This paper presents the application of interval arithmetic technique for balanced radial distribution system power flow analysis with sparsity technique. Only single dimensional arrays are used for implementation of the proposed method. This reduces a lot of memory and CPU time as it minimizes the search process in identifying the adjacent nodes and branches beyond a particular node.  Interval arithmetic takes care of the uncertainty in the input parameters and provides strict bounds for the solution of the problem. In this paper uncertainties only in the input load parameters are considered. Computationally the proposed method is very efficient and it requires less computer memory. The results obtained by the proposed method are compared with the results obtained from repeated load flow simulations.