Water injection is widely used as an enhanced oil recovery strategy in the oil industry. Due to environmental regulations affecting conventional pressure transient tests, injection tests are expected to become increasingly important in well testing in the coming years. Reliable analytical solutions for injection and falloff tests have been established and have been also successful in recovering reservoir properties like water and oil mobility. This work aims to expand these solutions, allowing them to cover a multiple-step water injection scheme, including falloff periods. When plugged into integrated Darcy’s Law, rate superposition plays a core role, providing an approximated analytical solution to predict the pressure derivative behavior during each injection step. This model can assess water and oil properties from pressure data using log-log plots. The analytical model was tested against a commercial finite-difference-based flow simulator, meeting expectations. This work lays the groundwork for the author’s future research on pressure behavior during water-alternating-gas (WAG) injection.