STUDY OF IN-STREAM STORAGE SYSTEM USING PIANO KEY WEIR

Abstract

In-stream storage is the storage volume of water at a given time in the channel or over the flood plain of the streams in a drainage basin or river reach. It stores the water into the stream itself. In this type of storage creation, there is no or very little spilling of the water is involved. Therefore it doesn't cause any submergence which is the greatest advantage of In-stream storage. In the present scenario of climate change, we need to create more storage for rising demand of water in rural and urban areas. Construction of dams, weirs result in submergence which leads to so many problems. Amongst which submergence is the major issue which leads to rehabilitation and settlement problems. Hence In-stream storage using Piano Key weir has a good prospects to help create storage without submergence and reduced sedimentation. Due to ongoing climate change effect, the water resources sector is facing increasing demand to meet various uses by the society. For e.g. • In agriculture the crop water requirement are increasing due to increasing evapotranspiration. • In hydropower projects, the evaporation increases the required amount of water. • The demand of water for navigation as well for drinking water is increasing. The conventional storage dams encounter stiff resistance from environment lobby because of R & R (Relief and Rehabilitation) and submergence. In the above context, the new concept of Piano Key weir is being researched to provide cost effective solution for creation of required storage volume in the channel itself without involving submergence and R&R (Relief and Resettlement), by cascade development of Piano Key weir infrastructure in a river as per feasibility. The Piano Key Weir is a particular geometry of weirs associating with a labyrinth shape and the use of overhangs, which reduces the basis length. This new shape of weir baptized Piano Key Weir represents an effective alternative for conventional barrages and dams and can increase in low cost the capacity of evacuation and\or the stocking of several existing dams.