This is a service / maintenance or supply contract in Madison, Wisconsin. Contact the soliciting agency for additional information.

All referenced figures can be found in the attached Narrative file, found in the supplementary documents section. Mississippi River backwaters within Pool 6 are currently a high priority resource for WI DNR due to a general lack of deep, backwater habitat within the pool (Figure 2). Recent flood and high discharge conditions have resulted in declining water quality conditions due to an influx of channel sand into the main inlet to the complex. The channel inlet at RM 624.5 is currently blocked by sediment during normal and low flow conditions. This channel flows under a bridge into the middle of the complex during above normal river stages and can have a positive influence on WQ conditions in deeper water located along the tracks in the lower portion of the complex when flow is present. However, reduced flow delivery to the system results in periods when winter water quality conditions are outside temperature and dissolved oxygen ranges required for overwintering backwater fish communities. Recent surveys conducted under near-median discharge conditions indicated widespread hypoxia in the complex (Figure 3). Fish kills in Sam Gordy's Slough are likely to occur in the coming years if no action is taken. Water Quality monitoring conducted by the WI DNR identifies hydraulic connectivity as the primary water quality driver in Sam Gordy's Slough. A detailed rating curve has been developed for inflows into Sam Gordy's Slough (Figure 4). When main channel water input to the slough is low, dissolved oxygen declines precipitously. A low-cost project to optimize multi-season connectivity (summer and winter) will produce substantial water quality and ecological benefits within this complex. Questions from vendors are due February 28, 2025 at 4:30 PM