Casper-Alcova Irrigation District hired WLC to prepare contract documents and provide construction services to rehabilitate four concrete drop structures on the Johnson Lateral. These structures were constructed around 1940 and were showing signs of deterioration that required immediate attention to correct severe concrete spalling, cracks, exposed rebar, and leaning sidewalls. The rehabilitation design included installation of a 4” perforated drain behind each side wall, removal and replacement of spalled concrete, and sealing of cracks. All of this work was performed during the winter, to avoid interfering with irrigation season, which created a challenge for the contractor when installing new concrete. Rehabilitation of the structures increased the life of the structures and reduced the need for replacement.