the Red Cross and UNICEF in Iraq concentrated on serviceable installations. Both agencies made essential items available to the water boards which meant that most of the major treatment stations were able to continue to function⁹.

⁹ G. Nembrini, ICRC - personal communication.

When an agency embarks upon an urban rehabilitation programme, it must recognise the scale of the task it is taking on. The problems of a poorly maintained urban water or sewage system cannot be resolved by a small NGO as an emergency response. OXFAM was involved in the rehabilitation of the Phnom Penh water system, and spent 12 years working on it.

Involvement originally intended to be restricted to the water system may inevitably have to be extended to the sewage system also. Bombs do not discriminate between water or sewage pipes. Both will be broken. This will mean that as people continue to use their toilets, sewage will flow not only into the streets but also into the water mains.

It can be argued that the best emergency response in an urban situation is to provide water storage facilities around the town and bring clean water to them, probably by tanker. This will afford the opportunity to survey and take in the scale and complexity of the work which is needed.

In Monrovia, Liberia, the ICRC initiative decided that the city's piped supply system was too big for them to deal with. They have adopted the alternative approach of digging wells for people to use around the city, which has gone some way towards meeting the drinking water needs of the inhabitants. People also acknowledge the fact that they may have to boil or otherwise disinfect their water.

One aspect of providing water in urban areas that has not previously been mentioned is that of pollution. Unlike rural areas, surface water sources in urban areas are likely to be chemically polluted. If the use of such sources is being considered, simple treatment processes such as those outlined above will be effective only on microbiological and not on chemical pollution. Specialist advice will have to be taken for every situation encountered.

Most NGOs can only hope to provide temporary answers or to patch up the problems of urban rehabilitation. Alternative ways of addressing the emergency will probably have to be sought until large and better resourced agencies can resolve the large-scale needs of rehabilitation.