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Selected Abstracts from Concurrent Sessions
Improving Water Security in Tsunami Effected Areas in Sri Lanka Through Domestic Rain Water Harvesting
T. Ariyananda , Director, Lanka Rain Water Harvesting Forum, tanuja@sltnet.lk
Abstract
Since the tsunami of 26th December 2004 the water sources around the coast of Sri Lanka still remain contaminated. Sea water intrusion to wells has made the present sources which are mainly wells unusable even after desalination. It is estimated that 10 pipe bourn water schemes were damaged and 50,000 house connections were damage during the tsunami. In addition it is estimated more than 60% of the wells are still microbiologically contaminated. Therefore, the people living in these areas face serious problems in fetching quality water for domestic use. Especially since the bowsers supply of water by the donor agencies and government is also now diminishing.
Rainwater harvesting (RWH) through roof catchments has been introduced in three of the tsunami effected districts in Sri Lanka. More than 1000 rain water harvesting units have been built for the tsunami reconstructed houses in two districts in the south and one district in the east. Rainwater harvesting through roof run off has significantly address the shortage of domestic water at household levels. The benefits experience by these householders are : Easy access to clean drinking water, less time spend on collecting water, skilled enhancement in the village, less reliance on external water providers, more water security at household level, better sanitation practice due to more water available.
Government policy and support too has encouraged the uptake of rain water harvesting in the tsunami reconstruction process. Ministry of Urban Development and Water Supply incorporated rain water harvesting in the design of tsunami reconstructed houses, which is now an essential requirement in a standard tsunami house. In additional the policy propose to amend legislation (UDA by Laws) to incorporate RWH in new construction in other areas of the country as well.
Characteristics of Rainfall & Its Effect on Storage Volume for Rainwater Harvesting in South and North Cities in China
W. Che1, N.-Y. Tang1, H.-Y. Li1
H. Liu 2, G.-H. Meng 2，H.-L. Wang2
1.Institute of Environmental and Energy Engineering, Beijing University of Civil Engineering and Architecture, No.1 Zhanlanguan Rd., Beijing 100044, P. R. of China. (E-mail: chewu812@163.com)
2.Beijing Water Conservation & Management Centre, Beijing 100871, P. R. of China (E-mail: whling88@sohu.com )
It is very important to develop of urban rainwater harvesting system and to plan or design of a high efficient system available for local conditions that understanding various rainfall characteristics in south and north cities of China. In this article, four typical cities were chosen respectively from south and north to be analyzed. Average annual and monthly rainfalls in these cities were statistically analyzed. On this basis, it was concluded that the characteristics would affect the plan or design of a rainwater harvesting system, especially the volume of storage basin would be affected. It could be a reference for decision-making and design of rainwater harvest system in south and north cities of China.
Keywords: Rainfall characteristics; South/north cities
Rainwater Catchment and Sanitation System of Architecture School of the University of Guadalajara
J. Gleason 1, F. Cordova2, J. García2, J. Jimenez2, V. Reynoso2
1 University of Guadalajara, agleason@cuaad.udg.mx
2 University of Guadalajara
The present paper describes the Rainwater Catchment and Sanitation Projects of the Art, Architecture and Design Center of the University of Guadalajara or CUAAD (Spanish abbreviations). CUAAD belongs to the University of Guadalajara’s network and one of its main areas of academic work and investigation, is the relation between urban design and architecture with the environment. In terms of administration and management of the water resources CUAAD has problems such as: infrastructure of supplying and sanitation on the limit of its life utility; inadequate disposition of wastewater which is throw away in the Ravine of Huentitán; it doesn’t take advantage of landscaping potential of the location; and lack of planning and incapacity in the hydraulic-sanitation network.
The proposal tries to link many aspects in integral way such as: rainwater catchment actions, which can be oriented to the irrigation, the regulation of stormwater overflows by ponds integrated to a landscape proposal; the hydraulic-sanitation infrastructure restoration actions, (correction and renovation of the water supply and drainage networks), and the separation of drainage into stormwater and sanitary system; the removal of the old septic tank grave that at the moment is in use and the implementation of Biodigesters.
Institutional, Policy Development and Capacity Building for Promotion of Rain Water Harvesting in Sri Lanka
A.H.Gunapala D S S Abeysuriya (Ms)
E-mail: csrws@eureka.lk
Project Secretary – ADB Third Project - National Water Supply and Drainage Board -Sri Lanka.
Abstract
At Present, Sri Lanka has high rainfall volume being about 5900cu.m/ capita per year. By its geographical position and the location of its central hills, it is blessed with two monsoons namely; the South West (May- September) and North East (December- February), interspersed by two inter-monsoons. Island-wide receive some amount of rain annually even though varying in intensity, but never fails entirely.
Currently, Sri Lanka’s population is about 20 million and communities in most of the areas scarcity of safe drinking water. However, present coverage of safe drinking water is 74%. The country has to reach the coverage of 85% and 100% respectively in 2015 and 2025 to achieve the Millennium Development Goals. The Rain Water Harvesting (RWH) also contributes to achieve above targets. In this context, Sri Lanka has to develop a policy and strategy as well as legislative support for introducing rain water harvesting system to encourage the community and the institutions. All those arrangements have to be targeted to promote rain water harvesting system as one of the options for drinking water. This paper illustrates the policy objectives, institutional arrangements and capacity building programmes that are to be introduced in Sri Lanka in order to promote RWH.
Financing Mechanisms for Roofwater Harvesting
An example from Uganda
H.Hartung and C.Rwabambari
FAKT, Stuttgart, Germany, hansfhartung@aol.com
CCS, Mbarara, Uganda, rwabambari_c@yahoo.com
Abstract
Roofwater harvesting in Africa has too long been implemented only within an aid projects setting. Work and further development has been concentrated on the hardware aspects (like optimised construction of the tank, simple guttering systems, foul-flush devices, filters, etc.). The software part such as influencing the national water policy to integrate roofwater harvesting, developing suitable strategies for mainstreaming or advocacy on different levels has long been neglected. The paper wants to show the importance of software aspects, especially financial mechanisms for roofwater harvesting to support its further spread. An example from Uganda underlines the importance of financial issues. Microfinance institutions report a significant increase in their reputation and membership due to their engagement in roofwater harvesting. The development of different financial mechanisms is traced back and the implications discussed, including possible replication in other regions/countries.
Urban Rainwater Collection Strategy to Reduce Water Crisis in the City of Mashhad (IRAN)
J. Tabatabaee Yazdi,
Ass. Prof., Khorasan Agri. and Nat. Res. Research Center,
Email: tabatabaee_j@ yahoo.com
Abstract
The ever increasing urban demand for water resources stemming from factors such as the population increase, expansion of cities, and contamination of rainwater runoff with sewage residuals and industrial chemical materials has posed great problems at present and created undesired lookout for future generation living in urban regions. In this study the potential use of rainwater harvesting is examined in the holly city of Mashhad and framework is developed as a countermeasure for water shortage which is now seriously exposed. Based upon the meteorological condition, long term records are used to determine the average and maximum rainfall induced runoff. These data supposed to be useful for designing conveyance structure and spillway. Daily records are used to examine the required storage capacity with respect to proposed catchment size and acceptable crops requirement shortages. A computer program is used to iterate a full rang of daily records during the recent 20 years time for different catchment to crop area ratios. A design chart is developed to be used for other city districts and towns with similar climate condition.
The microbiological quality of roof-collected rainwater
of private dwellings in New Zealand
S. Abbott1 , B. Caughley1 & J. Douwes2.
1Institute of Food Nutrition and Human Health, Massey University, New Zealand
2Centre for Public Health Research, Massey University, New Zealand
1Email: S.E.Abbott@massey.ac.nz
Abstract
In this 5 - year study we investigated the microbiological quality of roof-collected rainwater samples of 560 private dwellings in New Zealand. At least half of the samples analysed exceeded the minimal acceptable standards for contamination and 41% of the samples showed evidence of heavy faecal contamination. The likely sources of the faecal contamination were faecal material deposited by birds, frogs, rodents and possums, and dead animals and insects, either on the roofs or in the gutters, or in the water tank itself. Many of the roof water supplies surveyed revealed deficiencies in the use of rainwater catchment systems and components. In a significant number of supplies where we found heavy faecal contamination there was evidence of lack of maintenance; inadequate disinfection of the water; poorly designed delivery systems and storage tanks; and failure to adopt physical measures to safeguard the water against microbiological contamination.
The results of this study indicate that the information on the safe collection and storage of roof-collected rainwater seems not to be reaching many users in New Zealand. Roof water users need more information pertaining to their roof water supplies but we believe improvements are necessary in the dissemination of this information.
Treatment of Roof-Harvested Rainwater Using Metal (Hydr)oxide-Coated Sand Filter
V Meera1, M Mansoor Ahammed2
1Department of Civil Engineering, School of Engineering, Cochin University of Science and Technology, Kochi – 682 022, India
2 Department of Civil Engineering, SV National Institute of Technology,
Surat – 395 007, India. Email : mansoorahammed@gmail.com
Abstract
Since many rural communities in developing countries use roof-harvested rainwater as their primary water source for drinking, there is a need to develop low-cost, efficient and easy-to-use point of use devices/methods for treatment of harvested rainwater. Sand coated with iron (hydr)oxide and manganese oxide are known for their capacity to remove bacteria and heavy metals, respectively, from water. In the present study, a filter medium consisting of 7.5 cm deep manganese oxide-coated sand layer over a layer of 7.5 cm iron (hydr)oxide-coated sand was used to treat roof-harvested rainwater. Short-duration column tests with this filter employing roof-harvested rainwater showed the potential of this filter. It removed more than 99% coliforms and 96% lead from the influent. In long-duration column tests using the same filter, up to 500 bed volumes of harvested rainwater (pH 6.8, turbidity 2.7 NTU, total coliforms 1500 MPN/100 mL, lead 0.38 mg/L) could be treated. The effluent characteristics were: total coliforms <3-7 MPN/100 mL, heterotrophic plate count 260-580 CFU/mL, lead 0.01-0.03 mg/L and turbidity 0.7-0.9 NTU. The study thus showed the potential of the sand coated with iron (hydr)oxide and manganese oxide as filtration/adsorption media for use in low-cost household water filters for purification of roof-harvested rainwater.