Application Consultancy Sand Dam Survey and Design in Carracad

Tenders are invited for Application Consultancy Sand Dam Survey and Design in Carracad CONSULTANCY TERMS OF REFERENCE SAND DAM SITE SURVEY AND DESIGN IN CARRACAD BORAMA DISTRICT AWDAL REGION SOMALILAND Project Specifications1 Background Concern Worldwide is a non governmental international humanitarian organization dedicated to the reduction of suffering and working towards the ultimate elimination of extreme poverty in the world s poorest countries Concern engages in long term development work responds to emergencies and seeks to address the root causes of poverty through development education and advocacy work Concern Worldwide is a member of the Building Resilient Communities in Somaliland BRCiS consortium and is currently implementing the DFID funded Somaliland Humanitarian and Resilience Programme SHARP for the period 2018 2022 The programme goal is to enhance the resilience of vulnerable and marginalized communities to recurrent shocks and stresses and engage in sustainable nutritionally sensitive livelihood strategies The BRCiS Consortium s approach to building resilience has been anchored in 5 main pillars 1 BRCiS operates in a collaborative and effective manner identifies innovative programme approaches and ways of working and utilizes learning to improve programme design and implementation2 Vulnerable communities have the capacity to withstand shocks through diversified livelihoods social safety nets and human capital development3 Youth women and vulnerable groups have diversified productive livelihoods protected assets and equitable economic opportunities4 Communities and local stakeholders have the capacity to mitigate the impacts of future shocks through effective management of natural resources community integration into local governance and strong social cohesion5 Population has improved nutritional status through access to WASH health and nutrition services and awareness of good health nutrition and hygiene practicesIn Borama district Awdal region Concern Worldwide and the implementing partner SOSTA engaged with five communities in 2019 to lead a vulnerability and risk analysis and a participatory process to prepare Resilience Community Action Plans The Community Action Plan in Carracad considers enhancing water availability during the dry season through the construction of a second sand storage dam downstream of the current sand storage dam A sand dam is a reinforced concrete or rubble stone masonry structure built across the riverbed of a seasonal river to increase the accumulation of coarse sand upstream and enlarge the natural storage capacity of the riverbed aquifer Sand dams and sub surface dams are increasingly recognised as low cost and robust rainwater harvesting technologies to enhance water availability in drylands and build resilience to the effects of climate change In 2019 Concern Worldwide supported the MSc research study An appraisal of the effectiveness and sustainability of sand dams to improve water security and resilience in rural Somaliland The study captures best practices and lessons learned from practitioners at regional level and appraises the effectiveness sustainability and impact of sand dams on water security and resilience through the study of five communities with access to sand dams and sub surface dams in the regions of Awdal and Woqooyi Galbeed in Somaliland including Carracad This study informs the Concern Worldwide Sand dam pilot project providing preliminary information for the project design Project site information Carracad village 10 4 54 88N 43 4 45 55E has an estimated population of 250 households dispersed in the valley and is located approximately 30km NW from the district capital of Borama district Awdal region Subsistence rain fed farming and sale of goat and camel milk are the main livelihood activities in the community Irrigated farming is marginal The seasonal river at Carracad is located in a narrow mountain valley and is formed of coarse sand deposits on top of a layer of white clay A sand storage dam was built in 2003 and rehabilitated in 2017 It is located in a river section 30m wide just 100 metres from the community centre Google Earth map provided in Annex 1 The dam is made of reinforced concrete covered with a layer of cement It has a total length of 30 8m with a spillway 23 2m long covering the full width of the riverbed The right wing wall extends sufficiently into the rocky steep bank but the left wing does not extend sufficiently on the shallow sandy bank where there is visible signs of water overflow around the wing wall The crest is 78cm wide and exhibits slight erosion with exposure of the reinforcement bars at the central section The height of the visible wall is 1m with approximately 50cmextending to the bedrock and keyed 1m below the bedrock In 2016 the implementing agency repaired the gabions and raised the wall by 20cm but strong flash floods in 2018 partially washed away the gabions At the time of the visit in October 2019 the damaged gabions had not been repaired pictures provided in Annex 2 The sand sample taken at a depth 30cm in the throwback of the dam showed aheterogeneous composition of gravel very coarse and coarse sand medium fine and very fine sand In October 2019 sand was saturated with water at depths of 30m An impermeable while clay layer is located at an approximated depth of 4m There are three communal masonry wells in the throwback of the sand dam with estimated depths varying between 4m and 14m All of them have concrete slabs and a metal cover for manual water lifting The wells have an averagediameter of 3m and are lined with rocks intercalated by 20mm PVC infiltrationpipes Communal well 1 closest to the dam wall is used for domesticpurposes including drinking The well was dug 4m until reaching a white clayimpermeable layer however well 2 has a total depth of 14m and was dugbelow the clay layer 9m into the permeable bedrock Well 2 has a good yieldand is mainly used for livestock watering Well 3 is 9m deep but has loweryield and is occasionally used for livestock and irrigation pictures and wellslocation provided in Annex 2 Carracad is avery scattered community hence the roundtrip to the wells in theriverbed vary from 5 to 90 minutes Additionally part of the population ofsurrounding villages in the valley like Qol Qol and Culacuule also collect waterfrom the sand dam wells in Carracad as this is the closest water source besidestraditional berkads There is no restriction on accessing water from thecommunal wells all community members can access water for free and withoutquantity limitation No groups were identified as excluded in the preliminarystudy The following table summarises the changes perceived by the community afterthe construction of the sand dam in 2003 Dry season water availabilityBefore wells provide water 4 months per year in rainy seasons andimmediately after After wells provide water 9 months per year and dry out during the 3months of Jilal January March Net gain 5 months Water used per day in the dryseasonSignificantly more because more water is available and for a longerperiod In the dry season months the quantity of water used remains very limited Water expenditure in the dryseasonNo fees charged for water before and after the dam Frequency of diarrhealdiseaseLow frequency of diarrhoeas Surface of irrigated land Large increase in the surface of irrigated land upstream of the dams Small decrease in water availability for irrigation downstream Livestock number andconditionLarge increase in number of households from surrounding villages whocollect water from the wells in Carracad dam Many livestock heads were lost with cyclone Sagar in 2018 and numbersare recovering Livestock drinking from Carracad wells are in good healthcondition Livelihoods diversification Home gardening introduced Riverine vegetation More vegetation higher biodiversity upstream of the dam Flood risk Less flooding upstream More flooding downstream as riverbanks expanded Perceived impacts after Carracad dam construction in 2003 Semi structured group interviews inCarracad Concern Worldwide 2019 3 P a g eAccording to community interviews the availability of water in Carracad riverbedincreased from 4 months during rainy seasons and immediately after to 9months April December resulting in a remarkable net gain of 5 months localwater supply Current domestic water use varies from 6 8 jerry cans HH day 23 3 L p d to only 4 jerry cans HH day 13 3 L p d below the minimumSPHERES standard of 15 L p d for drinking cooking and personal hygiene The preliminary study shows the estimated maximum extractable water volume 9 333 m3 in the sand reservoir reached at the end of the rainy season istheoretically sufficient to cover 100 of the domestic water demand for thepopulation of Carracad during the long dry season months estimated at4 500m3 considering 20 L p d and 69 of the combined domestic and livestockdemand Estimated at 13 500m3 However the alluvial aquifer also supplieswater for domestic use and livestock for surrounding villages and demandexceeds supply in the dry season As a result the three wells in Carracad dry upduring the months of January March and the population needs to fetch waterfrom a mountain spring located at 15km CarracadEstimated dam throwback length m 1 000Maximum width riverbed m 35Maximum depth of sand m 4Dam storage capacity m3 46 667Drainable porosity 20 Estimated maximum volume of extractable water from sand deposit m3 9 333Estimated water dema

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