MILLS, Wyo. – The U.S. Bureau of Reclamation has announced the annual fall drawdown of water levels in Alcova, Glendo and Guernsey reservoirs on the North Platte River has begun.

Water levels in Guernsey Reservoir were expected to start declining the morning of Sept. 9. Officials anticipate surface levels will drop 12 feet, to 4,400 feet surface elevation, by Sept. 17. After that date, drawdown at Guernsey will vary, based on timing and demand downstream of the reservoir, a release from Wyoming Area office in Mills stated.

Water level reductions in Alcova Reservoir near Casper is expected to begin Oct. 1. Through the month of October, surface elevation of the reservoir will decrease by about 10 feet at an approximate rate of four inches per day. 

Normal winter operating levels at Alcova Reservoir are between 5,487 and 5,489 feet. Water released in the drawdown will be restored downstream in Glendo Reservoir.

Levels at Glendo Reservoir are anticipated to continue to gradually decline, reaching a final seasonal surface elevation around 4,597 feet by Sept. 30. Final elevations at both reservoirs may change, depending on variations in water demand, the release said.

Boaters, recreationists and irrigators will need to take precautions and be aware of changing flows in the river between Glendo and Guernsey and the decreasing surface level in Guernsey.

Nebraska

The approaching end of the irrigation season means declining water levels across the region, as farm and ranch operations gear up for fall activities. The good news is topsoil moisture supplies in Nebraska remain 91 percent in the adequate to surplus range, with subsoil moisture at 92 percent adequate to surplus, according to the weekly U.S. Department of Agriculture progress report from the National Agriculture Statistical Service field office in Lincoln, Neb.

There were 5.1 days suitable for fieldwork during the week ending Sept. 15, according to the report. The state’s corn crop was ranked 71 percent good to excellent, with 97 percent in the dough stage, compared to 100 percent at this time last year and the 99 percent five-year average.

Corn in the dent stage was ranked at 82 percent, behind both last year’s 91 percent and the five-year average 90 percent. Mature corn was listed at 19 percent on the week, well behind the 41 percent reported last year at this time and the five-year average of 35 percent.

Winter wheat planted was 19 percent, equal to last year, and behind 26 average. Sorghum condition rated 1 percent very poor, 1 poor, 17 fair, 64 good, and 17 excellent.

Sorghum coloring was 84 percent, behind 90 last year and 91 average. Mature was 6 percent, well behind 26 last year, and behind 23 average.

Dry edible bean condition rated 10 percent very poor, 22 poor, 25 fair, 38 good, and 5 excellent. Dry edible beans dropping leaves was 61 percent. Harvested was 11 percent.

Pasture and range conditions across the state rated 1 percent very poor, 3 poor, 18 fair, 60 good, and 18 excellent.

Wyoming

Scattered thunderstorms across portions of Wyoming last week brought limited additions to mostly adequate irrigation and stock water supplies.

Irrigation water supplies were rated 17 percent fair and 83 percent good for the week ending Sept. 15, according to information from the U.S. Department of Agriculture National Agricultural Statistics Service field office in Cheyenne. Stock water supplies for the same period in Wyoming were rated 4 percent very short, 16 percent short and 80 percent adequate.

The U.S. drought monitor report, released on Sept. 12, showed most of Wyoming with good moisture, but with abnormally dry conditions in the western, southwestern and south-central parts of the state. Limited rainfall across southeastern portions of the state means potentially good seed beds for winter wheat, but producers said some replanting may be required, due to soil crusting in some places. The rain also means pastures are retaining some of their green.

In other areas of the state, one south-central Wyoming report indicated late summer conditions persist across the region, while the Laprele irrigation district season has ended for the year as producers anticipate the arrival of the average date of first frost. There were also reports of grasshopper damage in alfalfa and grass hay as well as rangeland in the south-central region.

There were 6.5 days suitable for field work on average across Wyoming last week. Alfalfa hay was rated 82 percent good to excellent, on pace with both the previous week and one year ago at this time. Corn was rated 76 percent good to excellent, consistent with the previous reporting period, but almost 10 points behind a year ago and the state’s five-year average.

Pasture and range land was ranked at just 41 percent good to excellent and 58 percent poor to fair, typical for this time of year. Livestock ranked 92 percent good to excellent condition, on pace with last week, last year and the five-year average.

Just short of half the state’s winter wheat crop – 40 percent – has been planted and 10 percent reported emergence. Ninety-five percent of alfalfa hay saw second cutting as of Sept. 15, with 33 percent reporting a third cutting had been harvested. Last year at this time, 100 percent of the second-cutting hay was harvested and 60 percent of third cutting crops were in.

Barley growers reported 87 percent of the state’s crop was harvested, behind the 96 percent both last year and on the five-year average.

Colorado

Isolated precipitation didn’t have much negative impact on harvest activities across the Centennial State last week, according to the weekly crops report from the NASS regional field office in Lakewood, Colo. 

Frost put an end to the growing season in some northwestern counties last week, but cool-season grasses were reportedly still growing where there was sufficient moisture.

With 6.3 days suitable for fieldwork across the state last week, harvest activities picked up significantly, where conditions allowed. Reporters noted rain was enough to delay the start of corn silage harvest for some producers. 

More producers also began seeding winter wheat last week. Hail severe enough to damage crops was reported in a couple northeastern counties. 

Received moisture was beneficial for pasture and rangeland conditions, with some dry pockets remaining. Scattered moisture was received in southwestern counties last week, but overall conditions remained dry. According to the latest U.S. Drought Monitor report, abnormally dry to moderate drought conditions expanded in southwestern counties. 

In the San Luis Valley, barley harvest was virtually complete and potato harvest reportedly made good progress. Third cutting of alfalfa also began. A reporter noted livestock producers were moving stock out of the mountains into lower pastures in some areas. 

In southeastern counties, a reporter noted portions of north central Bent and Prowers counties received very heavy rainfall last week along with small hail. Rain in the area greatly benefitted crops that were in need of rain. Hay harvest continued but was slow. 

Statewide, stored feed supplies were rated 5 percent short, 78 percent adequate, and 17 percent surplus. Sheep death loss was 2 percent heavy, 63 percent average, and 35 percent light. Cattle death loss was 74 percent average and 26 percent light.