Evaluation of the rainwater management practices: Dokuz Eylul University Tınaztepe Campus case study

In today's modern life, where the population, production and consumption have been increasing rapidly, humanity has forgotten to live in harmony with nature from micro scale to macro scale. Although nature continues to operate like a clock to renew itself and complete its missing parts, humanity continues to put obstacles and harm the cycle of nature. It is again in the hands of humanity to return from the mistakes that had been made, to allow nature to heal itself and to develop in harmony with it, which is to make life sustainable. It is agreed by all society, that today's clean water resources are becoming increasingly scarce, consumed, or rendered unusable by pollution. Rapidly growing population and consequently unplanned urbanization has caused the impermeable surfaces to increase in size. With increasing impermeable surfaces, the rainwater, the most important clean water source, are unable to feed underground and surface water resources and become unusable through runoff. However, rainwater, which is contaminated because of runoff, also decreases the quality of the surface water that connected to, and causes additional costs because increases the capacity of the infrastructure system. Despite accessing to clean water is an increasing problem from day to day, it is ironic to lose a source such as rainwater, and cause many additional processes and costs to treat. Within the scope of this thesis, the studies that can be done in accordance with the urbanization, are investigated so that the rainwater can be regenerated primarily to the nature, to feed the groundwater and to return to nature as a clean source. Afterwards, the reuse areas of the rainwater were evaluated as a clean water source instead of the mains water. In this study, firstly best management practices of rainwater have been investigated in detailed literatüre research. Within the scope of best practice management practices identified, a workspace is documented within the scope of the study. Tinaztepe Campus of Dokuz Eylül University was chosen as the study area by considering that education institutions are the best place for source of information sustainability to get involved to everyday life. Dokuz Eylül University Tinaztepe Campus in Izmir province has been in use for many years, but since the new constructions in the campus has gained momentum in recent years, suggestions have been made that the development within the campus can be made friendlier and sustainable with nature and buildings in the campus can be made into buildings with high water efficiency. The suggestions made to the campus have been evaluated. In the first phase of the study data, which could affect the surface run-off or use of rainwater at DEU Tınaztepe Campus were determined, and were arranged to be used in the study of the thesis. These are the geographical, geological, topographic, climate and meteorological characteristics of the campus and the amount of run-off in the campus. Three different urbanization conditions of the campus were evaluated in the study. These are: First, the near future scenario determined based on the development plan in which near future buildings of the campus can be, 2017-2018 conditions to represent today's campus and 2004 in order to get the farthest past data about the campus and represent the new development periods of the campus. Based on these three different conditions of urbanization, land use changes caused by increasing urbanization were determined, and the average run-off coefficients of the campus were calculated. Using the 10-year average rainfall data of İzmir province, the total run-off amount of each different land use type and urbanization was calculated separately. By calculating the change in the total run-off amount for the three different conditions, the change that the increased urbanization causes, in the runoff is revealed. As a result of this assessment, suggestions have been made for the new constructions in the campusto be made in the coming years and for the existing constructions to be revised in a more sustainable way. The first goal is to ensure that rainwater infiltrates the soil. First of all, it is suggested that all of the pavements in the campus should be revised as a paving stone. Afterwards, depending on the slope of the campus, it is aimed to reduce the average run-off coefficient and thus the run-off amount by forming sets of gravels on the pavement areas of some roads in the campus so without disturbing the comfort of walking. Afterwards, a green roof was suggested for the new buildings to be built in the campus. The changes in the suggestions given in these two steps are calculated in terms of the amount of run-off in the campus. In the second phase of the study, it was aimed to reuse the rainwater that could not reach the ground and to prevent consumption of a different clean water source. Accordingly, it has been suggested to use rainwater collected from the roofs of the buildings instead of the mains water in the toilet reservoirs in the Engineering Faculty 1, Engineering Faculty 2, Engineering Faculty 3, Faculty of Architecture, Faculty of Science and Literature, Faculty of Business Administration and Maritime Faculty buildings. Since separate measurement of water consumption in the reservoirs is not possible under this thesis study, by using the number of people, which can change over the years in the educational buildings in the campus, water consumption in the reservoirs were calculated using the water consumption calculation method of the LEED green building certificate issued by United States Green Building Council, with an excel calculator created within this study. In addition to the number of building users in the Excel calculator, roof area of the building and tank volume for predicted rainwater collection are entered. The formulation calculates the amount of water consumed in the reservoir and how much of this consumption can be met with rain water. Additionally, using the calculator created, how much municipal water can be saved assuming that a storage tank with a volume of 100 m3 is installed for each building and considering the number of people in the present situation. The need for treatment of this proposed rainwater harvesting system has also been assessed. In the light of these calculations, profit and amortisation periods of installing rain water harvesting system to the education buildings in the campus were calculated by taking into account the first investment and operating costs. According to the thesis studies, 26% in the reservoirs of the Engineering Faculty 1, 25% in the reservoirs of the Engineering Faculty 2, 25% in the reservoirs of the Engineering Faculty 3, 44% in the reservoirs of the Faculty of Architecture, 18% in the reservoirs of the Faculty of Science and Literature, 17% in the reservoirs of Faculty of Management and 30% in the reservoirs of the Maritime Faculty of the mains water efficiency was provided and the water requirement was met from the rainwater. The need for treatment of this proposed rainwater collection system has also been assessed. The need for treatment and filtration has been presented in the system. When the treatment requirements are evaluated, the Regulation on Rainwater Collection, Storage and Discharge Systems has been utilized. The parameters to be checked for the elimination of health concerns that may be experienced in the use of rain water as potable water have been determined. When the cost calculations of the system are carried out, the costs of the rainwater storage, the filtration system and the pump system are evaluated within the scope of the borrowing cost and system cost to be installed as the initial investment cost. Operating costs include water bill from mains water, maintenance and cleaning of the gutters, replacement and cleaning of the filter system, cleaning of the tank and electricity consumption and maintenance costs of the pump. In the light of these calculations, depreciation periods are calculated by evaluating the profit, first investment and operating costs of the rain water retention system that will be provided from the network water to the education buildings within the campus systems The system amortization periods vary from 1.3 to 8.8 years, while water efficiency is between 13% and 30% at the training buildings in the campus with the recommendation of using rainwater in reservoirs in the buildings. At the same time, as the LEED water efficiency calculation method was used in the calculation of water consumption amounts, a water efficiency evaluation was made for each building in terms of LEED. When evaluating LEED water efficiency, buildings were compared not only with reservoir consumption but also with all network water consumption. With the use of rain water in reservoirs, the buildings which are being evaluated within the scope of the thesis study have reached an efficiency rate of, 18% in total water consumption in Engineering Faculty 1, 17% in total water consumption in Engineering Faculty 2, 17% in total water consumption in Engineering Faculty 3, 30% in total water consumption in Faculty of Architecture , A total water consumption of 12% for the Faculty of Science and Literature, 10% for the total water consumption of the Faculty of Business Administration and 19% for the total water consumption of the faculty of Maritime Faculty. As a result of the work done, it has been determined that the runoff rates can be reduced 15% with some revisions made to land use, and approximately 2.5% with green roof application in the campus. In addition, the construction of a wet retention pond and surrounding green area at the lowest level in the campus, the formation of gutters and infiltration ditches on the sides of the new roads to be built in the campus, the application of green practices in the construction of new buildings in the campus,the green cleaning services in the campus and growth of green area are suggested. It is aimed to improve TSS, TN and TP removal with rainwater best management practices suggested to be implemented in the campus.