Completion Form

2023

The first stage of this project took place on 19-20 October 2022 and involved Tooele Army Depot (TEAD) and UDWR personnel. Work was more substantial on the downstream pond and required the pond to be drained prior to work being conducted. After an initial fish salvage, heavy equipment supplied and operated by TEAD was used to remove cattails and Phragmites and dredge this pond to create deeper open water habitat to provide refuge from potential low water conditions and improve longevity of the pond. Additionally, UDWR hand crews removed additional cattails from the center and edges of the upstream pond to limit the amount of disturbance to the Least Chub population which has historically been a slightly more abundant population than the downstream population. Heavy equipment was used in shallower water along the edge of the pond to grasp and pull larger clumps of cattail where it would not compromise the shoreline nor damage Least Chub habitat. Willow patches surrounding both ponds were selectively removed by heavy equipment to allow for more efficient access to the ponds for monitoring and management of the ponds. However, some patches were retained to provide some shading and also habitat for birds and mammals that utilize the area seasonally.
Additionally in 2022, TEAD furthered the restoration efforts after this initial stage by installing a pipe to convey water between the two ponds to limit overgrowth of vegetation and debris from clogging the previous channel. This will help to ensure a more effective method of conveying water to the lower pond and reducing the amount of maintenance needed to clear the previous ditch. During the process of deepening the downstream pond, the original clay liner was damaged. Previous to this, however, water levels typically declined to an undesirable degree when a consistent water supply was not provided. Therefore, a new pond liner was installed by TEAD in the downstream pond before filling occurred to ensure the pond's ability to hold water. A new dedicated water supply system would help ensure that consistent and healthy water levels are maintained.

During past annual monitoring at the Tooele Army Depot ponds, it became apparent that encroaching vegetation in both ponds was beginning to limit Least Chub habitat in the upper and lower ponds. Cattails (Typha sp.) in the lower pond had become overabundant to the point that no open water habitat remained and nonnative Phragmites had begun to grow in patches. Additionally, the lower pond had become shallow, providing reduced habitat for least chub in low water conditions. Relatively little open water was remaining in the upper pond. Willows surrounding both ponds had increased the difficulty in accessing the ponds both by UDWR personnel conducting surveys and TEAD personnel conducting maintenance activities.
On 13 September 2022, UDWR personnel met with TEAD to discuss and develop the project's goals and guidelines. Enhancing habitat for least chub, improving access to the ponds for monitoring and maintenance, and improving water supply security and conveyance efficiency between the two ponds were identified as high priority goals.
The first stage of this project took place on 19-20 October 2022 and involved Tooele Army Depot (TEAD) and UDWR personnel. Work was more substantial on the downstream pond and required the pond to be drained prior to work being conducted. After an initial fish salvage, heavy equipment supplied and operated by TEAD was used to remove cattails and nonnative Phragmites and dredge this pond to create deeper open water habitat to provide refuge from potential low water conditions and improve longevity of the pond. Additionally, UDWR hand crews removed additional cattails from the center and edges of the upstream pond to limit the amount of disturbance to the Least Chub population which has historically been a slightly more abundant population than the downstream population. The intent was to create a mosaic of deeper open water and open up some shallower, warmer habitat but still leave enough cattails to provide habitat for fish and invertebrates as forage. Heavy equipment was used in shallower water along the edge of the pond to grasp and pull larger clumps of cattail where it would not compromise the shoreline nor damage Least Chub habitat. Willow patches surrounding both ponds were selectively removed by heavy equipment to allow for more efficient access to the ponds for monitoring and management of the ponds. However, some willow patches, particularly the taller ones, were retained to provide some shading and also habitat for birds and mammals that utilize the area seasonally.
Additionally in 2022, TEAD furthered the restoration efforts after this initial stage by installing a pipe to convey water between the two ponds to limit overgrowth of vegetation and debris from clogging the previous channel. This will help to ensure a more effective method of conveying water to the lower pond and reducing the amount of maintenance needed to clear the previous ditch. During the process of deepening the downstream pond, the original clay liner was damaged. Therefore, a new pond liner was installed by TEAD in the downstream pond before filling occurred to ensure the pond's ability to hold water.

During UDWR annual monitoring of the least chub population, observations will be made of the growing extent of aquatic and terrestrial vegetation at each of the ponds and assessments made of the potential need and timing for additional maintenance. At these times there should also be some opportunity for limited, small-scale removal of emergent vegetation by hand in key areas. The next monitoring of the chub population is scheduled for 7 September 2023 and at that time the UDWR will also make an assessment of the aquatic and terrestrial vegetation approximately 10 months after the treatment. 
Water supply at this refuge site is intermittent and relies on uncertain availability. This issue is compounded by previous drought conditions making it difficult to supply adequate water to keep both ponds full, especially the lower pond. As part of the next phase of this project, UDWR has proposed an ESMF project (Tooele Army Depot Least Chub Ponds Water Supply System, No. 6556) to increase the reliability of the water supply. A buried pipe would be installed to connect the refuge ponds directly to the water source to continuously convey water to the ponds. This effort, scheduled for summer or fall of 2023, will increase the long-term security and management efficiency at these ponds. To help ensure that the new water supply functions properly and maintains adequate water levels for the Least Chub, a draft grant agreement is currently under development outlining the responsibilities of the UDWR and TEAD moving forward.

Keith Lawrence

08/29/2023 12:55:26