Upon the General’s map each blue and red channel bore a figure for its capacity in thousands of cubic feet per second. Above Colusa the river could carry 155 and the by-pass 120. But at Colusa Weir the river, if it was necessary, spilled 87 into the by-pass, for its own capacity was reduced to 66 and that of the by-pass rose proportionately. Lower down, the dimensions of the whole system grew larger. Below Sacramento the river carried 110 and the by-pass, miles wide between its levees, carried 490.

If the discharge rose above this maximum of 600,000 cubic feet per second, theoretically the condition of ’61 would be repeated and an area the size of Massachusetts would be under water. In actuality a flooding of one part of the valley would probably save the rest, unless the conditions should be too long continued. Time, as the General knew well, was often a deciding factor. It might even be possible, in a sense, for the maximum to be exceeded without any general break, because the crest from each branch of the river might pass at different times. Thus high water from the American usually went by before the crest arrived from the Feather and its tributaries, and that in turn was out of the way before the flood from the upper Sacramento rose to full height. But if time under some conditions was a help it could also cause disaster. A sudden cloudburst in one drainage basin might bring down a crest which would top the levees locally while elsewhere in the system the channels were far below capacity.

Sometimes the newspapers referred to the General as “The Czar of the River.” As a military man, the General loved command well enough not to resent the title, but he knew that his authority was not very effective. The planning and construction of the vast levee-system had to be done months and years in advance, and once the rain started falling, even a Czar was little more than a spectator.

In his office during each storm he collected data upon actual rainfall; he co-ordinated this with the Weather Bureau forecasts; he estimated the advance of the crests of various streams by reports of the readings of numerous river-gauges. From all these data he predicted the hour at which water would begin to spill over the various weirs, and the area which this water would cover. Then he sent out warnings. The broad lands of the by-passes pastured thousands of sheep and cattle; in some places certain crops could even be grown. At the General’s word the sheep and cattle were hurriedly collected and driven to safe places; the roads across the by-pass lands were closed; men began to patrol the levees to guard against breaks and seepage; and all the river towns passed into what was almost a state of siege.