American Journal of Civil Engineering and Architecture
ISSN (Print): 2328-398X ISSN (Online): 2328-3998 Website: Editor-in-chief: Dr. Mohammad Arif Kamal
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American Journal of Civil Engineering and Architecture. 2015, 3(3), 86-100
DOI: 10.12691/ajcea-3-3-5
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Modelling Rainwater System Harvesting in Ibadan, Nigeria: Application to a Residential Apartment

Omolara Lade1, and David Oloke2

1Department of Civil Engineering, University of Ibadan, Nigeria

2Faculty of Science and Engineering, University of Wolverhampton, United Kingdom

Pub. Date: July 23, 2015

Cite this paper:
Omolara Lade and David Oloke. Modelling Rainwater System Harvesting in Ibadan, Nigeria: Application to a Residential Apartment. American Journal of Civil Engineering and Architecture. 2015; 3(3):86-100. doi: 10.12691/ajcea-3-3-5


Reduction of water consumption associated water wastage in the residential sector is a rapid pressing issue. The residential sector is a substantial consumer of water in every country and therefore constitutes a focus of water consumption efforts. Since the water consumption, characteristics of the residential sector are complex and inter-related, comprehensive models are needed to assess the technical and economic impacts of adopting rainwater harvesting (RWH) as a sustainable system suitable for residential applications in developing countries. This paper has presented the hydraulic and financial modelling of a RWH system using a residential apartment in Ibadan, Nigeria. With a RWHS being site-specific, a Raincycle model was used to optimise tank size and savings. Sensitivity analysis and MonteCarlo simulation were also carried out. The analysis consists of a detailed assessment of the proposed system, taking into account 18 parameters. Seven of these are fixed parameters- catchment surface area, first-flush volume, storage tank volume, pump power rating, pump capacity, UV unit power rating and UV unit operating time while 11 are variable parameters- rainfall profiles, runoff coefficients, filter coefficients, additional inputs (if any), discount rate, electricity cost, mains water cost, water demand, disposal cost, capital cost and decommissioning cost. The RWH and water savings efficiency were assessed and payback period was estimated. Optimising tank size results reveals that the maximum percentage of demand that could be met was 70.6% with a tank size of 4 m3. Optimising saving analysis showed that there were four tank sizes with a potential long-term profit. The best was 4 m3 tank which was predicted to save $259 over 50 years and had a payback period of 21 years, which is typical for a current domestic system. The results show that significant reductions in the total fresh water consumption and the total cost can be obtained. A Monte Carlo simulation shows an important influence of a given set of conditions on the economic viability of RWH systems.

rainwater harvesting water savings payback period residential apartment Ibadan Nigeria

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[1]  UN, Water for People, Water for Life: UN World Water Development Report (WWDR), UNESCO and Berghahn Books, UN 2003.
[2]  WHO, Water, sanitation and hygiene links to health, facts and figures WHO, updated November 2004. Online: [accessed 16 July 2015].
[3]  UNEP, Rainwater harvesting and utilisation-an environmentally sound approach for sustainable urban water management: an introductory guide for decision makers, United Nations: Division of Technology, Industry and Economics, United Nations Environment Programme (UNEP) 2002.
[4]  UN-HABITAT, Rainwater harvesting and utilisation. BlueDrops series (3 books). Nairobi Kenya: United Nations Habitat Programme 2005
[5]  White, S., Turner, A., Fane, S., Giurco, D. Urban water supply- demand planning: a worked example. In: 4th IWA Specialist Conference on Efficient Use and Management of Urban Water Supply; 2007
[6]  Orebiyi, E.O., Awomeso, J.A., Idowu, O.A., Martins, O., Oguntoke, O. and Taiwo, A.M. Assessment of pollution hazards of shallow well water in Abeokuta and environs, southwest, Nigeria. American Journal of Environmental Sciences 6(1), 50-56, 2010.
[7]  Oweis, T. and Hachum, A. Water harvesting and supplemental irrigation for improved water productivity of dry farming systems in West Asia and North Africa. Water Management 80, 57-73, 2006.
[8]  Frot, E., van Wesemael, B., Benet, A.S., House, M.A. Water harvesting potential as a function of hill slope characteristics: A case study from the Sierra de Gator (Almeria Province, South-East Spain). Journal of Arid Environment 72, 1213-1231. 2008.
[9]  Fewkes, A. The Technology, Design and Utility of Rainwater Catchment Systems. In: Butler, D. and Memon, F.A. (Eds). Water Demand Management. IWA Publishing. London, 2006.
[10]  Hermann, T. Schmida, U. Rainwater utilisation in Germany: efficiency, dimensioning, hydraulic and environmental aspects. Urban Water, 1 (4), 307-316, 1999.
[11]  CWWA, Report on rainwater harvesting and grey-water reuse for potable and non-potable uses. Report to Canada Mortgage and Housing Corporation, Ottawa, ON, Canada: Canadian Water and Wastewater Association (CWWA); 2002.
[12]  de Gouvello, B. Derrien, F., Khouil, Y. The French experience in rainwater reuse in commercial buildings. Plumb Syst Des March/April: 12-17, 2005.
[13]  Kloss, C. Managing wet weather with green infrastructure: municipal handbook-rainwater harvesting policies. EPA-833-F-08-010; Online: 2008.
[14]  Schets, F.M., Italiaander, R., van den Berg HHJL, de Roda Husman, A.M. Rainwater harvesting: quality assessment and utilization in the Netherlands. Journal of Water Health, 8(2), 224-235, 2010.
[15]  Golay, F. Rainwater harvesting in urban New Zealand [M.Sc. thesis]. Lausanne, Switzerland: Ecole Polytechnique Federale de Lausanne/Massey University, 2011.
[16]  MPMSAA. Rainwater tank design and installation handbook. Australia: Australian Rainwater Industry Development Association, Master Plumbers and Mechanical Services Association of Australia (MPMSAA); 2008.
[17]  TRCA. Performance evaluation of rainwater harvesting systems. Toronto, ON, Canada: Sustainable Technologies Evaluation Program (STEP). Toronto and Region Conservation Authority (TRCA); 2010.
[18]  Meera, V. Ahammed, M.M. Water quality of rooftop rainwater harvesting systems: a review. Journal of Water Supply: Res Technol-AQUA, 55, 257-268, 2006.
[19]  Hassell, C. Rainwater harvesting in the UK – A solution to increasing water shortages? Proceedings of 12th International Conference on Rainwater Catchment Systems, New Delhi, India, 6, 2005.
[20]  Environment Agency. Saving water: on the right track. A summary of current water conservation initiatives in the UK March 1999. Environment Agency, National Water Demand Management Center, Worthing, West Sussex, UK, 1999a.
[21]  Lee, J.H., Bang, K.W., Ketchum, L.H., Choe, J.S. and Yu, M.J. First flush analysis of urban storm runoff, Science of the Total Environment, 293 (1-3), 163-175, 2002.
[22]  Wu, C., Junqi, L., Yan, L. and Wenhai, W. First flush control for urban rainwater harvest systems. Proceedings of 11th International Rainwater Catchment Systems Conference, Texcoco, Mexico, August 2003.
[23]  Martinson, D.B. and Thomas, T. Quantifying the First –flush phenomenon. Proceedings of 12th International Rainwater Catchment Systems Conference, New Delhi, India, November 2005.
[24]  Gould, J. and Nissen-Peterson, E. Rainwater Catchment Systems for Domestic Supply: Design, Construction and Implementation. Intermediate Technology Publications, London, 335, 1999.
[25]  Hassell, C. Rainwater harvesting in the UK – A solution to increasing water shortages? Proceedings of 12th International Conference on Rainwater Catchment Systems, New Delhi, India, 6, 2005.
[26]  Woods-Ballard, B., Kellagher, R., Martin, P., Jeffries, C., Bray, R. and Shaffer, P. The SUDS Manual. Construction Industry Research and Information (CIRIA), Report C697 London, 606, 2007.
[27]  Sekar, I. and Randhir, T.O. Spatial assessment of conjunctive water harvesting potential in watershed systems. Journal of Hydrology, 9 (24), 1-14, 2006.
[28]  Kahinda, J.M., Taigbenu, A.E. and Boroto, J.R. Domestic rainwater harvesting to improve water supply in rural South Africa. Physics and Chemistry of the Earth 32, 1050-1057, 2007.
[29]  Ghisi, E. and Oliveira, S.M. Potential for potable water savings by combining the use of rainwater and greywater in houses in Southern Brazil. Building and Environment, 42 (4), 1731-1742, 2007.
[30]  Sakellari, I., Makropoulos, C., Butler, D. and Memon, F. Modelling sustainable urban water management options. Proceedings of the Institution of Civil Engineers, Engineering Sustainability 158, ES3,143-153, 2005.
[31]  Millerick, A. A comprehensive and systematic design approach. Proceedings of 2nd National Conference on Sustainable Drainage. 20-21 June 2005, Coventry University, UK, 9-18, 2005.
[32]  Abdulla, F.A. and Al-Shareeff, A.W. Roof rainwater harvesting systems for household water supply in Jordan. Desalination 243, pp. 195-207, 2009.
[33]  Helmreich, B. Hom, H. Opportunities in rainwater harvesting. Desalination, 248 (1-3), 118-124, 2009.
[34]  Farreny, R., Gabarrell, X., Rieradevall, J. Cost-efficiency of rainwater harvesting strategies in dense Mediterranean neighbourhoods. Resource Conservation Recycling, 55 (7), 686-694, 2011.
[35]  Gikas, G.D., Tsihrintzis, V.A. Assessment of water quality of first-flush roof runoff and harvested rainwater. Journal of Hydrology, 466-467:115-126, 2012.
[36]  Chiu, Y.R., Liaw, C.H. and Tsai, Y.L. Harvesting rainwater, an innovative approach to easing urban water-energy dilema. 14th International Conference on Rainwater Catchment Systems. Kuala Lumpur, 2009.
[37]  Hashim H., Hudzori, A., Yusop Z., Ho W.S. Simulation based programming for optimization of large-scale rainwater harvesting system: Malaysia case study. Resource Conservation Recycling, 80, 1-9, 2013.
[38]  Rashidi M.H., Saghafian B., Haghighi F. Assessment of residential rainwater harvesting efficiency for meeting non- potable water demands in three climate conditions. Resource Conservation Recycling, 73, 86-93, 2013.
[39]  Bocanegra-Martinez A, Ponce-Ortega J.M., Napoles-Rivera F., Sena-Gonzaez M., Castro-Montoya A.J., El-Halwai, M.M. Optimal design of rainwater collecting systems for domestic use into residential development. Resource Conservation Recycling, 84, 44-56, 2014.
[40]  Jha M.K., Chowdary V.M., Kulkarni Y., Mal B.C. Rainwater harvesting planning using geospatial techniques and multicriteria decision analysis. Resource Conservation Recycling, 83, 96-111, 2014.
[41]  Sample, D.J., Liu, J. Optimizing rainwater harvesting systems for the dual purposes of water supply and runoff capture. Journal of Clean Production, 75, 174-194, 2014.
[42]  Aladenola, O.O. and Adeboye, O.B. Assessing the potential of rainwater harvesting. Water Resources Management, 24, 2129-2137, 2010.
[43]  Lade, O., Oloke, D., Chinyio, E. and Fullen M. Potential for potable water savings by using rainwater: A case study of Ibadan, Nigeria. International Journal of Advancements in Research and Technology, 2 (4), 117-131, 2013b.
[44]  Coombes, P.J., Kuczera, G., Argue, J.R., Cosgrove, F., Arthur, D., Bridgman, H.A. and Enright, K. Design, monitoring and performance of the water sensitive urban development at Figtree Place in Newcastle. Proceedings of the 8th International Conference on Urban Storm Drainage, Sydney, Australia, 1319-1326, 1999.
[45]  Appan, A. A dual-mode system for harnessing roofwater for non-potable uses. Urban Water 1 (4), 317-321, 1999.
[46]  Fewkes, A. The use of rainwater for WC flushing: The field testing of a collection system. Building and Environment 34, 765-772, 1999.
[47]  Adhityan, A. A dual-mode system for harnessing roofwater for non-potable uses. Urban Water 1, 317-321, 1999.
[48]  Peter, A. A. and Mberede, L.O. Improvement on the harvested rainwater quality in rural areas of Southern Nigeria. Poster Presented at 10th IRCSA Conference, Mannheim, Germany, 2001.
[49]  Ghisi, E., Montibeller, A. and Schmidt, R.W. Potential for potable water savings by using rainwater: An analysis over 62 cities in Southern Brazil. Building and Environment, 41 (2), 204-210, 2006.
[50]  Ghisi, E. and Oliveira, S.M. Potential for potable water savings by combining the use of rainwater and greywater in houses in Southern Brazil. Building and Environment, 42 (4),1731-1742, 2007.
[51]  Ghisi, E., David a Fonseca, T. and Rocha V.L. Rainwater harvesting in petrol stations in Brasilia: Potential for potable water savings and investment feasibility analysis. Resources Conservation and Recycling 54 (2), 79-85, 2009.
[52]  Zhang, D., Gersberg, R.M., Wilhelm, C. and Voigt, M. Decentralised water management: Rainwater harvesting and greywater reuse in an urban area of Beijing, China. Urban Water, 6 (5), 375-385, 2009.
[53]  Thomas, T. RWH performance predictor for use with coarse (i.e. monthly) rainfall data. Domestic RoofwaterHarvesting Research Programme Report RN-RWH04, Development Technology Unit, University of Warwick, 2002.
[54]  NPC, Nigeria Population Commission Official Result for 2006 House and Population Census Figures, Bureau for National Statistics Abuja, Nigeria. Online: [accessed 27 June 2015], 2006.
[55]  Kellagher, R. B. and Maneiro Franco, E. Rainfall collection and use in developments; benefits for yield and stormwater control. WaND Briefing Note 19; WP2 Briefing Note 2.15; Report SR 677 Release 3.0, HR Wallingford, UK, 84, 2007.
[56]  Environment Agency, Harvesting rainwater for domestic uses: An information guide. Environmental Agency, Bristol, UK, 2003b.
[57]  Memon, F.A., Ton-That, L. Butler, D. An investigation of domestic water consumption through taps and its interaction with urban water flows. Water Science and Technology: Water Supply, 5-6 (7) 69-76
[58]  Cunliffe, D.A. Guidance on the Use of Rainwater Tanks. National Environmental Health Forum Monographs, Water Series No. 3. Openbook Publishers, Rundle Mall, Australia, 29, 1998.
[59]  Yaziz, M.I., Gunting, N., Sapari, N. and Ghazali, A. Variations in rainwater quality from roof catchments. Water Research, 23 (6), 761-765, 1989.
[60]  Coombes, P.J. Rainwater tanks revisited: new opportunities for urban water cycle management. PhD thesis. Newcastle University, New South Wales, Australia, 2002.
[61]  Ghisi, E. and Ferreira, D.F. Potential for potable water savings by using rainwater and greywater in a multi-storey residential building in southern Brazil. Building and Environment, 42 (7), 2512-2522, 2007.
[62]  Fewkes, A. The instrumentation and field testing of a rainwater collector. Proceedings of 8th International Conference on Rainwater Catchment Systems, Tehran, Iran, April 1997.
[63]  BS 8515. Rainwater harvesting systems – code of practice. Technical committee CB/506. UK: BSI British Standards: 2009.
[64]  Government of Ontario. Ontario guidelines for residential rainwater harvesting systems handbook. 1st edition Toronto, ON, Canada: Government of Ontario, 2010.
[65]  ARSCA. Rainwater catchment design and installation standards. Tempe, AZ, USA: American Rainwater Catchment Systems Association (ARCSA), 2009.
[66]  ETA 0701. Rainwater harvesting systems in buildings. National Association for the Quality of Buildings Installations (ANQIP), Technical Committee 0701, Portugal, in Portuguese 2012.
[67]  ABNT NBR 15527. Rainwater –catchment of roofs in urban areas for non-potable purposes–requirements. Brazil: The Brazilian Association of Technical Standards (ABNT), in Portuguese, 2007.
[68]  Palla, A., Gneco, I., Lanza, L.G. Non-dimensional design parameters and performance assessment of rainwater harvesting systems. Journal of Hydrology, 401, 65-76, 2011.
[69]  Ward, S., Memon, F.A. and Butler, D. Rainwater harvesting: Model-based design evaluation. Water Science and Technology, 61 (1), 85-96, 2010.
[70]  Campisano, A. Modica, C. Optimal sizing of storage tanks for domestic rainwater harvesting in Sicily. Resource Conservation Recycling, 63, 9-16, 2012.
[71]  Basiger, M., Montalto, F., Upmanu, L. A rainwater harvesting system reliability model based on nonparametric stochastic rainfall generator? Journal of Hydrology, 392 (3-4), 105-118, 2010.
[72]  Fewkes, A. and Butler, D. Simulating the performance of rainwater collection and reuse system using behavioural models. Building Services Engineering Research and Technology, 21, pp. 99-106, 2000.
[73]  DMS, Weather Observation Station. Department of Meteorological Services, Samonda, Ibadan 2010.
[74]  IITA, Weather Observation Station. International Institute of Tropical Agriculture, 2010.
[75]  Adekalu, K.O., Osunbitan, J.A. and Ojo, O.E. Water sources and demand in South Western Nigeria: Implications for Water Development Planners and Scientists. Technovation, 22 (12), 799-805 (7), 2002.
[76]  UN, Water Supply and Waste Disposal Poverty and Basic Need Series, September Warm Glacial Climate. Science 1997, 1257-1266, 2002.
[77]  Memon, F.A., Butler, D. Water consumption trends and demand forecasting techniques. In water Demand Management, Butler D. and Memon, F.A, (eds) IWA publishing, ISBN 18 43390 787, 1-26, 2006.
[78]  Environment Agency, A scenario approach to water demand forecasting. National Water Demand Management Center, Environment Agency, West Sussex, UK, 2001.
[79]  Sim, P., McDonald, A., Parson, J., Rees, P. The options for UK Domestic Water Reduction – A Review, Working Paper 05/03 version 1.0, 2005.
[80]  DCLG, Code for sustainable homes: Technical guide. Department for Communities and Local Government, Communities and Local Government Publications, HMSO, London, 2007.
[81]  Butler, D. The influence of dwelling occupancy and day of the week on domestic appliance wastewater discharges. Building and Environment, 28 (1), 73-79, 1991.
[82]  HMSO, Water Supply (Water Fittings) Regulations 1999. Statutory Instruments No. 1148, Water Industry, England and Wales, HMSO, London, 240, 1999.
[83]  Thackray, J.E., Crocker, V. and Archibald, G. The Malvern and Mansfield studies of domestic water usage. Proceedings of the Institute of Civil Engineers, 64, 37-61, 1978.
[84]  SODCON, Survey of domestic consumption. In Water Demand Management. Anglian Water, Normich, 361, 1994.
[85]  Fewkes, A. The use of rainwater for WC flushing: The field testing of a collection system. Building and Environment, 34, 765-772, 1999a.
[86]  Chambers, V.K., Creasey, J.D., Glennie, E.B., Kowalski, M. and Marshallsay, D. Increasing the value of domestic water use data for demand management- summary report. WRC collaborative Project CP 187, Report no. P6805, Swindon, Wiltshire, UK, 2005.
[87]  Lallana, C., Krinnner, W., Estrela, T., Nixon, S., Leonard, J. and Berland, J.M. Sustainable water use in Europe. Part 2: Demand management. European Environment Agency, Copenhagen, 94, 2001.
[88]  Grant, N. Water Conservation Products. In: Butler, D. and Memon, F.A. (Eds). Water Demand Management. IWA Publishing. London, 236-279, 2006.
[89]  Wittwer, J. Monte Carlo Simulation in Excel. A practical guide for Science and Engineering and Financial Risk Analysis. Online: [accessed 16 July 2015].