By early afternoon, the secondary channel through the center of the dam was nearly as wide as the original eastern flow path, and the total water throughput of the obstruction had reached approximately eighty percent of the pre-collapse channel capacity. The upstream water level had returned to within one centimeter of its normal pre-collapse height, and the silt plume entering the basin had thinned from its peak opacity to a faint haze that the basin's natural circulation was already beginning to disperse.
Zephyr made three complete circuits of the obstruction site in the hour following the breakthrough, monitoring the structural stability of the remaining dam material and tracking the rate at which the two flow channels were continuing to widen. The clay mass was still dissolving, but at a rate that the basin could now absorb comfortably. The acute crisis was over.
He signaled the dissolution of the coalition with a specific aerial display — three wide clockwise circles at decreasing altitude, a pattern that the water striders and mayflies recognized as the all-clear call from their two seasons of experience with Zephyr's signals. The diving beetles received the signal secondhand through the water strider colony and began dispersing to their normal oxygen-gathering circuit routes within minutes.
The return flight to the basin took Zephyr along the full length of the affected channel, giving him a detailed assessment of the silt distribution along the bed. The eastern channel, which had carried the full flow during the obstruction period, had scoured clean — the gravel bed was exposed and pale, with no silt deposit.
The main channel bed below the obstruction showed light silt coverage over a length of about eight meters, thinning rapidly downstream. The basin inlet showed the heaviest deposit, a thin layer of pale clay silt over the dark organic basin mud, but the layer was too thin to significantly impede the root zone circulation of the water lilies.
The basin itself was recovering visibly. The water surface, which had been a uniform pale brown-grey at the peak of the silt influx, was now clearing from the outlet end toward the inlet, the natural circulation of the basin carrying the suspended particles toward the outlet and out into the main downstream channel.
The diving beetles had resumed their full-depth oxygen cycling, surfacing and diving with the regularity that indicated normal dissolved oxygen levels. The water strider colony had spread back to its full feeding distribution across the basin surface.
Three mayflies were dancing above the lily pads again in the afternoon light, their wings catching the sun in brief sparkles of transparency as they turned in their spiraling flight. The water lilies sat placid and unmoved on the surface, their white flowers open to the afternoon, their root systems drawing undisturbed oxygen from the water below.
Zephyr settled on the flat boulder at the basin's eastern outlet and folded his wings, reading the air of the recovering river with the full surface of his iridescent membranes. The current moving past the boulder was clean, clear, and carrying the correct mineral signature of healthy river water. The basin was whole.
The twelve-minute post-breakthrough assessment that Zephyr conducted from the eastern outcrop above the dam site documented the debris flow distribution with the systematic coverage he applied to all significant river events. He flew a grid pattern above the affected channel section, reading the turbulence pattern above each grid square and recording the silt distribution information through his wing sensors.
The result was a complete post-event map of the channel that he would use to direct any additional maintenance operations required in the coming days.
The data from the survey was encouraging. The breakthrough had produced a clean, straight-edged new channel that was already self-maintaining under the current flow — the water was scouring the channel bottom naturally, and the clay faces on either side of the opening were stable rather than continuing to collapse.
The risk of secondary dam failure on either side of the new channel was low. The remaining material would dissolve gradually and predictably.
The downstream silt distribution showed a progressive reduction in concentration that was consistent with natural dispersion rather than continued active silt loading. The basin's inlet was receiving significantly cleaner water already, and the basin circulation system was beginning to move the deposited silt toward the outlet in the normal way.
Zephyr estimated that the basin would be at normal water clarity within six hours, and the thin bed silt layer would have been incorporated into the normal bottom substrate within four days.
He made three final passes above the water strider and diving beetle work areas to signal the completion of operations and the stand-down of the emergency coordination structure. The water striders responded immediately, their colony spreading back toward the basin in their normal travel formation. The diving beetles surfaced, took extended air loads, and descended again — the behavioral pattern of individuals transitioning from task-focused work to routine territory activity.