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1 reached it in the river (Mabey and Shiozawa 1993). The decline in razorback suckers and the near extirpation of the bonytail (G. elegans) in the upper basin may be linked directly to low or lack of larval survival in these species. Therefore, flooded bottomland habitats are important to some, if not all, of the endangered Colorado River fishes in the upper basin. Zooplankton produced in productive off-channel habitats such as flooded bottomlands also provide food of the proper quantity and size at the right time needed for larval survival of endangered fishes that occupy main channel habitats such as the Colorado squawfish and humpback chub (G. cypha). General 1 1 PROPOSED DEVELOPMENT/ACTION The CDPOR agreed to allow utilization of this site for habitat restoration by the Recovery Program. Because reclamation procedures related to former gravel mining activities are underway, it will be necessary to establish a written agreement with the State of Colorado specifying access conditions to the property during construction and fish inventory and biological monitoring. -Reclamation of the land is usually conducted in 5-year phases. Whitewater Building Materials Corporation is responsible for enacting reclamation procedures set forth in their permit granted by the Colorado State Mined Land Reclamation Board. The Whitewater Building Materials Corporation is concerned that activities related to the construction activity and followup biological monitoring of the pond will interfere and impair their ability to properly reclaim this site. If the proposed action is approved, it might be in the interest of the Recovery Program to recommend that Whitewater Building Materials Corporation be released from their immediate reclamation obligations at this site. Primary Development Specific Management/Research Objectives: 1. Determine the use of connected gravel-pit ponds as off-channel habitats during high water by adult Colorado squawfish and adult razorback sucker. 2. Compare the seasonal use of a graded vs. an ungraded pond connected to the river by non-native fishes and adult Colorado squawfish and adult razorback sucker. Because the river is threatening the dike that separates it from the larger pond, the decision was made to suspend back filling this pond. However, it is recommended that a portion of the dike at the downstream end be removed and a channel established to connect the pond with the river (Figure 4). The channel bed should be about 20-feet wide. The channel width and bank slope should be modeled similar to the channel connecting the river and drainage ditch that is immediately north of the proposed site. The water level in the pond would be self-regulating because no water or fish control structures would be installed, 13