Rain water harvesting: a sustainable alternative for domestic water supply in South–Western Nigeria: in the case study of Ado-Odo/Ota LGA Ogun State

Abstract Nigeria is currently facing various environmental challenges such as water scarcity and water quality; which is one of the largest environmental problems. However, the available supply of renewable water is short of the demand in Nigeria. Researchers have studied many alternative to better solve the emerging water supply problem. This study considers rainwater harvesting as an alternative source of water to ameliorate the possible scarcity. To better understand common practises in the rain water harvesting community and motivation for collecting harvested rainwater a socio-demographic survey was conducted in four communities in Ado-Odo/Ota Local Government Ogun State Nigeria to determine the rate of water consumption and supply from current water sources. A total of 400 questionnaires were administered to various household and the data collected through the survey were analysed using SPSS and selected statistical methods. Rainfall data for Ota was obtained and it was to calculate the cumulative runoff in a year was determined for roof sizes are ≤ 75m2. This study demonstrated among other things that rainwater harvesting has the potential of contributing significantly to solving the problems of water shortage suffered not only by the rural-poor communities but also in the urban areas where conventional modes of water supply have failed to provide the desired level of service.</jats:p

A Modified Laboratory Approach to Determine Reaeration Rate for River Water

It is reported that reaeration rates determined from laboratory investigation may not suit well in predicting reaeration rate of natural streams. Sampling method during reaeration experiment is a potential source of error in laboratory estimation of reaeration rate coefficient for river waters, which has been addressed in this research. A modified method based on sampling procedure in a flume was adopted to develop a reaeration rate equation for Pusu River in Malaysia,which is demographically a very important river. An important feature including several culverts along the course of the river was also considered to model dissolved oxygen (DO) concentration.DOwas calibrated and validated using water quality analysis simulation program (WASP) considering appropriate kinetic rate coefficients for Pusu River. Performance of the new reaeration rate equation and other process equations in the calibration and validation data was assessed in terms of root-mean-square error (RMSE), mean error between observed and predicted data and R2 value. Study results revealed that the equation developed in B Abdullah Al-Mamun [email protected] Md Nuruzzaman [email protected] http://waterzaman.weebly.com/ Md Noor Bin Salleh [email protected] 1 Department of Civil Engineering, Rangpur Engineering College, Rangpur 5403, Bangladesh 2 Department of Civil Engineering, Kulliyyah of Engineering, International Islamic University Malaysia (IIUM), 53100 Kuala Lumpur, Malaysia 3 Bioenvironmental Engineering Research Center (BERC), Kulliyyah of Engineering, International Islamic University Malaysia (IIUM), 53100 Kuala Lumpur, Malaysia this research considering the impact of culverts on reaeration rate predicted DO in Pusu River with improved accuracy as compared to the other equations. RMSEs were found to be 0.083 and 0.067 mg/L for calibration and validation data, respectively. Mean errors of observed and model-predicted data were 0.06 and 0.05 mg/L for calibration and validation,respectively. The R2 value was 0.99 in both cases. The study results facilitate accuracy in future studies on DO of Pusu River