How to Make Water-Wise Roads

Transcription

1 How to Make Water-Wise Roads Authors: Steenbergen, F. van (MetaMeta); Woldearegay, K. (Mekelle Univeristy).; Beusekom, H.M. van (MetaMeta Circular Economy); Garcia Landarte, D. (MetaMeta Ethiopia) and Al-Abyadh, M. (Road Maintenance Fund, Ministry of Infrastructure and Highways, Government of Yemen)

2 Contents ABBREVIATIONS... III INTRODUCTION... 1 KEY ISSUES/QUESTIONS... 2 LESSONS FROM EXPERIENCES... 4 GUIDANCE FOR DESIGN/IMPLEMENTATION ROADS VS LANDSCAPE BOX 2: INSTITUTIONAL UPTAKE OF ROAD WATER HARVESTING IN TIGRAY, ETHIOPIA SCALING UP CONCLUSIONS AND STRATEGIC RECOMMENDATIONS ADDITIONAL RESOURCES/TOOLS FREQUENTLY ASKED QUESTIONS... FOUT! BLADWIJZER NIET GEDEFINIEERD. REFERENCES... 19

3 Abbreviations AFCAP Africa Community Access Programme NEPAD New Partnership for African Development PIDA Programme for Infrastructure Development in Africa UPGro Unlocking Groundwater Potential for the Poor

4 Introduction The 21 st century has a number of challenges; climate change, demographic expansion, poverty reduction and increasing pressure on resources. There is a drive to accelerate the development of infrastructure transport, energy, amenities to provide the basis for economic growth for the countries that were most left behind. Multifunctional infrastructure is an approach that promises to tackle several of the challenges at once combining multiple services from the same infrastucture. This how to do note describes one of the most powerful examples. It describes how roads, can be transformed for better use of surface and ground water, for flood control and erosion mitigation while at the same time delivering transport and communication services. In this way the high investment in road construction in many countries the number one or two of public investment - can render a much broader impact on livelihoods and economic development. Box 1: Road network expansion in Africa Road network expansion has long been a primary objective for African Countries, but appear to accelerate now. The incomplete trans-african Highway network project was already drafted in the The project indentifed transport corridors as the main strategy to boost trade and economic development. Several programmes such as the NEPAD and PIDA picked up the concept and are currently addressing highway expansion for the entire African country with a funding requirement of 25 billion USD until 2040 and more than km of modern highways. In addition there is a fast expansion of feeder roads in sub-saharan Africa, making up 80% of all roads and adding 60,000 km a year. The argument for combining road investment with water harvesting is strong. The main points to create water-wise roads are: Less damage to roads water is responsible for much of the damage to road damage (up to 35% in Ethiopia). Understanding runoff behaviour in combination with road alignments and road drainage structures, subsurface flows and land and soil properties can prevent costs in road maintenance and lead to less traffic interruption. No damage to landscape, i.e. less erosion and gully formation roads disrupt natural drains and creeks and change run-off patterns, often concentrating them across drains. If not done well this triggers erosion and deep gullies may develop rutting the landscape and depleting the soil moisture, formation. Floods and waterlogged areas are more like to occur. Combining road design and water harvesting structures can tackle the former issues. Preventing floods. If t run-off from roads is not managed, local flooding and uncontrolled sand deposition results, affecting the livelihood of those that happen to live close to the roads. On a basin scale roads particularly when they are on embankments compartamentalize the watershed. This can be used to change and slow down run-off patterns and attenuate floods. Most important, turning a threat into an asset: water harvesting from roads the water generated from road drainage, from springs opened up by road construction or the water and soil moisture retained by fords and road surface provides a valuable resource. Its use and capture should be maximized for groundwater recharge, for safeguarding soil moisture levels and controlling water tables and for storage for agriculture and stockwater. This note may serve as guideline on how to combine roads and water harvesting. The investment in roads in almost any country far exceeds that in local water management or watershed protection. Hence roads offer one of the larget opportunities to secure local water supplies, if done wisely and in an 1

5 integrated way. This document describes both the governance and proceses to combine road development with water management as well as how recharge, retention and reuse (3R) of water can be enhanced through improved designs. Figure 1 a-c: Damage from roads: gullying, water logging and sink holes 2

6 Key issues/questions There are two underlying questions to be addressed. 1. What is the scope of water harvesting in road development? The scope of water harvesting in roads is extensive and multifaceted. It covers matters related to road building, povery alleviation and rural development and rural roads links to development programmes. Road building Road construction is amongst the highest public infrastructure expenditure. In Sub- Saharan Africa alone, the invesment amounts to 7 billion USD per year (Briceño-Garmendia, Smits, & Foster, 2008), which is substantially higher than expenditures on water resource management. Current national road network expansion can be coupled with water harvesting and better use of surface and sub-surface flows. In this way road budgets can address water resource management on a watershed level in areas were infrastructure development is taking place. Ground water, poverty and rural development Rural roads construction linked to poverty and groundwater development is a matter which has been overlooked by governments, donors and international organizations. Road construction when combine with water harvesting can benefit groundwater resources for poor rural communities, namely for small scale irrigation, animal watering and household activities such as nursery gardens. Groundwater development has played a key role in boosting agricultural production and thus reducing poverty in many parts of the global South, particularly in Asia (Shah 2010). Very shallow groundwater is particularly important because up to a suction depth of 10 meter it is possible to lift groundwater with larger diameter low cost tubewells and treadle pumps, rope pumps or low cost diesel pumps making small holder irrigation as a route out of poverty possible. Roads and road construction are conventionally linked with the modernisation project of society and are viewed by planners as way to increase the mobility of isolated communities, facilitate market access and thus reduce poverty (Howe 1984; degrassi 2005; Fairhead 1992) but other dimensions and possible negative impacts tend to be ignored. Research by several scholars has highlighted the multi-faceted impacts of road construction (Wilson 2004; Demenge 2011). It has demonstrated that experiences of road construction can be highly uneven for different social groups and have diverse social, gender and environmental impacts. Furthermore, as discussed by the World Bank in the case of Ethiopia, road design can interfere with functioning groundwater systems, having adverse impacts on poor downstream users. Thus, road construction needs to be viewed as part of wider processes concerning socio-economic and ecological transformations that can have a range of outcomes for poor people (Demenge 2011). For this reason, optimal implementation of water harvesting from roads can mitigate potential negative impacts for rural communities while increasing water availability for agricultural and domestic purposes. Rural roads and links to development programmes Feeder-road programmes are often explicitly implemented to alleviate rural poverty. Rural road construction is often geared to employ landless and unemployed rural population. Governance arrangements can be improved to integrate groundwater recharge and retention in a cost effective way in feeder road construction, enhancing the potential of feeder road development for 3

7 poverty alleviation by creating (and not destroying) opportunities for productive and social use of shallow groundwater and improved soil and water conservation. In this regard development programmes related to food security, employment and rural access are key to broaden the impact feeder-road programmes on rural environments. Considering the scope of water harvesting in such context - the links to be established are multiple. 2. How to combine water and roads for better use of surface and ground water, erosion mitigation and reduce road maintenance costs? Institutional cooperation For road infrastructure to become truly multi-purpose, there needs to be close cooperation between those responsible for road development and those for watershed management and agriculture. Therefore cooperation among different institutional actors (road authorities, bureaus of water, agriculture, natural resources, etc.) involved in feeder road programmes and rural development would enforce multifunctional uses of rural roads. Inclusive planning processes Road planning processes in their current form rarely allow for the incorporation of broader multiple-function objectives, local perspectives or attention to poverty. However these processes can be modified to bridge this gap between road, water and agriculture sectors: at all levels and for all stakeholders, rural communities, NGOs and national and local governments depending on local institutional arrangements. To systematically include water harvesting in roads a more integrated, inclusive and dynamic framework for road planners and designers is required, allowing them to include: the manipulation of runoff in the design packages, moving beyond dealing with protective road drainage only; the adaptation of road design manuals, including the main parameters for changed road design; matching up with water harvesting programmes; and a different approach to site investigation and reconnaissance for instance, taking into account the location of recharge areas and the security and ownership of land. At the same time water harvesting from roads should be a standard element in watershed programmes, including the protection of sensitive road sections by those responsible for watershed protection. Complementary or co-financing programmes may be developed that increase value to both parties. Community Involvement Local communities need to be involved in the design phase, so as to indicate local water needs and alert different authorities and road designers on opportunities and constraints for water capture along roads. This will require a different style of working for road engineers, but it may go a long way in reducing the water damage to roads, now the single largest cost item in road repairs. Lessons from experiences Road water harvesting has been implemented in a number of countries, specially in arid and semearid environments. Some highlights are provided country-wise below: Yemen Rain water harvesting is an ancestral technique applied for centuries in Yemen. Some of these techniques have been implemented in road design as well. Rain water harvesting through 4

8 excavated, roof-fed and side drain cisterns; underground stone paved canals, water tanks; collection of drain water from culverts to fields, refilling of borrow pits and earth ponds are some techniques applied in rural and tarmac roads. Figure 2 a-c: Road Water Harvesting Pond and Feeder Canals Water is channeled through special water harvesting tanks, that dependent on public or community resources may be improved or lined. The channels leading to the ponds from the road culverts may be shaped to as to dissipate energy and prevent gullying. Figure 3a-e: Road side cisterns: excavated cisterns and roofed cisterns 5

9 Communities extend natural (limestone) water cisterns along roads in Yemen, using traditional hand tools During the scarce rainfall events the water cisterns are filled doubling up as cold storage. Water is being used for livestock watering in the dry periods. Other road water fed cisterns have reinforced roofs to reduce evaporation, and prevent human and livestock falling into the tank. Often the first run-off after a long dry spell is not allowed to enter, as this first water is contaminated and carries too much sediment. Typically, road water collected in the road side drainage ditch channel is managed by two small porter stones installed across the trapezoidal ditch channel. Mud, sand or a piece of cloth are used to block the gate and divert water to the cistern. During the first flushes and later - after the cistern is filled these temporary check dams are removed. Some cistern-road system include sediment trapping facilties by using overflow structures, thus skimming the cleaner top layer of water. Ethiopia In Tigray, as part of the UpGRO catalyst grant, Mekelle University, MetaMeta and IDS and other project partner have succesfully introduced road water harvesting in the regional agenda. Novel to many stakeholders, road water harvesting was applied sporadically but not systematically in the region. Recharge or storage using borrow pits, percolation systems such as deep trenches and percolation ponds meant to increase ground water recharge, side-drain drainage used for irrigation, sand mining, road-side earth ponds are some of the techniques already present in the region. The pictures below illustrate the existing road water harvesting techniques. Figure 4 a-b-c Road culvert discharge feeding infiltration trenches and percolation ponds 6

10 China 7

11 A range of road water harvesting techniques are used in China, representing the large variety of conditions in the country. The use of road side cisterns is popular in some of the drier areas of the country. In Gaomi (Shandong) the borrow pits for the foundation of the high speed railway are converted into local storage reservoirs with in a number of cases recreational functions attached to them as well. Figure 5: Borrow pit from high speed railway track converted to storage reservoir and local lake Kenya In Kenya low-cost sand dams have been widely implemented with the density of these sutructure higher in Kenya than anywhere else. Sand dams retain sand and silt deposits in ephemeral rivers. Sand trapped contain water which can be easily tapped and the presence of the structure also raises groundwater levels in the adjacent area. Sand dams can be combine with irish bridges or fords as serve both as river crossings and water retention structure at the same time. Other roads water harvesting techniques in Kenya are earthen charco ponds that maximize storage vis-à-vis the, water tanks and recharged borrow pits (Nissen, 2006) Figure 6 : Sand dam river crossing in Kenya (Excellent) 8

12 Pakistan Spate irrigation is widespread in the dry western parts of Pakistan, though often forgotten in the presence of the large-scale Indus irrigation system. Spate irrigation uses short term floods for irrigation, recharge or storage and hence make productive use of one of the most difficult water resources. For the succesful diversion of flood water low cost temporary structues such as soil bunds or stone deflectors are used. To construct these it is important that the river bed is stablized and not rutted and uneven. Low crest weirs have been constructed that are combined with the function of road crossing, so as to justify the costs. Figure 7: River bed stabilizer combined with roads crossing Niger Water spreading weirs combined with river crossings have been developed in dry rivers in several Sahelian countries, Niger in particular. Temporary floods are routed out of the dry river 9

13 beds so as to inundate the surrounding area. The river crossings as well as embanked roads leading to them act as flood spreaders. Drop structures and cross drainage is provided to the the water spreading weir so as to ensure their stability. Arid environments are thus regreened with forest and vegetation grass species. Figure 8: Water spreading weir river crossing also known as Seuil-radier (source Bender) Guidance for design/implementation Depending on landscape typology and land use, road water harvesting techniques will vary. Terrain: mountain, flatland or floodplains Roads are mayor interventions in the landscape, they dissect surface and sub-surface flows and concentrate runoff flows through side-drains, cross drains and culverts. Therefore factors like road location in relation to the topography, the steepness of cut slopes, the orientation and the grade of road pavements and the roughness of slope (rock, soil, vegetation, etc.) are matters to take into account. As a general rule road alignments should be set at toe-slopes ranging less than 40% gradient, thus making it easier to drain (Zeedyk, 2006). If roads are set developed higher on the slope they will not catch large part of the run-off and if set too low drainage will be more difficult and road floding can occur. Roads facing south will dry up quicker whilst north facing north will take more time. However soils facing north are deeper which facilitates road construction and maintenance work. Depending on different landscapes, drainage and water harvesting techniques vary (see TABLE). 10

14 Roads vs Landscape Construction- Maintenance Drainage characteristics Erosion susceptibility Water Harvesting potential Flatland Low cost construction where materials available and stable soils. In principle more difficult to drain. Depends on soil characteristics. Infiltration structures on waterlogged soils are appropriate. Waterlogging and scouring of road pavements can be a problem. Side drains and embankment stability depend on design standards Borrow pits, rolling dips, cross drainage to infiltration areas, hand dug wells, manually drilled shallow boreholes etc. Mountain- Valley Depending on soil characteristics, north oriented roads normally have deeper soils thus easier to construct and carry out maintenance work Easier to drain at toeslopes with moderate cross slopes (less than 40%) (Zeedyk). Ridge top and valley bottom are harder to drain. Depending on roughness of surface, soil characteristics and slope. Portable soils and steep slopes are prone to trigger erosion issues, especially side drain scouring/gullying Several water harvesting techniques can be applied; spring capture, recharge of borrow pits, water cisterns, side drains leading sheet water flows to nearby fields. Floodplain Elevated subgrades and embankments can increase costs as construction material in floodplains can be scarce. Laminar flows through floodplains require wide drainage systems, flood control mechanisms such as flap gates or surface drainage outlets. Waterlogging on buffer areas between road embankments and floodplain. Flood interception less moisture (sediments) on downstream areas. This can have major impact on flood plain agriculture but also on rangeland conditions, among others because moisture levels affect grassland burning Shallow groundwater hand dug wells and manual drilled boreholes as well as dugout ponds and borrow pits 11

15 Production systems: small holder agriculture, commercial farming, pastoralist systems Different livelihood systems have different water harvesting demands. Small holder/household scale irrigation normally supplement rainfed systems. In case rainfall is scarce or not timely enough, water harvesting from roads could supplement water scarcity periods. Shallow ground water extraction and small storage structures could serve for this purpose. Pastoralist communities seek graze lands to feed their livestock. In this case, water harvesting techniques which spread flows in sheetflow over extended areas would be the preferred option. Commercial farming comes to the expense of high water demands. Medium to large storage of runoff water would be the preferred water harvesting options, namely borrow pits, earth dams and ponds amongst others. Main category of techniques A number of sets of techniques will optimize the use of roads for water, as described below: 1 Combining cross drainage/ side drains with recharge and storage 2 Borrow pits and dugout ponds - beneficial use of excavation material 3 Clever road foundations 4 Spring capture 5 Water spreading weirs/ sand dams combined with river crossings 6 Sand harvesting 7 Protection against erosion from roads 8 Roads as flood control mechanisms 1. Combining cross drainage/ side drains with recharge and storage The purpose of cross drains and side drains is to evacuate water away from road structures. This is often done witohout taken into cosideration water recharge, retention and storage principles. Culverts (under-pavement cross drainage structures) play a mayor role in this regard. The location, size and number of culverts determine drainage patterns and, if done properly, can gear water harvesting from roads. Erosion and siltation issues can be avoided as well. Equally important are side drains and lead-out ditches (also know as mitre drains). 12

16 Collection of water in side drains and later diversion to recharge structures and/or areas is an alternative to take into consideration. Road drain may be routed directly to the land (a practice that is common but not universal) or to soak pits, small reservoirs or ditches or other improved structures (Kubbinga, 2012). The advantage of using such recharge and storage systems along the road drain is that they help accommodate and store peak discharges. When the water is applied to the field directly, moisture storage techniques common in spate irrigation are most appropriate: mulching and deep ploughing in semi-arid areas will ensure the availability of water later in the growing season (van Steenbergen et al., 2010). 2. Borrow pits and dugout ponds - beneficial use of excavation material Borrow pits can be systematically used as recharge, storage or seepage ponds. Borrow pits are excavations done to collect materials - sand, gravel, soil - for road construction and are usually located very near to the road itself. After the road is finished, if not refilled, borrow pits are left unused. However they may be filled with water after rains. The shape and size of the ponds are relevant: round shapes maximize effective storage; deeper ponds have less evaporation loss. Access ramps will facilitate the collection of water. Depending on the soil conditions and geology, borrow pits can also be used as recharge ponds at no additional cost (Nissen-Petersen, 2006). In areas with permanent shallow groundwater borrow pits also serve as dug-out ponds, filled with the water seeping in from the adjacent shallow aquifers. Such ponds have become an important source of water for irrigation or livestock in dry flood plain areas, in Ghana or South Sudan. Excavated material - specifically top fertile soils - can be of compensation owners of land adjacent to roads. Farmers deprived from land due to road construction could benefit from excavated top soils as these can be filled in their farmlands to be used for cropping purposes, see pictures below. 13

17 Figure #: Farmers in Solulta district (Ethiopia) using excavated soil of the road project to reduce waterlogging problems (left) and rock dust crushers along the road producing a rich source of micro-nutrients to farmers (picture at the right). 3, Clever road foundations Road foundations may interfere with the base subsurface flows that feed shallow wells. The road foundation depends on the road type and the traffic it is designed to support. Tarmac roads may have impervious bases 2-5 m thick, but such compacted road foundations are not common for dirt roads. Impermeable subgrades and road foundations can block subsurface flows altering the availability of shallow groundwater and drying up shallow wells on the lower end of the road and increasing water tables on the upper end of the road. Groundwater drainage systems and placement of cross-drains can help revert this situation. Permeable subgrades or lateral drains (water table lowering, e.g. trench drains and California drains), transverse drains in rigid pavements, earthworks drains (e.g. drainage spurs and cut-off drains), and pavement under-drains can be used to control flows entering the road subgrade and foundation (Santinho Faisca et al., 2008). These structures have the primary objective to protect the road from water intrusion in the road structure. However careful placement of these structures allows control of water tables and by-pass road blocking from upstream to the downstream. 4. Spring capture When roads cross hilly areas and the roads are laid in deep cut-slopes of terrain, excavation may open springs in mountain aquifers. These newly opened springs can damage cut slopes and erode land. Drainage masks protect cut slopes from spring flows infiltrating water to the road drainage system. Likewise, protection boxes for newly opened springs collect the spring water and can either be diverted to infiltration structures (such as soakaways) or used directly in surface storage structures, either open ponds or cisterns. It is important to estimate the discharge of these spring flows so as to properly dimension the collection tanks and create spillover structures. The newly opened springs can be used as water supply sources, especially in semi-arid regions. 14

18 5.Water spreading weirs/ sand dams combined with river crossings When dirt roads cross dry river beds or water streams it is common to construct fords (also known as low causeways, drifts or Irish bridges). These road crossings can help retain groundwater upstream of the road crossing and can increase bank infiltration. These structures can have multiple functions. The first obvious one is to allow road traffic to cross the dry river bed. The fords can however also double up as a proxy sand dam, trapping coarse sediment behind them and creating small local aquifers that can store and retain water. Fords combined with roads also have another function, which is to stabilize the river bed of dry ephemeral rivers. Depending on the depth of the river bed, the fords will also slow down subsurface flows and retain groundwater upstream - allowing the development of wells or the construction of infiltration galleries to access the water retained upstream of the ford. This capacity to store and retain shallow groundwater is very relevant in arid regions and improves water access and availability. The golden rules of sand dams apply to such multi-purpose fords as well (Neal, 2012): The road crossing must be build on bedrock or impermeable foundation. Their width should exceed annual flood levels with a safe margin. The height of the spillway on the ford-cum-sand dams must be such that it allows the river to pass over at high discharges and deposit coarse material behind the dam. The road crossing must be built so as not to change the river course, and preferably be placed at a right angle with the river bed. 6. Sand harvesting Harvesting sediment from runoff sediment deposition in road pavement, drainage systems, and downstream fields is a common issue, increasing road maintenance costs. However, when considering structures such as Irish bridges or sand traps, sand can be harvested and used for construction purposes. Governments identifying such places for legal sand harvesting also 15

19 reduce the negative impact of illegal sand mining activities otherwise taking place uncontrolled in more vulnerable parts of the river. Structures as Irish bridges act as artificial sand deposits, collecting sand and sediment in the sand dam (upstream) and sand trap (downstream) (Nissen-Petersen, 2006). It is important that sand harvesters remove the sand from the sand dam in horizontal layers, in order not to disturb the river flow. Similarly, sand traps can be emptied. As these structures can be used as a source of construction material for nearby projects, maintenance costs can partly be earned back. 7.Protection against erosion from roads Protection against water related erosion from roads is major issue. Design of roads drainage systems play a key role in avoiding erosion. Nature of soils, especially sandy to silty soils, which are erosion prone require special attention if roads are going to be laid on them. Other factors such as water pressure build-up within soil/rock mass, slope instability and concentrated flows by road drainage systems ought to be addressed in order to avoid erosion processes such as gullying and road foundation subsidence. A range of techniques can avoid and/or tackle erosion processes. Runoff from the upper catchment and road surface pavement is normally drained through culverts and side-drains. These flows can be chanelled into infiltration systems, namely percolation ponds, check-dams, borrow pits and deep trenches. In this way runoff erosion is avoided and shallow ground water is recharged. In other cases flows spread as sheet flow in surrounding meadows and farmlands are an alternative solution, specially in grazing lands and were spate irrigation and flood farming is practiced. Gully erosion can be treated by regreening with vegetation, heping stabilize gullies and streams. Scour checks are simple and cheap structures meant to prevent scouring and gullying of side drains. 16

20 Scour checks meant to prevent side-drain erosion (source ILO 2008) At a larger scale - erosion mitigation can be implemented through effective watershed management. In this regard several interventions are recommended; priority for upper catchment treatment, early treatment of gullies and minimization of gully heads and rehabilitation of affected areas through simple, cheap, flexible and local available materials are possible solutions. Institutions play a role in the above measures therefore involvement of different stakeholders and governmental offices/bureaus is key for succesful integration of all parties involved. Moreover, inclusion of water harvesting approaches in watershed management and multiple use of roads are additional issues to include at watershed management level. 8.Roads as flood control mechanisms Roads subgrades and embankments act as dikes, many roads in the Netherlands are laid on the top of dikes. In areas prone to periodical floods roads may serve as flood regulators. Roads laid in floodplains often block flood flow fronts diminshing flood areas. However this scenario could be reverted if road design principles are modified. Where suitable (preferably at low and middle laying areas of floodplains) road may be open to flood flows enabling flood corridors including bridges and long culverts, flap gates and fushing sluice gates. Flood control and drainage (FCD) techniques have long been implemented in Asia in countries such as Bangladesh (Wester, & Bron 1998) or Cambodia. Thus roads can act as flood regulators, controlling flood and drainage patterns. Water quality concerns One concern in harvesting water from roads is water quality, in particular the probability of occurrence of grease and oil from traffic. As part of the UPGro Catalyst Research grant, water quality was assessed in northern Ethiopia, along the Frewign/Sinkata-Hawzien-Abreha Weatsbeha highway. Using the gravimeter method water samples were analyzed from dugwells and open ponds situated between meters from the road at four locations. In none of the samples oil/grease was detected. Based on this there is no cause for immediate concern, but vigilance and caution are required, especially in case of surface water bodies. In case road water harvesting is done for groundwater recharge, soil media may act as a filter to many biological and organic substances. 17

21 Scaling up There are two main drivers for upscaling. Firslty the magnitude of road investments (highways and feeder roads) in different parts of the world is large. Road investment remains as one of the top priorities regarding infrastructure development, especially in developing regions. The figures speak for themselves: Sub-Saharan Africa, road investment needs are estimated in 9 billion USD per year although the actual spending is 7 billion (WB, 2010). Asia - investment needs for the period are estimated in 2542,97 billion USD. Per region the estimation is as follows (in billions); for east and south east asia, for south Asia, for central asia and 4.31 for the Pacific (ADBI, 2009). Secondly, alternative planning processes are required. Rural development programmes related to labour and income generation, agriculture, land and water conservation activities should be included as part of rural road construction planning at regional and national levels. Road development is often blind to other activities in areas where it occurs. Cooperation among institutional bodies shall bring multiple use of roads in regional and national agendas. Apart from government bodies, NGOs and the private sector can contribute to developing fluid cooperation and work closely with all stakeholders involved. Following this cooperation, budgets among different bureaus can share additional costs of water harvesting. Best practices and succesful experiences on water hervesting from roads throughout different regions shall serve to develop guidelines for policy makers, practitioners, road engineers and academic professionals. These guidelines shall include not only design principles but also inclusive planning processes, stakeholder engagement and participatory dynamics of road communities in road construction. Conclusions and strategic recommendations This how to do note brings forward a novel approach on water resource management and road development. There are a number of enablers required to make this approach come to a fruitful outcome. Process - As underpinned in this note, integrated processes combining road development and natural resource management is key for successful implementation of water management and road construction as well as a closer and balanced interaction with roads side communites. Capacity building water harvesting from roads is a novel concept, new knowledge and know how is required. Road engineers, agricultural and natural resource management experts, water managers, landscape architects are the target groups. Moreover water harvesting in roads shall be included in university curriculum on colleges covering related fields. New design standards - regarding road construction, design standards with a holistic landscape/watershed approach are needed. Clever combination of surface and ground water 18

22 drainage with water harvesting structures and natural resource management techniques must be included in design principles for rural roads. International funders such as IFAD can pave the way to ensure negative effects of roads are not only reduced but reversed into assets and new design processes and techniques should be incorporated in the road investment programs that they support. Benefits from water harvesting in roads are ample. As shown from several country experiences these are amongst others - erosion issues causing severe damage to roads and landscape can be avoid and/or tackled, water harvesting structures can be used to recharge the shallow ground water increasing water availability, surface water storage through borrow pits and shallow ponds can supply domestic and livestock watering activities, increase in sand mining activities, flood control and flood spreading through embankments/fords/low causeways/water spreading weirs, re-greening of grazing lands, community involvement and labour generation through O & M practices, reduced maintenance costs due to more resilient roads, benefits for local communities making use of water for irrigation and other marketable goods, additional water supply sources through sand dams and spring capturing. Additional resources/tools For more information and related literature refer to the following website; References Briceño-Garmendia, Smits and Foster (2008). De grassi, A. (2005) Transport, poverty and agrarian change in africa: models, mechanisms and new ways forward, IDS Bulletin 36(2): 52 7 < Demenge, J. (2011) Living on the Road, Waiting for the Road: The Political Ecology of Road Construction in Ladakh [online], brighton: institute of development Studies, university of Sussex < [accessed 26 March 2014]. Fairhead, J. (1992). Paths of Authority: Roads, the State and the Market in Eastern Zaire. The European Journal of Development Research (1992) 4, pp ; doi: / Howe, J. (1984) Rural Roads and Poverty Alleviation in Botswana. Rural Roads and Poverty Alleviation. Michigan: Westview Press Kubbinga, b. (2012) Road Runoff Harvesting in the Drylands of Sub-Saharan Africa: Its Potential for Assisting Smallholder Farmers in Coping with Water Scarcity and Climate Change, Based on Case Studies in Eastern Province, Kenya, msc thesis, amsterdam: Vrije university. 19

23 Nissen-Petersen, e. (2006) Water from Roads: A Handbook for Technicians and Farmers on Harvesting Rain Water from Roads, nairobi: asal consultants ltd. Santinho Faısca, J., Baena, J., Baltzer, S., Gajewska, B., Nousiainen, A., Hermansson, A., erlingsson, S., brencic, m. and dawson, a. (2008) control of pavement water and pollution prevention, in a. dawson (ed.), Water in Road Structures: Movement, Drainage and Effects, pp , Nottingham: Springer. Shah, T. (2010). Taming the Anarchy: Groundwater Governance in South Asia. IWMI, Sri Lanka: Colombia Steenbergen et al Guidelines for spate irrigation. Irrigation and Drainage Paper 46. FAO, Rome. Wester, F., Bron, J., 1998 Coping with Water: Water Management in Flood Control and Drainage Systems in Bangladesh. Issue 4 of Liquid gold special reports, International Institute for Land Reclamation and Improvement (ILRI) Wilson, F. (2004) towards a political economy of roads: experiences from Peru, Development and Change 35(3): < 20

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