Management of stormwater runoff is considered a nationwide challenge. To deal with this challenge, many researches have been conducted to study initial stage of stormwater fee imposition. The objective of this study was to recommend a framework for stormwater fee imposition not only for funding the stormwater management programs but also for encouraging people to decrease impervious area. This study focused on, regulations, financial resources and international cases related to stormwater runoff management. Polluter pays principle, which is generally recognized environmental policy principle is regarded the basis of stormwater fee imposition. Three components suggested for the stormwater rate structure are 1) stormwater utility revenue requirement, 2) billable equivalent stormwater unit, 3) system unit cost. The key point of stormwater rate structure is the “Equivalent Residential Unit(ERU)”. The concept of an ERU is one residential area with a runoff coefficient. The runoff coefficient is that portion of rainfall that becomes runoff rather than infiltrating into the ground. In addition to this, this study took into account the observed data simulation for the separation of stormwater treatment expenditure from the comprehensive wastewater treatment cost.
As sewer flooding frequents due to localized and concentrated stormwater and increased non-permeable surface area after urbanization, building cities with sound water recycle and accordingly efficient management of rainwater is demanded. To do this, the existing sewage (including rainwater) fee imposition system should be philosophically evaluated. This study presents problematic issues of the existing domestic sewage fee imposition system considering the principle of sharing costs on the service of sewage and rainwater collection and treatment. Four methods to improve the existing sewage fee imposition system are suggested: 1) imposing stormwater fee according to Polluter Pays Principle, 2) clarification of the share of public sector, 3) reducing or exempting the sewerage fee for inhabitants reducing urban runoff by constructing their own rainwater management facilities, 4) imposing charge for discharging rainwater to sewers due to new development action. Short, mid, or long term planning for rainwater management is recommended considering the situation of each municipality.
Purpose: Town of Woldia, a semi-arid region in the Northern Wollo region of Ethiopia, faces water supply shortage in general, though the town possesses a running stream of clean water throughout the year. This study is aimed at analyzing the possibility of using rainwater for water scarcity and non-potable water needs of the Woldia University. A careful study and analysis have been made to assess the feasibility of using rainwater in place of the tap water supply. Research design and methodology: This study was done inside the main campus of Woldia University located in Woldia town. The runoff water from the roof of buildings was studied, by the time of rainfall in the town. Also, the budget needed for implementing a rainwater harvesting system was calculated. Results: The findings of the study clearly indicates that the requirements of the water to use for flushing, cleaning, and washing toilets in the administrative buildings and classrooms can be satisfied by using rainwater as an alternative to tap water. Conclusion: Based on the results the study finds it is benefitable for the Woldia University to install the rainwater harvesting system at the earliest to solve the water problems prevailing in the current situation.
본 연구는 현지(on-site) 빗물관리에 필요한 지붕면 누적유출용적 예측을 위한 경험식을 제안하였다. 건축물 지붕면은 좁은 면적으로 인해 기존 유출해석 기법의 적용이 어려운 것으로 파악되었으며, 지붕면 유출조건을 고려한 강우깊이(D)-누적유출용적(V)간의 이론적 관계식을 수립하였다. 2005년부터 2007년까지 2년간 실제 강우량과 지붕면의 유출용적을 측정하여 이론적 관계식으로 계산된 누적유출용적과 실측 누적유출용적 자료를 비교 검토하였다. 실측자료의