Declining water level and filling by submerged vegetation and peat has substantially reduced open water habitat for least chub in East Pond (0.25 acres). Many areas are now only inches deep. There appears to be only one small area of the pond, measuring about 10x6 feet, where depth is over two feet. This pond has historically been a stronghold for one of only several remaining natural populations in the Central Region. It is also the only waterbody at Mills Meadows WMA lacking mosquitofish, an invasive species that has had huge impacts to least chub, including at this WMA. Manual removal of some of this accumulating vegetation and peat in at least a portion of the pond should help ensure least chub persistence by creating more open water habitat and reducing the amount of decaying organic matter, which may impact oxygen levels at certain times. Peatlands, such as those scattered throughout the WMA, are important and natural components of certain ecosystems and can have multiple benefits to water quality. However, left unchecked, ponds such as East Pond will eventually fill in and become peat bogs, rendering them unfit for occupancy by least chub.

Left unchecked, the pond will eventually fill in to the point where there is only scant water coverage and least chub have very little space, and of relatively poor quality, to occupy. Until a water right is obtained the pond cannot be legally dredged; therefore, a manual approach without the use of heavy equipment is necessary to begin reversing the filling trend. Longer droughts exacerbated by climate change increase the potential that that trend will continue and likely worsen in the coming years.

Utah Wildlife Action Plan. 2015. Least Chub are listed as a Species of Greatest Conservation Need (S2/N1) under the WAP. Severity of threats to its persistence include worsening droughts due to climate change (very high), water use and management (high) and invasive species (very high). Least Chub are particularly sensitive because they exist largely as isolated populations with shrinking habitat due to droughts, water management, and encroachment of vegetation on their habitat. Conservation Agreement and Strategy for Least Chub. 1998. Goal is to ensure long-term persistence of Least Chub within its historic range and support development of statewide conservation efforts. Objectives include to: 1) eliminate or significantly reduce threats to least chub and its habitat to the greatest extent possible, and 2) restore and maintain a minimum number of populations throughout its historic range that will ensure the continued existence of Least Chub. The CAS's goal and both objectives are applicable to the proposed project.

Working to help prevent the eventual conversion of open water to peatland could reduce the susceptibility of the landscape in the WMA to wildfire spread, however, this is a very long term projection and due to the relatively small size of the pond, unlikely to be signficant.

Manual removal of submerged vegetation and peat in the pond should help improve water quality by reducing the amount of decaying organic material in the pond, which increases biological oxygen demand and could therefore reduce dissolved oxygen levels during certain periods. Impacts to oxygen levels may be seasonal, such as during winter when the pond may freeze and oxygen exchange and circulation is more limited; and daily, such as during the night when plant respiration far exceeds photosynthesis. Proposed actions are not intended or expected to improve water quantity because only plants and saturated organic material (peat), and not sediment, are slated for removal. Dredging of the pond is not permissible due to infringement upon locally held water rights. The DWR does not have any water rights at the WMA.

Not applicable.

The sustainable use in question is occupancy by a native fish species; in this case listed as a Species of Greatest Conservation Need under the Utah Wildlife Action Plan. The proposed project is intended to increase and improve the amount of deeper, open water habitat so that this beneficial use can be sustained.