The oldest reservoir in Central Europe will be launched for the first time Valley Reservoir Jordan is the first lake in Central Europe, which was built to supply the city with water. The emergence of historic tanks Jordan on Tismenickém stream is placed in historical sources in 1492. Reservoir embankment dam has a height of nearly 20 meters with a very steep slope vzdušního cheeks. The body of the dam has long been an important, very busy and easy substitute thoroughfare connecting the two parts of camp. Jordan was used for fish farming. Clearance Jordan were the most frequent opportunities to open the bottom drain is used to drain the tank. In 1830 discharge device was used during harvest last. After this date, the tank was drained and the drain pipe wooden apparently gradually clogged and devastated. The location of these pipelines is unknown and their recovery is real. Establishment of a new bottom drain the dam in the state of omitting tanks would be very risky, especially for the overall stability and tightness of the dam. This means that the tank is currently undrainable. In August 2002 the city of Tabor affected by the floods and was situated between structurally affected regions. It was also one of the reasons why the city of Tabor 23 12th 2004 applied for a building permit renewal retention basins Jordan - 1 Stage - bottom outlet and the authorization of the extraordinary handling the retention basin Jordan beyond the approved procedure for handling construction. The purpose of the construction is the establishment of a bottom outlet, which is an important operational element of the dam and the element to ensure its safety, especially during floods, crisis and emergency situations. After the construction of the bottom outlet is in the 2nd recovery phase retention basin is considered a total odbahněním tank (Stage 1 is solved only local dredging in the area of the dam and reservoir construction in the area). The main objective is to reduce dredging Jordan trophic burden, increase water quality and increase retention space. The deletion of Jordan will be a temporary disruption of habitat found specially protected animals. Terms Agency for Nature Conservation and Landscape are to be built dike in the middle of the pond, which will be during the construction of the water storage in the central and northern parts of the tank and in order to transfer animals from the southern to the northern part of the tank. Bottom outlet will be solved liner, mostly underground structures that allow draining the tank from its deepest point of the bypass for the dam pravobřežním engaging with the final outcome right from the waterfall spillway into the bed of the stream Tismenického and will be driven tunneling method ie blasting. It will be a tunnel length of 208.2 meters.