in 1920, the tulsa mayor appointed a non-partisan water board. the board, in turn, hired j. h. trammell to perform as the engineering contractor to plan the spavinaw project, with w. r. holway as his assistant. trammell later left the firm and holway took over as project manager. trammel and holway found that the gravity flow process previously advocated by t. c. hughes was not only feasible, but could carry water as far as lake yahola, much closer to tulsa than hughes had estimated. the board then hired george w. goethals to review the plan and cost estimate. goethals assessed that both were feasible and practical, and that trammel's cost estimate of $6.8 million ($ in 2020) was adequate.