The Rainwater Utilization Of A Residential Subdistricts Of Xiangtan City

With the accelerating process of urbanization, the process of human interaction and social development of urban water resources and water resources as well as more and more serious, mainly for urban water shortages, urban water pollution is worsening, urban flood control flood pressures continue increase and falling water tables and other cities.So collect rainwater reuse is an effective means of improving the urban ecological environment, but also one of the important ways of water resources utilization and environmental sustainability achieved.This article is based on a residence community in Xiangtan city,the distribution and characteristics of rainfall in XiangTan is analyzed and also the variable and immutable objective factors of rainwater utilization in the city. The rainfall of Xiangtan is rich but the rainfall duration is uneven distribution. The average annual rainfall is1416.5mm, however, the available rainwater resource amount to53816000m3,the condition of water utilization is satisfied.The collection and reuse of rainwater mainly include the initial rainwater collection and treatment, the green roof, penetrating well,per-meabilitytube infiltration trench, depression, permeable ground pe netration rainwater collection and treatment facilities,at present, as well as the utilization system such as the’depression--seepage drainage’and ’natural water--the underground reservoir system’The original drainage system of the residential in Xiangtan city is rain and sewage diversion system. The rainwater direct discharge to the municipal rainwater pipe network after collecting by the rain water pipe network.There is no rainwater collection and treatment measures and the rainwater resource haven not been reasonable used.There are three waterscapes (a large artificial lake and two large fountain)in the residential,there may exist a great hidden danger of waterlogging, water resource waste and so on. The research take an eye on the deficiency of rainwater utilization. The’natural water--the underground reservoir system’is used in the design.Take the artificial lake as the core system, rainwater collection and pretreatment should be done in constructed wetland,then the depth processing should be done by storm deposition pool and filter.The rainwater after managed will be transported to water supplement water, road watering and greenbelt irrigation through water pump. At the same time, the analysis of rainwater water balance should that the average available rainwater resources capacity which is48530m3is much larger than the average total potable water which is23243.3m3,so the the conditions of rainwater utilization is fulfiled. We also analysis the engineering economic benefit of the rain water to prove the valuable to engineering application.