The Colorado Water Conservation Board (CWCB) monitors streamflow to ensure decreed instream flow (ISF) water rights are protected. If streamflow drops lower than the amount decreed to an ISF water right, and that right is in priority, staff may place an administrative call for water. The following table summarizes recent instream flow calls placed.
| Water Division | Stream Name | Case Number | Date of Formal Written Call |
|---|---|---|---|
4 | Uncompahgre River | 98CW0222 | September 30, 2024 |
4 | Slate River | 80CW0092 | September 18, 2024 |
6 | Elk River | 77W1279 77W1331 | September 4, 2024 |
6 | Slater Creek | 17CW3030 | September 4, 2024 |
6 | Bear River | 77W1315 | August 13, 2024 |
4 | Dallas Creek | 98CW0234 | May 13, 2024 |
| 5 | Eagle River | 78W3811 | September 20, 2023 |
| 5 | Beaver Creek | 75W2719 | September 20, 2023 |
| 4 | Slate River | 80CW0092 | September 12 2023 |
| 6 | Elk River | 77W1279 | September 1 2023 |
| 3 | Bear Creek | 84CW0141 | August 31, 2023 |
| 5 | Colorado River | 80CW0447 | October 22,2022 |
| 5 | Beaver Creek | 75W2719 | September 9, 2022 |
| 5 | Eagle River | 80CW0126 80CW0134 | September 9, 2022 |
| 4 | Slate River | 80CW0092 | September 2, 2022 |
| 6 | Elk River | 77W1279 | August 26, 2022 |
| 5 | Roaring Fork River | 76W2948 | August 22, 2022 |
| 5 | Crystal River | 75W2721 75W2720 | September 1, 2021 |
| 5 | Crystal River | 75W2721 75W2720 | August 10, 2021 |
| 4 | Slate River | 80CW92 | August 17, 2021 |
| 6 | Slater River | 17CW3030 | August 15, 2021 |
| 5 | Roaring Fork River | 76W2948 | August 12, 2021 |
| 5 | Beaver Creek | 75W3795 | August 5,2021 |
| 5 | Colorado River | 80CW447 | October 22, 2020 |
| 5 | Roaring Fork River | 76W2948 | September 30, 2020 |
| 5 | Eagle River | 80CW126 80CW134 | August 24, 2020 |
| 5 | Crystal River | 75W2720 | August 20, 2020 |
| 3 | South Fork Rio Grande | 84CW163 | August 18, 2020 |
| 5 | Hunter Creek | Various | August 12, 2020 |
| 5 | Beaver Creek | 75W2719 | August 12, 2020 |
| 4 | Washington Gulch | 10CW180 | August 11, 2020 |
| 6 | Elk River | 77W1279 77W1331 | August 7, 2020 |
| 4 | Slate River | 80CW92 | August 3, 2020 |
| 4 | Dallas Creek | 98CW0234 | June 15, 2020 |
| 4 | Slate River | 80CW0092 | September 16, 2019 |
| 4 | Dallas Creek | 98CW0234 | September 6, 2019 |
| 6 | Elk River | 77W1279 77W1331 | September 4, 2019 |
| 5 | Beaver Creek | 75W2719 | August 15, 2019 |
| 5 | Colorado River | 80CW0447 | November 9, 2018 |
| 2 | North Fork South Arkansas River | 77W4659 | October 19, 2018 |
| 5 | Piney River | 86CW0229 | September 19, 2018 |
| 5 | Blue River | 86CW0217 | September 14, 2018 |
| 5 | Eagle River | 80CW0124 80CW0126 | August 9, 2018 |
| 5 | Beaver Creek | 75W2719 | August 9, 2018 |
| 5 | Roaring Fork River | 76W2948 | August 9, 2018 |
| 5 | Eagle River | 78W3811 | August 8, 2018 |
| 6 | Elk River | 77W1279 77W1331 | August 8, 2018 |
| 5 | Crystal River | 75W2720 | August 3, 2018 |
| 7 | San Juan River | 80CW0040 | August 2, 2018 |
| 4 | Slate River | 80CW0092 | July 19, 2018 |
| 5 | Hunter Creek | Various | July 19, 2018 |
| 2 | Cottonwood Creek | 79CW0115 | July 5, 2018 |
| 5 | Colorado River | 80CW0447 | November 30, 2017 |
| 5 | Beaver Creek | 75W2719 | September 7, 2017 |
| 5 | Cross Creek | 78W3795 | September 7, 2017 |
| 4 | Dallas Creek | 98CW0234 | September 7, 2017 |
| 4 | Slate River | 80CW0092 | September 7, 2017 |
| 6 | Elk River | 77W1279 77W1331 | August 31, 2017 |
| 5 | Crystal River | 75CW2720 | August 29, 2017 |
| 5 | Eagle River | 78W3811 | August 29, 2017 |
| 5 | Fryingpan River | 73W1955 | August 29, 2017 |
| 1 | South St. Vrain Creek | 78W9362 | October 24, 2016 |
| 7 | Dolores River | 75W1346 | October 4, 2016 |
| 5 | Colorado River | 80CW0447 | October 3, 2016 |
| 4 | Slate River | 80CW0092 | September 16, 2016 |
| 5 | Eagle River | 77W3811 | September 8, 2016 |
| 5 | Crystal River | 77W2720 | August 31, 2016 |
| 6 | Elk River | 77W1279 77W1331 | August 17, 2016 |
| 5 | Roaring Fork River | 76W2948 | March 25, 2016 |
| 5 | St. Louis Creek | 90CW317 | November, 2015 |
| 5 | Colorado River | 80CW447 | November 13, 2015 |
| 4 | Slate River | 80CW092 | October 16, 2015 |
| 6 | Elk River | 77W1279 77W1331 | September 2, 2015 |