Late-September rains lift Bluewater Lake, send Rio San Jose sharply higher
CIBOLA COUNTY, N.M. – Weeks of late-monsoon rainfall are beginning to show more clearly in Cibola County's surface-water measurements.
Bluewater Lake rose slightly during the past week, while the Rio San Jose at Acoma Pueblo climbed substantially and briefly surged above 4 feet Monday night as another round of heavy rain moved across the county.
The increases come after repeated September storms saturated soils and produced flooding concerns across western New Mexico. They offer the clearest response yet in the two measurements regularly tracked by the Citizen, although neither a one-week increase nor a short-lived river surge means Cibola County's longer-term drought and water concerns are over.
Bluewater Lake
According to provisional U.S. Geological Survey data, Bluewater Lake stood at an elevation of 7,364.26 feet Tuesday morning, Sept. 29, up from 7,364.15 feet on Sept. 22.
That is an increase of 0.11 feet, reversing the weekly declines recorded through much of the summer.
The increase is relatively small, but its timing is notable following repeated September rainfall across the region.
Rio San Jose
The response on the Rio San Jose was much more pronounced.
The river at Acoma Pueblo measured 2.53 feet Tuesday morning, up 0.58 feet from a measurement of 1.95 feet on Sept. 22.
USGS data also captured a much larger, shortlived rise during Monday night's heavy rainfall. The river reached 4.32 feet at 10 p.m. Sept. 28 before falling to 2.53 feet by Tuesday morning.
That rapid rise and decline illustrate how quickly a stream can respond to heavy rainfall and runoff. The 4.32-foot reading should not be treated as the river's level for the entire week, but it provides an important snapshot of the response to Monday's storm. Arroyos can quickly fill and quickly empty.
Precipitation Across Cibola Rainfall over the past week
Cibola County entered the reporting period already wet.
A Flood Watch was in effect Sept. 22-23 as another surge of monsoon moisture brought the potential for rainfall rates of 1 to 2 inches per hour. The storms followed an already-wet stretch in western New Mexico, where saturated soils increased the amount of rainfall capable of becoming runoff.
The effects became particularly apparent as another storm reached the county Monday, Sept. 28. Steady and heavy rain led to reports of flooding and standing water, prompted road closures in Grants and led the city, Pueblo of Acoma and Pueblo of Laguna to make sandbags available. A roof leak was also reported at the historic Mother Whiteside Memorial Library building in Grants.
The water measurements now provide evidence of how at least part of that precipitation moved through the local system. The Rio San Jose's rapid rise Monday night shows a strong runoff response, while Bluewater Lake recorded its first weekly increase after an extended period of decline.
Higher in the Zuni/Bluewater River Basin, the NRCS Rice Park SNOTEL site reported 17 inches of water-year precipitation through Sept. 29, or 87% of the site's median of 19.6 inches. Water precipitation collapsed at this station in March. The station reported 0.2 inches of snow-water equivalent on Sept. 29.
SNOTEL data are provisional and represent conditions at the mountain station rather than Cibola County as a whole.
What to expect
More water may still be moving through the system.
The National Weather Service warned Monday that another moisture-rich storm system could bring roughly 1 to 3 inches of additional rainfall across the broader region through Wednesday, with isolated locations potentially receiving more. Cibola County, including Grants, was placed within a Moderate Risk for excessive rainfall as already-saturated soils increased the potential for rapid runoff.
That means this week's Tuesday morning measurements may not capture the full response to the ongoing storm.
Residents should continue to avoid flooded roads, arroyos and low-water crossings. With saturated ground, runoff can develop rapidly even where rain is not particularly heavy at the time.
Water data courtesy of the United States Geological Survey. Temperature, precipitation and drought information courtesy of Drought.gov, the National Weather Service, the U.S. Drought Monitor, the Climate Prediction Center and the New Mexico Environment Department.