Telescopic water intake structures have an important role in the water management system. Telescopic water intake has high mobility and wide field of application; at the same time, it is very simple and convenient to operate. But despite these advantages, there is no structural solution for flow energy dissipation in the downstream, no exact calculation method of flow energy dissipating structure, no structural solution to prevent floating objects entering inside the water intake structure, and no structural solution to stop water intake operation. In this regard, the purpose of this research is to improve the design of the existing telescopic water intake, to develop the design and calculation method for the stilling well. Structural solution for flow energy dissipation by means of stilling well is proposed. To protect the water intake from the ingress of floating objects and debris, protective mesh is designed. A shutter is provided to stop water intake operation of the unit. Methodology for analytical hydraulic calculation of a stilling well has been developed. In order to verify above mentioned calculation methodology, analytical calculations and numerical modeling of specific example were performed. The following results of analytical calculation of the main parameters of stilling well were obtained: length and depth. The results of numerical modeling demonstrated effective energy dissipation in the stilling well and acceptable flow velocity at the entrance to the channel.