A photograph from a canal lining manual shows the process of coating a ditch with oil to decrease water loss. This picture was taken in 1946 in Colorado.

Another major change during this period involved the transition from irrigation ditches to gutters to control water flow on the side of the roads.[127]  Cement gutters and oiled streets became the norm.[128]  As for the active irrigation canals, their outdated design was causing a great deal of water loss.[129]  It was becoming standard in the country for canals to be lined with cement, fabric and tar, or road oil.[130]  Of course such updates were expensive. One proposed solution was to install pipes to convey waters over long distances to the irrigation ditches.[131]  This action was taken in some locations, especially where “rubbish” was being dumped.[132]  The companies also found regular cleaning could decrease water loss and the installation of flumes in certain areas could bring the loss down from 60% to 10%.[133]  Only areas of highest potential water loss were lined with cement or clay.[134]  It was not until the 1960s that larger, more significant improvements would occur.