Todd,

The protocol inventories every visible redd between a point upstream of Bacon Ck downstream nearly to Rockport. Since very few, if any, mainstem spawners spawn in less than 0.5' of water, it's unlikely that even one April steelhead redd was dewatered. Are you saying you observed multiple redds dewatered by the May flow reductioin? I'll try to check with Dave and Stan this week and see what the records indicate.

The flow drop in May was due to anticipated spring runoff beginning that month that would increase the gage height at Marblemount. Had SCL not run higher than normal flows during March and April, more likely than not the project would have gone into uncontrolled spill in May with the onset of spring runoff, resulting in the peak spawning occurring at high flow such that subsequent incubation flows couldn't be sustained through the fry emergence period. Each year the flow committee weighs the water supply with the forecast and tries to schedule a flow regime to maximize survival. While perfection is hard to hit, it's pretty easy to improve on the natural regime of high spring runoff flows during the peak of spawning, and the natural rate of redd dewatering that occurs after the runoff, but prior to peak emergence.

Smalma,

The question of decreasing spawning in the Marb-Rock reach remains unanswered. The basin-wide redd counts are generally down the last 15 years, which seems tied to the reduced marine survival. The disproportionate reductiion in the Marb-Rock reach doesn't jive with the flow management measures that should facilitate higher egg to fry survival than say the impressive Sauk Darr-Benn reach. We've yet to examine any variables that may be affecting other life history stages, since flows so dramatically affect the spawning to emergence stage.

Generally, over winter survival of juvenile steelhead should benefit from the same flow measures used to protect chum salmon spawning and incubation. That doesn't mean that it does, but intuitively it seems like it should. Aquatic invertebrates are affected by hydro flow fluctuations as documented by the Skagit studies of the 70s and others. No invertebrate studies of consequence have examined the most recent flow agreement, but all parties to the discussion have felt that significant reductions in flow fluctuations should benefit invertebrates as well. The point is noted, however, that the invert. population is most likely less dense and robust as on the unregulated tributaries.

I agree about the complexity of ecosystems, and I freely acknowledge that it's complex enough to prevent me, you, and others from having figured this out yet. The flow program is not intended to favor one species over another. If you examine the flow agreement, the protection levels are expected to exceed 98% for all affected species, except chum in the event of a cold spell that coincides with peak chum spawning, which is why SCL funded all the off-channel chum habitat projects.

There are resource costs to the decisions made every day. The flow agreement was intended as a decision that provides resource benefits instead of costs. That's not to say there haven't been unintended costs, however.

Sincerely,

Salmo g.