Moist Soil Unit Plan for Fall/Winter 2024-2025

Cibola National Wildlife Refuge manages eight moist soil units (MSU) within the Island Unit on the Refuge.  MSUs are traditionally flooded up during the fall for waterfowl forage and roosting habitat and held through the winter.  Flooding of units is staggered to manage seed and vegetation forage early in the season. Depths are managed to recruit invertebrate forage later in the season as waterfowl prepare for their return migration.

Cibola NWR floods these units by pumping water from the Colorado River to the units via concrete and earthen ditches.  During the 2023/2024 migration, the refuge experienced infrastructure failures that prevented the consistent flooding of most of our MSUs.  The Refuge worked with the Bureau of Reclamation to replace the pumps for the Island Unit in the Spring of this year.  We are continuing our work to repair canals and gates to ensure water delivery to our habitats for the upcoming season.

One of the most challenging factors for water delivery across the refuge is the depth of the Colorado River, as the function of our pumps depends on a minimum river level and flow (cubic feet per second) which is managed by the Bureau of Reclamation and Palo Verde Irrigation District. If river levels fall below this minimum level, the refuge cannot draw water from the river and therefore cannot maintain water levels in the MSUs.  Additionally, migration of sandbars along the river impacts the operation of the pumps and flooding of units.  Sandbars cause the pumps to bring up significant sediment that settles out in the irrigation canals and must be cleaned out regularly, during which pumps cannot be operated.  There is currently a sandbar that has enveloped the intake pipe for our Island Unit pumps and has restricted our ability to flood marsh bird and shorebird habitat on the Refuge. 

Refuge staff have outlined the following goals for each of the units for the 2024/2025 season.  Understanding the objectives and challenges discussed above, the Refuge may not be able to achieve the following schedule and hunt quality may be negatively affected.  As we proceed through the season, updated information will be available on the refuge website and social media.

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