Develop of methodology for determination range of ecological acceptable dicharges in urban drainage

Urbanization causes significant changes of surface waters, especially running waters. For a long period of time interest about all these problems were limited only on changes of hydraulic and hydrological conditions in running waters as resource of water for different users (delivery of required amount of water). The delivery of required water amount was supported by technical changes of rivers (creeks) character (reservoirs, damps, etc). This effort to deliver required amount of water to all users and a flood protection did not impact the water body always positively and rivers (creeks) were significantly changed. The present European legislation, especially Directive 2000/60/ EC, requires that all water bodies will reach good ecological status until year 2015. The first step is to monitor quality of aquatic ecosystem from different point of view; chemical, morphological and hydraulic and finally biological status. The monitoring of chemical quality is done for a few decades and also biological quality is observed during the last two decades with increasing emphasis. But the impact of changes in morphology and discharge on aquatic ecosystem was neglected for a long time. Changes in morphology and discharges play an important role especially in small urban creeks, which are heavily impacted by urban drainage and discharge from sewer system. Frequent overflows from sewer and discharge variation in the creek put a high demand not only on the watercourse but also on the aquatic biota. Impact of these events makes either deficient discharge or discharges, which cause an artificial flood. Both cases could destroy the watercourse and aquatic life so heavily, that it would exceed their recovery potential. Identification of ecological discharge range is necessary to avoid these types of negative impacts and also it is important for sustainable water management and revitalization of impacted watercourses.
Mean goal is determinate range of ecological discharges and suitable microhabitat parameters.