This study regards disc and strip sources of water on the soil surface. The primary interest in disc sources stems from the widespread application of tension infiltrometers although the analysis is also relevant for shallow ponds. There has been less interest in strip sources although the results are relevant to irrigation utilizing shallow furrows as well as wetted bands arising from drip irrigation. Generally, the most common approaches that have been used for describing flow from disc sources are either the use of R. A. Wooding's equation or strictly numerical modeling based on Richards' equation. The investigation here investigates a third approach that the difference between the three dimensional cumulative infiltration expressed per unit of wetted area and an equivalent one-dimensional flow is linearly related to time. This idea is presented by K.R.J. Smettem, J.Y. Parlange, P.J. Ross and R. Haverkamp in 1994. We test their assumption directly by doing numerical experiments (using HYDRUS-2D) and generalize results to include the strip as well as the disc source. The basic expression considered for the disc is shown in Eq.1 with I_3D [L] the cumulative infiltration per unit area of the disc source, S₀ [LT^-0.5] is the sorptivity, θ₀ [-] the volumetric water content at the disc source and θ_n [-] the initial water content in the profile. The I_1D [L] is the one-dimensional cumulative infiltration and γ is a “constant.” The numerical experiments proceed by choosing three soils of contrasting texture based on the hydraulic functional forms of M. Th. van Genuchten. For each soil, boundary conditions are chosen, a disc radius is chosen and the left hand side of the above equation evaluated. The figure includes the resulting plot for a loamy soil, a disc radius of 10 cm, a saturated soil at the disc source and an initial water content which is 10 percent of the difference between residual and saturated water content. Comparison to a best fitting linear curve results in a coefficient of determination of essentially 1. A corresponding value of γ(dimensionless) is found to be 0.805. Additional cases were used with all three soils and using various disc radii, boundary tensions and initial water contents. Observations were that the linear relationship with time generally is very good, but γ takes on values between 0.72 and 1.22. An effort was made to relate the value of γ to the soil hydraulic parameters and disc radius as well as the boundary and initial conditions. Results for the strip are also shown in the figure and also show a reasonable linear relationship using Eq. 2 with I_2D [L] defined appropriately for the strip. The relationship is found by assuming the “edge effect” per unit length of contact between the source and the surrounding soil is the same for both the two and three dimensional cases. The γ in this case is 0.612. The general conclusions are that the differences between the cumulative infiltration per unit source area for the multiple-dimensional sources and the one-dimensional sources are linearly related to time, but that a single value of γ is generally inadequate. Once γ is defined, the disc or strip infiltration follows immediately if the corresponding one-dimensional solution is known without the necessity of performing a two or three-dimensional simulation.