The paper tells that over the last 25 years, the “freeboard and spillway arrangements” for reservoirs in the UK have been based on the unit hydrograph rainfall-runoff and losses model. The model was used to obtain the design of the events of flood that would enable to determine whether the prevailing arrangements might convene the floods. The characteristics of drainage such as the area of the basin, the basin shape, the type of soil, use of the land, drainage density and drainage network topology, and the rainfall characteristics that include duration of the rainfall, its intensity, its distribution and direction are the different factors that might affect the shape of the hydrograph. The unit hydrograph model was established in the year 1975. However in the recent years, the model has been revitalized and hence replaced with the ReFH or Revitalized Flood Hydrograph Model that comprises three significant components – the loss, routine and baseflow models. The seasonality of the floods is also measured through this model such that factors of seasonal corrections are applied to the estimates of the flood designs and conditions with the purpose of meeting the floods. The Reservoirs Act 1975 led the responsibility of the law to protect the reservoirs in the UK. Approximately 25000 cu m of water is held by the UK reservoirs and the Act covers around 2500 reservoirs under its framework. England, Wales and Scotland are under the purview of this Act.
However, the Act does not cover the reservoirs across the Northern Ireland. Undertakers, Enforcement Authorities, Qualified Civil Engineers, and the Secretary of the State are the four major persons or organizations in charge under the Act who have the different responsibilities in regard to the protection of the UK reservoirs. The undertakers are referred to the owners of the reservoirs and thus have the most significant responsibility for the reservoir’s safety. The role of the enforcement authorities comprises monitoring the performance of the undertakers. The design and supervision of the constructions of the reservoirs focusing on the safety issue are the responsibilities of the qualified engineers. The Secretary of State is in charge of supervising the activities of the other three major persons or organizations (The British Dam Society, 2010). It is in the last five years that the risks arising out from the reservoirs have been considered significantly as a matter of concern. The risk factors have arisen as a result of the uncontrolled discharge of water from the reservoirs threatening the lives of the heavily populated regions where the reservoirs are located in the UK. The reservoir safety legislation was introduced in the year 1930. Since then such disastrous incidents have not occurred. However, there have been several incidents that could have taken several lives (Morris, Hewlett & Elliott, n.d., p.3). Not only are the risks associated with such reservoirs, but also several advantages and disadvantages and impacts are associated related to the surrounding environment that might occur as a result of the constructions and use of the reservoirs in the UK. The present study focuses on the impacts that UK reservoirs have on its surrounding environment. The following figure represents the overall reservoir stocks in England and Wales between 1996-2005: Figure 1: Overall Reservoir Stocks in England and Wales 1996-2005 (Water Levels, 2007). 2. Literature Review: For a better understanding of the literature relating to the impact of reservoirs in the UK on the surrounding community it would be significant to gain a proper understanding of reservoirs and their function in the society. This will allow for