Responsiveness of Ada Sea Defence Project to salt waterintrusion associated with sea level rise

Kenneth O. Mensah & John FitzGibbon

Received: 3 January 2012 /Revised: 12 September 2012 /Accepted: 17 September 2012 /Published online: 2 October 2012# Springer Science+Business Media Dordrecht 2012

Abstract The Ada peninsular in Ghana has suffered rapidcoastal erosion and inundation for over half a century, accom-panied by loss of property and livelihoods, economic stagna-tion and salt water intrusion. Government intervened torespond to these threats by implementing a sea defence proj-ect. A preliminary assessment indicates the project will dealwith some urgent needs of property loss reduction and invig-orate livelihood and economic opportunities. However, it willhave minimal beneficial impacts on groundwater salinization,and may actually intensify salinity of surface water in theVolta River and adjoining water points by shifting salinityintrusion further upstream to affect hitherto salinity-free areas.The spatial reach of the salinity shift is uncertain. The potentialfor further sea level rise will aggravate and accentuate theregion’s water scarcity dilemma if a coherent water manage-ment strategy is not sort sooner. The project demonstrates thelimitations of employing static, narrow objectively designedsea defence project as a response to coastal erosion andinundation, because it lacks the capacity to deal with dyna-mism, complexity and multi-dimensional impacts associatedwith climate change related sea level rise.

Keywords Coastal inundation . Salt water intrusion .

Climate change . Sea level rise . Sea defence . Ghana

Introduction

Historically, several factors lead to salinity levels in waterresources, including over-exploitation of groundwater and

sea level rise (SLR). Studies on the relationship betweenSLR and salt intrusion tend to focus on groundwater (Mellouland Collin 2006; Gornitz 2000). Therefore, there is the need tounderstand salt intrusion in surface water which increasingSLR is likely to intensify. For most coastal areas SLR andstorm surges are important climate change concerns (Kebedeet al. 2010). However, most developing countries are unpre-pared for their impacts, especially regarding water resourcesand supply systems (McGranahan et al. 2007; Nicholls et al.2007). The result is the frequent adoption of ad hoc maladapt-ed responses to these threats.

The Ada area in the Dangme East District (DEDA) ofGhana has been highly susceptible to frequent coastal inun-dation with destructive effects on life, livelihoods and prop-erty. Access to potable water supply remains one of DEDA’sdevelopmental challenges with about 57 % of residentslacking access to potable water (DEDA 2006). Among thecauses of poor water supply is high salinity in coastal areas.Climate change impact on Ada’s water situation pertains toindirect influence on water salinity as a result of SLR andrising tidal waves overtopping unconsolidated low-lyingbeaches and coastal erosion (EPA 2000; Atlantic Rising2009). Consumption of high content of saline water poseshealth problems like heart related diseases. Other waterscarcity related diseases recorded in the district are rashes,bilharzias and cholera.

To forestall the destructive impacts of sea action oncoastal communities in the Ada area the Government ofGhana (GoG), supported by DEDA, proposed the Ada SeaDefence Project (ASDP). Two years later GoG has finallysecured a 68 million Euros loan facility from the BelgianGovernment to undertake the project. The completion of theproject is expected to benefit the region by reducing theperennial risk of coastal inundation Ada residents face andboost the general economic development of the area. How-ever, uncertainty remains about the extent to which ASDPwill alleviate water intrusion problem in the area, especially

K. O. Mensah (*) : J. FitzGibbonRural Studies, School of Environmental Design and RuralDevelopment, University of Guelph,Guelph, Ontario N1G 2W1, Canadae-mail: mensahk@uoguelph.ca

J. FitzGibbone-mail: jfitzgib@uoguelph.ca

J Coast Conserv (2013) 17:75–84DOI 10.1007/s11852-012-0219-y

given increasing SLR forecasts. This paper is a preliminaryassessment of the responsiveness of ASDP to water salinityproblems in the area. The purpose is to highlight the limi-tations of employing static, narrow objectively designedprojects (i.e. ASDP) as a response to coastal erosion andinundation, which are SLR and climate change related, andcharacterized by dynamism, complexity and multi-dimensionalimpacts (FitzGibbon and Mensah 2012).

The context of SLR

Several natural and anthropogenic factors can lead to SLR.Among natural causes are natural accretion which reduceswater reservoirs by supplying sediments to raise the watertable, and coastal erosion which transfers lithological mate-rials downwards or upwards the ocean floor to create a newinland ridge along the coast resulting in SLR (Melloul andCollin 2006; Brunn 1983; Gornitz 1991; Archfield 2003).Anthropogenic factors that contribute to SLR include over-exploitation of underground water, which can cause long-term sinking or rising of continental masses at differentareas; dam construction which reduces river flow and sedi-mentation in delta areas leading to severe coastal erosion,coastline recession and rise in sea level (Melloul and Collin2006); with thermal expansion of ocean water and glaciermelting due to global warming as the most contemporaryconcerns of SLR (Gornitz 1991; IPCC 2001). Gornitz(2000) estimates that growing greenhouse gas emissionshas increased the earth’s average surface temperature byabout 0.7 °C over the past 100 years. With average surfacetemperature predictions between 1.4 and 5.8 °C by 2100(Gordon et al. 2001) average ocean surface temperatures arelikely to increase significantly.

According to Zhang et al. (2004) SLR is not a directcause of beach and coastal erosion but a catalyst that influ-ence waves to act further up the beach and larger waves toreach the coast. Melloul and Collin (2006) noted that “risingocean levels will enhance processes already on-goingthroughout the world, which include submergence of largeportions of shallow relief areas in estuarine and deltaicareas”. This has negative repercussions for salt intrusioninto water resources. Thus, there is a great need to developmitigation and adaptive capacities to ameliorate thesethreats in coastal areas.

Ghana’s Environmental Protection Agency (EPA) pre-dicts that a SLR of 1.0 m by 2100 in coastal areas couldinundate 1,120 km2, accounting for two thirds of total landarea and will put 132, 000 people living within the EastCoast at risk. It will cost an estimated US$1.14 billion toprotect all shorelines at risk with populations greater than 10persons per km2 with seawalls, and US$590 million toprotect only the “important areas” (EPA 2000). A 30 year

shoreline analysis indicates that the entire 550 km coastlineof Ghana is experiencing relative high rates of erosion—0.35 m/year, 0.92 m/year and 1.28 m/year in the west, midsection and east coasts respectively (Wiafe 2010). Half thetime wave height measures about 1.4 m with about 10 to15 s periods (Appeaning et al. 2008).

Rapid erosion in the east coast is partly due to post-construction effect of the Akosombo Dam upstream the VoltaRiver which has reduced flow discharges and/or flow veloc-ities. The result is reduction in sedimentation on either side ofthe river mouth, increasing delta erosion and shoreline reces-sion to allow waves to act further up the beach and largerwaves to reach the coast (Ly 1980; Alkyon 1998; Wellens-Mensah et al. 2002). The Volta Dam is estimated to havereduced fluvial sediment supply of the Volta River from about71 million m3/year to 7 million m3/year (Boateng 2009). Thisis consistent with the general view that dam constructionsreduce sedimentation and lead to increased erosion, causingfurther recession of the seashore and rising sea levels. Theresultant erosion could lead to further seawater intrusion thatcan damage coastal water resources and valued ecosystems,with related consequences on property, infrastructure andlivelihood losses (Melloul and Collin 2006).

Methodology

The approach is part of a broader project linking precautionwith adaptive co-management to adjust water points ofAfrican rural coastal communities to climate change fundedby the International Development Research Council. Aqualitative analytical approach was adopted, involving tri-angulating field data with secondary source data. Primarydata comprised interviews with key informants from 18stakeholder institutions including government, research,university and civil society agencies. Also, informationwas gathered from three affected communities (Totope,Azizanya and Alorkpem) using focus group discussions,interviews with elected members, opinion leaders andhouseholds. Community participants were restricted to per-sons age 40 and up, on the assumption that younger peoplewould have less experience of climate change and fewerrelevant observations (van der Geest 2004; Gyampoh et al.2009). Participants responded to questions grouped underfour clusters: perceptions of causes of and relationshipsamong coastal erosion, inundation and climate change; con-sequences on communities, especially salinity of drinkingwater resources; adaptation strategies and; perceptions of theefficacy of ASDP. The primary data was then triangulatedwith secondary sources including official government reports,technical and impact assessment reports, published researchmaterials and media reports on the subject. This permitted

76 K.O. Mensah, J. FitzGibbon

carrying out a qualitative analysis, seeking consistency anddiversity in the major themes of the two data sets.

Study area

I. Locational characteristicsThe Ada area falls within DEDA of the Greater Accra

Region. The area is described as a peninsular because itis almost surrounded by water; the Atlantic Ocean to thesouth, Volta River to the north and east and, Songorlagoon to the west (Fig. 1). Most of the coastal commu-nities in the region are located either on or behind theouter sand barrier close to the Volta Estuary and sepa-rated from the sea by a narrow strip of sand bars mea-suring about 30–40 m wide and 3–4 m above the meanwater level (Ly 1980; Ecorem 2010). The sand barrier iscommonly overtopped by storm surges which results infrequent inundation of low lying coastal communities.The stretch of coastal villages from the Volta estuary toSongor Lagoon has a significant number of houses over-run by the sea. Residents of Azizanya and Totope esti-mate that their original villages destroyed by the seawere about 5 km in the sea (Personal Communications,

May 2011). Currently, the village of Kpodzi and theoffices of DEDA are being relocated because of thethreat of sea advance.

The Ada area has a long history of coastal inundationwhich is attributed largely to over half a century of seaerosion. Erosion figures for the area vary. The Ada FoahWildlife Division responsible for beach profiling in thedistrict record 6 m annual rate of coastal recession. Theformer Ministry of Housing, now Water Resources,Works and Housing (MWRWH) estimate about 10 mper year (Ministry of Housing 2004). Natural and humanfactors contribute to coastal erosion in the region. Themain natural factor is the historical cycle of shifts of theVolta River mouth which has resulted in gradation pro-cesses of Ada beaches over many decades (Ly 1980;Alkyon 1998). Prior to the construction of Akosombodam, the Volta River flowed with greater intensity trans-porting heavy load of fluvial sediments deposited at themouth to create an extensive submarine sand barrier.This submarine eb-tidal delta in front of the river mouthblocked the normal eastward movement of longshorecurrent laded with sand, resulting in local beach accre-tion at Ada. Over time however, this delta eroded lead-ing to erosion of the beaches. The impact assessment

Fig. 1 Map showing regional area of study (modified Google Maps)

Responsiveness of Ada Sea Defence Project to salt water intrusion 77

report (IAR) of the ASDP pointed to this process along-side human factors like the construction of AkosomboDam and mangrove deforestation as responsible for thecurrent trends of coastal erosion in the area. In addition,studies have pointed to the links of the “breakwaters” ofTema Harbour and interference with the eastward direc-tion of littoral transport further reducing littoral sand sup-ply (NADMO 2007). Others, including NGOs (CAREInternational) and community based organizations(CSOs) have pointed to links between coastal inundationat Ada and climate change, especially SLR (GNA 2010).

II. SLR and Water Salinity in AdaUntil recently water supply in DEDAwas among the

worst in the Greater Accra Region. The South EasternDistrict Water Supply Project (SEDWSP) at Kesevesponsored by the Department of International Develop-ment (DFID) and GoG and managed by Ghana WaterCompany (GWC), was the only source of potable waterwhich served 37 % of residents, mainly in urban areas.Consequently, prior to the construction of Three DistrictsWater Supply Project (3DWSP) at Aveyime in 2008,57 % of mainly rural residents lacked access to potablewater and depended on raw water from unprotected sour-ces such as rivers, streams, wells, dugouts and tankers(DEDA 2006). Currently, about 129 communities inDEDA are reportedly connected to the 3DWSP system(Private Systems Operator, Personal Communications2011) raising the district access rate to an estimated75 % (District Planning Officer, Personal Communica-tions 2010). Despite the improvements in DEDA’s watersupply some communities still face dire water needs withthreats of water borne diseases due to the communities’inability to afford potable water or the absence of pipedwater thereby perpetuating pre-existing problems wherehumans and livestock co-share the same water sources(Rao and Agyeman 2010).

Salinity conditions complicate inadequate supply ofpotable water in the district, especially for areas in prox-imity of the coastline (DEDA 2006). Saline contaminatedwater sources include treated water, boreholes, well andsurface water (Appiah 2010). An estimated 2.7 % of Adaadults suffer from chronic heart related diseases, partlyattributed to high salt water intake (GNA 2007; AtlanticRising 2009). The entire Ghana coast is expected toexperience 1.0 m SLR by 2100 (EPA 2000), with highervulnerability for the east coast, including Ada (Wiafe2010; Ly 1980; Alkyon 1998). Thus SLR is at least acatalyst in the rapid erosion of beaches and frequentbeach overtopping by storm surges which result in inun-dation and eventual salinization of underground waterresources in Ada (Ecorem 2010). This makes many un-derground water sources at the Ada coast unwholesomefor drinking purposes.

Regarding surface water, the Volta River specificallyand some of its tributaries record high salinity levels dueto direct inflow of sea water during spring tide. In 2005the Keseve water plant on River Angaw, a tributary of thelower Volta gained national attention for extensive saltintrusion in its water supply which management of GWCattributed to spring tide. But Azizanya residents reportthat salinity levels of Keseve water corresponds to regularoceanic (high–low) tidal cycle. Consequently, communi-ties that access Keseve water for domestic uses requestrelocating the plant to a less salinity concentrated area orbe reconnected to 3DWSP (Appiah 2010). Wells andboreholes adjoining the Volta River also suffer salinityrelated problems due to underground seepage from theriver.

Description and scope of ASDP

In 2009, a 68-million euro investment was defined by gov-ernment for the construction of a sea defence wall at Ada toremedy once and for all, the perennial problems of floodingfrom the sea which threatens lives, property and vocationsof the people of Ada (Daily Graphic 2009). After 2 years ofpessimism about the project among many residents andDEDA officials, in March 2011 the project began withDredging International putting up offices at Kpodzi.

The primary goal of ASDP is to provide a 14 km longstructural solution for the coastal protection of the beachbetween Songor Lagoon and the Volta estuary (Fig. 2) (Bollenet al. 2010). The project is under the auspices of MWRWH.Design of the project is awarded to International MarineDredging Consultants with Dredging International ServicesCyprus Ltd. as the executing contractor of the project (Ecorem2010). The specific objectives of ASDP are to tackle:

& Coastal erosion problems and damage to structures andproperty;

& Regular overtopping, flooding and subsequent saliniza-tion of some coastal areas;

& Salinization of groundwater at Ada village;& Closure of the Volta River mouth;& Increase in Bilharzia occurrence.

The project is divided in three phases:

Urgent Phase: The provision of 6 groynes and a longgroyne system west of Volta River and sand beachnourishment between the groynes, where coastal ero-sion rates are highest. Coverage area is approximately4.7 km ending near Otrokpe village. The groynes areintended to trap longshore littoral drift over approxi-mately 4.5 km distance.Medium Phase: Involves the creation of a permanentopening to the Volta estuary by removing sand bar

78 K.O. Mensah, J. FitzGibbon

formation across the estuary; installation of a longgroyne on the eastern side of the river to protect theopening. The idea is intended (i) to overcome recurrentsiltation problems and (ii) to create a suitable and per-manent entrance for the fishing community of Azizanyaas well as increasing the tidal flow of marine water inthe Volta estuary.Long Term Phase: Involves the provision of groynesand beach nourishment for the remainder of the projectarea; and improvement in road networks to Ada Foah.

Potential impacts on water resources and supply

The project has the potential to achieve its major objectiveof reducing coastal erosion and inundation, with a goodchance to ameliorate property and livelihood losses andrevamp economic development. The main water supplyconcern is salt intrusion in both groundwater aquifers dueto storm surges overtopping beaches and direct sea flow intosurface water, raising salinity and associated flocculationlevels. These may be associated with SLR. Other water

resource concern is Bilharzia eradication since the diseasehampers economic and recreational activities at the Voltaestuary. Thus the main areas of potential beneficial impactsof the project on water supply are:

i. General development: ASDP has the potential to preventfurther coastal erosion and inundation (Bollen et al. 2010).This will minimize public health concerns while creatingpositive ripple effect on local social and economic develop-ment e.g. fishing, tourism and investment. For instance, theremoval of sand bar formation across the estuary to allowconstant sea flow into the Volta during phase II of theproject is anticipated to maintain a constant salinity levelat the estuary, which could possibly resolve Bilharzia issuesin the estuary and increase tourism activities.ii. Overtopping and flood reduction: This may be the majorbenefit of the project on water supply for many residents ofthe area who rely on groundwater supplies. It is anticipatedthat beach nourishment will strengthen sand barrier and, inturn, decrease coastal inundation from overtopping events.This will indirectly lead to improvement in groundwaterquality although it depends on community location, withhinterland communities as the biggest beneficiaries.

Fig. 2 Phasing of coastal protection works at Ada

Responsiveness of Ada Sea Defence Project to salt water intrusion 79

iii. Climate change: A possible resolution of long termglobal warming issues may be achieved as an indirect ben-efit. Indirect benefit because climate change is not an ob-jective to be addressed by the project, since it is consideredto have no causal link to the problem. But it is considered apotential benefit of the project because of the possibility tominimize SLR related coastal erosion and inundation andassociated salinity consequences.

Conversely, the project has major negative consequenceson water resources. Even though the IAR downplays antic-ipated negative impacts of regular large scale constructionissues and impacts on specific parts of ecosystems as miti-gable, with regards to the relationship among climatechange, SLR, freshwater supplies and the project the IARraised pending concerns:

“Possible scenarios regarding the efficiency of the proj-ect in reducing coastal erosion and overtopping events,should take global climate change into account. Follow-ing global warming, mean sea levels are expected torise…Obviously this will put low-lying areas in theRSA (Regional Study Area) at risk of flooding on thelong term, causing salt water intrusion and compromis-ing fresh water supply in the area. The project, throughbeach nourishment, likely addresses this issue to someextent for the Local Study Area (LSA). Some hinterlandareas could be flooded from the estuary however, andthe beach nourishment will have limited beneficial im-pact on that” (Ecorem 2010).

It is puzzling that anticipated climate change relatedbenefits and challenges of the project with regards to watersupplies are noted by the IAR when the same report con-spicuously omitted climate change and SLR as insignificantcausal factors of coastal erosion and inundation in Ada.Equally perplexing is that despite the IAR warning thatpotential SLR could have a long term negative impacts onsalinity levels in freshwater supplies, including surface wa-ter of the Volta River, which is likely to be exacerbated bythe inefficacy of the sea wall to mitigate, it was convenientlyomitted as unimportant objective to be addressed by theproject.

In an interview with a MWRWH’s official regarding theimpacts of climate change, specifically SLR, on sea erosionand salt water intrusion into the Volta River, the answer was:

“Sea erosion is a problem in the Ada area. However,salt water intrusion is primarily an underground waterissue, not surface water problem. The dynamics of saltintrusion involves communication between the oceanand freshwater systems. A distinction needs to bemade between natural tidal cycles and SLR which isa direct result of climate change. For SLR to become aproblem the sea has to rise above the ground-level and

above the water table. The likeliest scenario for this tooccur is during flooding. Currently, SLR in Ghana isminimal. It is therefore an insignificant variable inconsiderations of the construction of sea defence inAda. Tidal variation (high and low tide) increases theinteraction and flow in either direction. During hightide the sea flows into the Volta River, with salt waterreaching a little further inland. If this gets close tonearby intake points of water treatment plants, thensalt intrusion occurs. But, this is not a common occur-rence. The story is quite different for undergroundwater because salt intrusion will or will not occuranyway depending on whether a given communitywater point is supplied by an “open” or “closed”aquifer” (Personal Communications, November2010).

The Ministry’s position espoused by the official iscounter-intuitive against the backdrop of coastal studies,IAR and local experiences in the study area specifically,and the country generally, which suggest linkages betweenSLR, coastal erosion, coastal inundation and potential watersalinity (Appeaning et al. 2011; Wiafe 2010; GNA 2007;Boateng 2009). It seems the interaction between SLR, along term effect of climate change, and beach erosion, tidalinundation and salt intrusion into freshwater is not fullygrasped or is underplayed by the ministry and projectdesigners. It is common knowledge that SLR influence tidalaction such as the frequency, intensity and spatial reachaffecting water points hitherto removed from sea influence(Gornitz 2000). As Melloul and Collin (2006) pointed out“the question is not whether sea levels will rise, but ratherhow a change in sea level might alter the profile of coasts asregards coastal lithology, the integrity of coastal groundwa-ter resources, and the ecology of the coastal environment”.In this regard, “particular attention should be paid to coastalareas with low relief, where high waves could lead tosignificant inland damage”.

The EPA, Ghana’s leading authority on climate changeand environment predicts a 1 m SLR by 2100 with expecteddevastating socio-ecological effects on coastal communitiesespecially in the east coast due to the combined effects oflow coastal elevations and rapid rates of erosion (EPA2000). If the sea were to rise as projected, low-lying coastalwetlands and dryland areas could be severely affected bydirect inundation and erosion of soft shores. Boateng (2009)demonstrates that the entire Volta delta area is susceptible toerosion and inundation as a result of SLR, and that theregion could be submerged by 1 m SLR, whereas a 2 mSLR may result in inundation with some flood watersextending up to 15 km inland. Worrying effects includesalinity intensification in estuaries and aquifers, raisedcoastal water tables, increased coastal flooding and storm

80 K.O. Mensah, J. FitzGibbon

damage to beach facilities (EPA 2000, 2005; Douglas et al.2008). These concerns may be aggravated by a likely in-crease in the flow velocities of sea water in the artificialopening. Even the IAR underscored that a permanent open-ing of the Volta Estuary could expect a long term negativeimpact on water quality with likely significant impact on thephysic-chemical water characteristics of the estuary:

“The most significant change will be an increasedsalinity in this zone, whereby the salinity gradient willshift to the north… The intrusion of salt water furtherinto the estuary will probably lead to local changes inwater quality. In places where the fresh water is highin particulate organic matter content comes in contactwith salty coastal water, the organic matter starts toflocculate creating depositions of dark material inwhich toxins and nutrients tend to accumulate. Thiscompromise the quality of water in the far southernpart of the estuary, even more so because it createsnutrient-rich conditions in which many bacterialand viral organisms, capable of causing diseasesthrive. Hence, by opening up the estuary, this zonecould be drawn into the estuary, negatively affect-ing water quality. However, the spatial extent ofthe salinity shift is uncertain, and rated low tomoderate compared to some natural phases in theestuary dynamics where openings have been creat-ed naturally that are far larger than the plannedaccess channel” (Ecorem 2010).

The comparison between natural and planned channelsizes is largely correct. But the telling truth lies in what isleft unsaid in the comparison. Natural openings are usuallytemporary, lasting few months. On the contrary, the plannedopening will result in a steady and permanent flow of the seainto the river. That means there will be constant salt intru-sion instead of the occasional intrusion associated withnatural cutting. The completion of the project will intensifysalinity and flocculation problems due to the cumulativesteady salt water flow into the river over a long duration,which anticipated SLR over time is likely to accelerate.

Thus there is little doubt that SLR impinge on waterquality in Ada area and the construction of the ASDP willaccentuate salinity problems in water supply. Five interre-lated indicators denote the nature of the salinity impacts ofthe project—intensity, duration, steadiness (frequency), are-al expanse and reversibility with associated implications forpublic health (Table 1). The impacts will however be differ-entiated based on community location and type of watersources (Table 2). The two piped water systems are inKeseve and Aveyime. The Keseve treatment plant is within10 km distance from the coast and known to record highsalinity conditions during spring tide when storm surges areable to push salt water upstream to the intake point on

Angaw River (GNA 2007). Azizanya respondents who ac-cess their piped water supply from Keseve confirmed therelationship between saline taste of the water and springtides. They further maintained that salinity conditions ofKeseve water corresponds to regular high–low tidal cycles,and deteriorates only during spring tide. Consequently,many residents resort to raw water from the Volta Riverarguing that it is nonsensical to pay for piped water whichis equally saline as the river. No wonder consumption ofKeseve water is implicated in the incidence of highheart-related diseases in Ada area (GNA 2007). ButGWC management insists salinity conditions are withinWHO standards except for the odd spring tides (Person-al Communications, May 2011). The creation of thedam may have reduced saline water penetration fromabout 30 km to 10 km from the sea in some areas(Pople and Rogoyska 1967) but Keseve plant is withinthe new radius. This suggests that estimated mixingtime of River Angaw and the ocean water may beshortening and likely to worsen under the project’sintended regime of steady sea flow into the Volta.

It is uncertain at this point whether salt intrusion couldeventually reach the intake point of the 3DWSP at Aveyime.Given the distance, it is improbable. This means piped watersupply to Totope is unlikely to be affected, if the villagewith its pipe stands survive the sea attacks until the com-pletion of ASDP estimated in 2014. Totope is expected to becovered during the final project phase.

Similarly, salinity levels in ground water sources mayreduce or increase depending on location. Hinterland com-munities may be the biggest beneficiaries of reduced salinitybecause of possible decrease in the number of coastal inun-dation. Also, coastal communities like Totope may benefitfrom traditional “hand dug hollows”. These are temporaryshallow holes 0.3–0.6 m deep created at the beach duringlow tide with strong waves which break further offshorefrom the beach. Freshwater being less dense, sits atop thedenser salt water allowing villagers to carefully collect whiletasting for salt. But similar benefits may not accrue tocommunities such as Aminapa and Media with adjoiningwells to the Songhor lagoon because of the high salinityconditions of the lagoon.

However, communities which depend directly on rawwater from the Volta River will confront the greatest dilem-ma. Although the exact spatial extent is uncertain, islandcommunities like Alorkpem, Aflive, as far as Pediatorkopecould expect higher salinity and flocculation levels becauseof expected upstream salinity shift. Already Alorkpem res-idents have abandoned their protected borehole for rawwater from the Volta River because the borehole water tastessoapy/muddy and rapidly changes to a reddish black colourafter sitting for a short period—an indication of chemicalreaction (flocculation).

Responsiveness of Ada Sea Defence Project to salt water intrusion 81

Mitigation

According to the IAR the main goal of mitigation measuresis to adapt the design of the project to enhance positiveeffects in order to compensate for negative impacts, to thegeneral benefit of the project and its beneficiaries. In thisregard, mitigation is the obvious strategic choice whenprevention is considered untenable against negative impacts.The project’s main adaptation is expected to be:

& the preservation of (part of) the sand spit, which plays amajor role for the sea turtle in the area, and the creationof suitable nesting beaches;

& address the most critical areas with respect to the directloss of property.

These mitigation areas, especially with regards to prop-erty loss reduction is well reasoned because our findingsshowed that coastal inundation is the major coastal hazardand the most urgent concern of affected communities. Allrespondents in Azizanya and Totope believe their wellbeinghas been negatively impacted by coastal inundation. Alork-pem residents were divided on whether coastal inundationdirectly affects their water supply but were nearly unani-mous in their belief that the severity of flooding on theisland is a result of increasing storm surges and risingSLR. This supports studies in other coastal areas of theregion (Appeaning et al. 2011; Oteng-Ababio et al. 2011).

Nevertheless, the deafening silence on mitigation strate-gies for water resources in spite of indications of probablelong term negative and irreversible impacts of the project onwater quality is worrying. Such silence is an ambivalent

strategy; it is neither an admission nor denial of the possibleimmitigable impacts of the project on water supplies. Ad-mitting such impacts will place culpability on implementersfor negligence. But non-expression of the problem is notsynonymous to the absence of the problem. Therefore it is away to circumvent culpability for not taking precautionarymeasures when necessary. Consequently, implementersof ASDP have no strategic plans to assist communitiesto adapt to impending heightened salinity challenges.Neither DEDA nor communities have any contingencyaction plans to cope with the project’s impacts on theirwater sources such as finding alternative water sourcesor providing education on efficient and hygienic wateruse practices.

Given that the project is already underway and the gen-eral poverty in the district, mitigation options for watersupply are limited. Water importation is perhaps the mostpractical option. The DA must negotiate to expand watersupply system to affected communities. However, since theASDP is likely to increase salinity levels in the Kesevetreatment plant, the plant must either be relocated furtherupstream or probably offload its client communities unto the3 Districts scheme. In addition, tanker services may be re-introduced, but only on the premise that quality standardscan be set and enforced. Unfortunately, Alorkpem and otherisland communities will suffer collateral damage since theirlocation makes it unlikely to be reached by any of thesemitigation interventions. Well and borehole options must berevisited but they must be well researched before drilling toensure aquifers will yield drinkable, not saline or flocculatedwater as in the case of Alorkpem.

Table 1 Project impact on water supply (modified from Ecorem Impact Assessment Report 2010)

Impact description Direction Intensity Geographicextent

Duration Reversibility Frequency

Number of overtoppings Positive Decrease local Long Irreversible High

Salinity Negative Increase? Local Long Irreversible High

Flocculation Negative Increase? Local Long Irreversible High

Indirect groundwater qualityimprovement

Depends onlocation

Depends onlocation

Local Long – –

– impact considered less relevant

? magnitude unknown or certain

Table 2 Salinity risk and miti-gation based on type of watersource and location

IP improbable

? magnitude unknown or uncertain

Source Water supply system Groundwater Surface water MitigationLocation

Mainland

Far from estuary IP i.e. 3DWSP Low? Low? Easy

Close to estuary High i.e. Keseve High-moderate High-moderate Difficult

Island Not served High High-moderate Difficult

82 K.O. Mensah, J. FitzGibbon

Lessons for future

The major lesson from ASDP relates to management anddesign for complexity. ASDP demonstrates the limitationsof using a narrow objectively designed sea defence projectwhich lacks the capacity to address multi-level and multi-dimensional issues. The result is excluding some crucialissues like water salinization unmanaged. Coastal erosionand inundation are signs of SLR and climate change. Andclimate change is a quintessential wicked problem for Gha-na’s water sector: a dynamic, complex and multifacetedproblem with intransigent interconnected challenges for wa-ter resources and management institutions (FitzGibbon andMensah 2012). In this case SLR issues are further compli-cated by the construction of Akosombo Dam and TemaHarbour which has altered natural coastal processes at Ada.

What is needed to manage water salinity and otherneglected issues by the project is a more functional coastalmanagement project that focuses on a systemic approach.An integrated coastal management project which recognizesmulti-level linkages among social and ecological processes,the distribution of impacts and capacities among stakehold-ers is a better functional design.

Conclusions

The study showed that the ASDP will decrease coastalerosion and inundation associated with storm surges andcreate a safe landing area for fishermen. On that basis theproject will be responsive to protecting lives, property andlivelihoods especially among local fishing communities. Inaddition, the permanent opening of the estuary to the oceanto eradicate bilharzia and improve recreational and tourismactivities at the estuary seems like a step in the right direc-tion. These major objectives of the project intersect with theurgent needs of affected communities. There is a high prob-ability that they will be achieved, in which case the projectmay be said to be responsive. Similarly, the project will havesome benefits on underground water supplies mainly inhinterland communities removed from large water bodiesin direct communication with the sea such as the Volta Riverand Songor Lagoon.

However, the study shows that “hard” engineering seadefence while beneficial for beachfront protection is not anelixir for all coastal problems as it creates its own set ofecological externalities for coastal zones. In Ada’s case,there are indications of long term negative impacts on fresh-water sources as a result of the engineered increased flow ofsea water into the estuary. This has a high potential tointensify salinity over a longer duration and areal extentwith a significant chance the effects will be irreversible.Salinity and flocculation in the Volta River and tributaries

close to the estuary as well as underground water of neigh-bouring communities will be affected. But, this will bemediated by access to different water sources and proximityto the estuary with increasing vulnerabilities for all watersources in close proximity. Keseve water supply systemwhich serves Azizanya, boreholes and wells of Alorkpemand other islands communities in close proximity to theestuary will be affected. The added worry is that the exactmagnitude and areal extent of these impacts are uncertain.

This situation is largely a demonstration of the limitationsof using a single or narrow objective designed sea defenceproject which lacks the capacity to address multi-levelissues, leaving out some crucial issues unmanaged. Coastalerosion and inundation are signs of SLR related to climatechange. And climate change presents an intractable dilemmafor water management in Ghana. The exclusion of SLR asinsignificant influence on coastal inundation in the assess-ment, design and implementation of the ASDP interventionis a fundamental error which lacks understanding of thenature of the problem. Neither government nor InternationalMarine Dredging Consultants and Dredging InternationalServices Cyprus Ltd. have any expressed simulations orstudies planned to assess the influence of SLR on the proj-ect. Given the centrality of SLR to global discussions oncoastal recession, submergence and salt intrusion in coastalcommunities (IPCC 2007), it is baffling that SLR was gliblydiscarded as pedestrian to the design and implementation ofASDP, even against the allusion of IAR to its potential longterm negative effects of the project. Moreover, lack ofmitigation efforts against the project impacts on waterresources without local capacity building to adapt toimpending salinity vulnerabilities is counterproductive.

From a planning and policy perspective, problem identifi-cation is crucial because it sets the context within whichintervention design and implementation policies are shaped.Thus excluding SLR from the final design of the project is notsurprising because of the failure to acknowledge its impactsfrom the outset. However, because of the uncertainties in-volved in estimating the impacts of ASDP as well as in SLRforecasts, the exclusion prohibits the application of the pre-cautionary principle as a reasonable preventative initiative(Ecorem 2010). The little premium the project puts on climatechange, SLR and salt intrusion undercuts the country’s inte-grated water management orientation (MWRWH 2006), andby extrapolation implicates government and DEDA for theirnon-commitment to coastal water resource management andsupply. But every scenario indicates that a systemic coastalmanagement and integrated water management approachesare needed for Ada and the whole Volta-delta.

Acknowledgment Funding for this project was provided by theInternational Development Research Center (IDRC).

Responsiveness of Ada Sea Defence Project to salt water intrusion 83

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