With the current rainfall pattern adding sufficient hydrology to the river system, flows downstream in the critical habitat have increased and are forecast to remain high. For this reason, the Bureau of Reclamation has scheduled a decrease in the release from Navajo Dam from 800 cubic feet per second (cfs) to 700 cfs for tomorrow, September 14th, at 4:00 AM.
Releases are made for the authorized purposes of the Navajo Unit, and to attempt to maintain a target base flow through the endangered fish critical habitat reach of the San Juan River (Farmington to Lake Powell). The San Juan River Basin Recovery Implementation Program recommends a target base flow of between 500 cfs and 1,000 cfs through the critical habitat area. The target base flow is calculated as the weekly average of gaged flows throughout the critical habitat area from Farmington to Lake Powell.
The historic 2013 flood in Colorado occurred over a week, Sept. 9-15, 2013, but the bulk of the more than 18 inches of rain in some locations occurred during a 30-hour period Sept. 11-12. An extremely moist, subtropical airmass ignited by a cold front parked over Colorado through much of the week, resulting in rainfall approaching totals that statistically would happen once every 500 to 1,000 years. Here’s a snapshot of one of Colorado’s most devastating natural disasters, including a lasting look at its impacts on Larimer County:
Nine fatalities, including two in Larimer County.
Around $4 billion in estimated damage (in 2023 dollars). Only the 1965 flood had higher damage estimates than the 2013 flood at around $5 billion (in 2023 dollars).
1,750 people rescued.
19,000 people evacuated.
2,006 homes destroyed.
26,000 homes damaged.
200 business destroyed.
750 businesses damaged.
200 miles of road damaged.
50 major bridges damaged.
15 counties included in a FEMA disaster declaration, from Larimer in the north to El Paso (Colorado Springs) in the south.
Rainfall records shattered during the 2013 flood
The heaviest rainfall totals of 12 to 18 inches were widespread through much of central Boulder County, stretching from Boulder north and west toward Jamestown, Lyons and into central Larimer County, including the Estes Park area.
The 24-hour state precipitation record was broken at the Fort Carson military base near Colorado Springs, with 11.85 inches of rain falling on Sept. 12.
Boulder set a calendar day all-time rainfall record of 9.08 inches and monthly record of 18.16 inches.
Click the link to read the article on The Denver Post website (Elise Schmelzer). Here’s an excerpt:
For decades, Dillon Reservoir has been a place where anglers could hook the fish of a lifetime — a 10-pound, 30-inch wild brown trout. But the brown trout population in one of Colorado’s most visible and accessible mountain reservoirs has declined in recent years, prompting state wildlife officials to consider stricter fishing regulations on the reservoir and seasonal closures on nearby waters. It’s unclear exactly what is causing the decline, said Jon Ewert, an aquatic biologist at Colorado Parks and Wildlife. But increased fishing during the pandemic, and after, may be a factor…
Other potential causes include a change in water quality, development along the rivers and streams where the trout spawn, and stress from higher water temperatures caused by drought, Ewert said…
The number of brown trout measuring more than 14 inches long has declined for four consecutive testing years, according to population surveys conducted by Colorado Parks and Wildlife. The agency conducts surveys every two years. In 2014, trout larger than that size made up 62% of all brown trout caught in the survey nets. By 2022, they made up only 33%…The brown trout in the Blue River upstream from the reservoir also have experienced an “obvious and significant decline,” according to a 2019 CPW report…
The proposed rules would require anglers to immediately release brown trout that are longer than 14 inches, with the rule applying to the reservoir, to sections of the Blue River south of the reservoir and to Tenmile Creek. Fishing would be banned entirely from Sept. 1 to Dec. 1 in two places where the trout spawn in the fall: the Blue River between the reservoir and three miles north of Breckenridge, and West Tenmile Creek from Copper Mountain to the reservoir.