In the present, the infrastructure in the Rio Chama cannot withstand more than 1800 cfs. In order to keep the channel in better conditions, the U.S. Army Corps of Engineers sometimes lets down pulses of 1800 cfs. This helps the channel to not narrow as fast, but it is not enough. The Rio Chama is narrowing due to not receiving the high flows that it needs. In the past, the Rio Chama was able to withstand flows of over 4000 cfs, now that is not the case. The construction of Abiquiu dam started in the year 1956, and finalized in the year 1963. Looking at historic flow data from the USGS website, from 1961 to 1962, the peak discharge below Abiquiu was 1870 cfs. This flow was then lowered by the finalization of the construction of the dam, which shows why the peak discharge below Abiquiu from 1963 to 1964 was 1020 cfs. The peak discharge from 2017 to 2018 was 1130 cfs, which shows that the discharge has been significantly dropped since the building of the dam until now. These discharges are not enough to keep the channel in a good condition given that sediment will accumulate, and the floodplain will not flood, which will affect the condition of the riparian vegetation. The U.S. Army Corps of Engineers runs 1800 cfs down the river at certain times to keep the river from shrinking, but this discharge is not enough. If flows over 1800 cfs were let down, the diversions would most probably fail, and the floodplain would inundate.
In the hypothetical scenario that the diversions in the lower Rio Chama were to be consolidated and able to withstand 4000 cfs down the river, the river would be in a healthier condition than it is right now. Sediment would be able to be flushed down, and riparian habitat would be restored, but this would mean that flooding would need to happen. In order to keep the land dry in order to help not only with irrigation, but also to keep people’s feet dry, the maximum flow rate would need to also be between 1600 and 1800 cfs. It would also be necessary to let higher flows at certain times in order to restore vegetation, which means that flooding would still need to happen, but in a safe and controlled way. Some flooding would occur if the flow rates were about 2500 cfs, but it would not be as much as it would flood with the current conditions as can be show in the map found in the Ecological Restoration page, in the third figure. If the diversions were to be consolidated and maintained, the flood risk would be lowered and higher flow rates would be able to come down the lower Rio Chama without causing damage.
Right now there is not an alternative flow that could be proposed due to the poor conditions of the diversion structures. It is important to say that the pulse flows of 1600 to 1800 cfs have to keep being let down the lower Rio Chama, because if they do not, more sediment could accumulate. If the diversion structures were to be consolidated, it would be possible to have higher flows throughout the year, and maybe even higher pulses. It would be beneficial for the Rio Chama to have slightly higher flows throughout the year without putting people in danger of flooding. Consolidating the diversions structures is key to having a healthier Rio Chama. Slowly it would be possible to have a healthier ecosystem by increasing flow rates and not putting people in danger.