WATERWAYS FOR BRIDGES AND DETERMINATION OF EFFECTIVE WIDTH OF LINEAR WATERWAY, AND DESIGN CALCULATIONS FOR THE DATA BASED WATERWAYS

While the Engineering department design for the culverts and small bridges, it is necessary to follow catchment, run-off, or storm water flows from catchments depending upon the number of factors such as intensity and duration of the rain fall, area and shape of the land and it's contours, initial stage of wetness, losses from evaporation (depending upon the climate) , percolation (depending upon the nature of the soil and its observing qualities, transpiration by the vegetation, etc etc.Other factors being equal, a catchment with a higher average rainfall will show a higher average loss. Floods from a larger area will take longer to rise and will be of less intensity relative to that area than floods from a smaller catchment. There are a number of complicated empirical formulae for calculating the run-offs of catchment which are not strictly accurate and give varying results, hence their use should be avoided. It will be appreciated that there are such a large number of factors in the estimation of run -off which are impossible to assess with any great degree of accuracy and correctness , as such the calculations should be as simple as possible, and local opinion must be obtained from the local people as related to the highest flood level during the previous maximum years available on the data reports or on the observations noticed from the area and circle covering this ultimatum of the discharge at particular points. For working out the discharge three cross sections should be taken at the stream site where it is proposed to build a bridge, one at the selected site, one upstream and another down stream. The site Engineer is too responsible to get this observation assessed by this or that way of the code for consideration, so that there should be no harmful afflux and accuracy may be obtained from the design data which should be processed before the competent higher authority for approval, before taking the work in hand, however it is regretted to point out the standard estimates prepared for similar works and doing needful, without taking into consideration the determination of effective width of the linear waterways and other aspects of the design parameters required for the accuracy and correctness of design and scope under provision made for the factor of safety in the structure, where as in the department of Rural development and panchayati raj there is no design cell in the district levels and also at the state levels of the Engineering department and the field staff adopting the equal standard depending upon the cost of structure, which may create problems during the rainy season particularly when there is no cross section of the linear waterways, as suggested above by the (IRC Code) :-- Er Fateh chand Guleria, Director RTI welfare Association registered number HPCD, 3552 , Bilaspur Himachal pradesh phone number, 9459334377