1.1 Background of the Study
Safe yield is the amount of water that can be withdrawn from an aquifer without significant ecological impacts. Managing water withdrawals from aquifers so as to not exceed “safe yields” is an emerging water supply issue. Significant ecological impacts could result from reductions in stream flow where groundwater discharge to the stream provides baseflow (Makinde, 2002). Water withdrawals can be balanced with return flows to the aquifer, which can include wastewater returns, after appropriate treatment, and collecting and infiltrating treated stormwater, artificial recharge (Makinde, 2002).
Determining safe yield limits is an evolving discipline. It requires a clear understanding of climate, hydrogeology, and ecological thresholds, especially where streams and wetlands are hydrologically connected to the aquifer. This requires careful integration between groundwater science and land-use policy (Fatoba; Omolayo & Adigun, 2014).
Water is essential for human settlements. Since prehistoric times, water availability has played a key role in determining the origin and fate of entire civilizations (Biswas, 2007). In today’s industrial societies, drinking and irrigation water supply is often taken for granted. This is because water infrastructures are solidly engineered and there are enough resources to build and maintain them. As a result, failures are rare and the population does not need to worry about taps running dry. However, access to water remains an issue in many regions across the world. In developing countries, where a productive well not only means hydration but also food security, hygiene, health, and, arguably, a better chance for education, a significant share of the population does not yet have access to improved water sources (UNICEF-WHO, 2015). Millions of people live more than one kilometer away from the nearest faucet, and walk several hours each day to provide water for such ordinary needs as drinking or cooking. More often than not, fetching water is a task for women and children—a task that is carried out at the expense of education and leisure, and often leads to chronic injuries and to missing out on opportunities for personal development (United Nations, 2010).