This interesting map was originally published in an 1877 San Francisco Municipal Report, which concentrated primarily on the never-ending challenge of bringing water to the expanding population. It plots seven distributing reservoirs within the city, giving their depths, elevations, and supply capacities.
What makes the map especially compelling is that it delineates specifically which areas of the city are supplied by which reservoir, a feature we are unaware of on other maps. The mapmaker has used a simple color scheme to illustrate the limits of each district. Almost the entirety of SOMA is supplied by the College Hill reservoir, except for a small patch of Rincon Hill still supplied by Laguna Honda.