<html><head></head><body><div class="ydpbea88172yahoo-style-wrap" style="font-family:garamond, new york, times, serif;font-size:16px;"><div><div dir="ltr" data-setdir="false"><div id="ydp2a5373b9main" class="ydp2a5373b9site-main">
<div class="ydp2a5373b9full-container">
<div id="ydp2a5373b9primary" class="ydp2a5373b9content-area">
<div id="ydp2a5373b9content" class="ydp2a5373b9site-content">
<div class="ydp2a5373b9entry-main" dir="ltr" data-setdir="false">
<h1 class="ydp2a5373b9entry-title">This is the subject of the Hoopa Valley Tribe's motion for a Preliminary Injunction. See link to the final report.</h1><div><br></div><h1 class="ydp2a5373b9entry-title"><a href="https://www.trrp.net/restoration/flows/winter-flow-variability/" rel="nofollow" target="_blank">https://www.trrp.net/restoration/flows/winter-flow-variability/</a></h1><h1 class="ydp2a5373b9entry-title">Winter Flow Variability</h1>
<div class="ydp2a5373b9entry-content">
<p><i>Updated February 14, 2022.</i></p>
<p>Thank you to all who provided input on our Draft Trinity River Winter
Flow Variability Environmental Assessment. Your input has been helpful
in our effort to understand implications of the proposed action and to
analyze potential impacts of the recommended flow change. Reclamation
did not implement the winter flow regime in water year 2022 but the TRRP
is exploring our options for water year 2023. Our winter flow analyses
are now available in report format <a href="https://www.trrp.net/library/document/?id=2566" rel="nofollow" target="_blank">at the TRRP DataPort</a>. </p>
<div id="ydp2a5373b9attachment_3610" style="width: 370px" class="ydp2a5373b9wp-caption ydp2a5373b9alignright"><a class="ydp2a5373b9trrp-lightbox ydp2a5373b9cboxElement" href="https://www.trrp.net/wordterrain/wp-content/uploads/2021/05/WinterVariabilityProposal_LewistonDam.jpg" title="Photo of water being released from Lewiston Dam." rel="nofollow" target="_blank"><img class="ydp2a5373b9wp-image-3610" src="https://www.trrp.net/wordterrain/wp-content/uploads/2021/05/WinterVariabilityProposal_LewistonDam.jpg" alt="Photo of water being released from Lewiston Dam." style="width: 360px; max-width: 544px;" data-inlineimagemanipulating="true" data-id="1671567888859" draggable="false"></a><p id="ydp2a5373b9caption-attachment-3610" class="ydp2a5373b9wp-caption-text">Photo 1. Trinity River release from Lewiston Dam (photo by TRRP)</p></div>
<h5 style="color: #167ac6;">Project Background</h5>
<p>Following the 2000 Record of Decision (ROD), the U.S. Department of
Interior (DOI) established TRRP to restore the fisheries of the Trinity
River affected by dam construction and related diversions of the <a href="https://www.usbr.gov/mp/cvp/" rel="nofollow" target="_blank">Trinity River Division of the Central Valley Project<sup>1</sup></a>.
The Trinity River has also been impacted by past mining and timber
harvest activities in the watershed, and these conditions are
collectively addressed as well through TRRP’s restoration efforts.</p>
<ul style="list-style-type: none;"><li><sup>1</sup> <a href="https://www.usbr.gov/mp/cvp/" rel="nofollow" target="_blank">https://www.usbr.gov/mp/cvp/</a></li></ul>
<p>Administered by the U.S. Bureau of Reclamation (Reclamation), the
TRRP is a partnership of federal and state resource agencies, Tribes,
and Trinity County. The Program works to restore the processes and
attributes of an ecologically functioning river system, which should, in
turn, recover diminished salmon and steelhead populations while
retaining Trinity and Lewiston Dams’ deliveries of water and power to
California’s Central Valley.</p>
<p>There are five primary components of TRRP’s river restoration work:</p>
<ol><li style="margin-bottom: 0.5em;"><span style="font-weight: bold; font-style: italic; color: #008e4a;">Variable annual instream flows:</span> releasing water from Lewiston Dam, based on the water year type<sup>2</sup>,
to mimic natural Trinity River flows and interact with downstream areas
to enhance conditions for all life stages of fish and wildlife. These
variable annual instream flows are also sometimes called “restoration
releases”.
<ul style="list-style-type: none;"><li><sup>2</sup> TRRP uses five water year types to determine how much
water will be available to the Trinity River each year. The five water
year types are: Critically Dry, Dry, Normal, Wet, and Extremely Wet. A
wetter water year means more water is available for restoration flow
releases.</li></ul>
</li><li style="margin-bottom: 0.5em;"><span style="font-weight: bold; font-style: italic; color: #008e4a;">Channel rehabilitation:</span> restoring the functional floodplain of the river, which has been channelized and simplified by managed river flows and mining.</li><li style="margin-bottom: 0.5em;"><span style="font-weight: bold; font-style: italic; color: #008e4a;">Sediment management:</span>
reintroducing gravel (aka coarse sediment) to the river. Gravel
provides spawning areas for salmon and provides other habitat benefits.
Gravel entering the river system upstream of the dam is blocked from
being transported to the Trinity River below Lewiston Dam, creating a
gravel deficit in the river over time. TRRP resupplies the river with
gravel to make up for the dam’s impact in blocking new gravel supplies
that would otherwise be provided naturally.</li><li style="margin-bottom: 0.5em;"><span style="font-weight: bold; font-style: italic; color: #008e4a;">Watershed restoration:</span>
addressing negative impacts that have resulted from poor land
management in the basin. Watershed restoration activities include
decreasing the input of fine sediment from Trinity River tributaries
that can clog spawning gravels and fill deep areas of the river.</li><li style="margin-bottom: 0.5em;"><span style="font-weight: bold; font-style: italic; color: #008e4a;">Adaptive management:</span> monitoring, evaluating, and improving the effectiveness of river restoration actions.</li></ol>
<p>The TRRP is exploring changes toward how variable annual instream
flows are managed (Primary TRRP Component #1) with existing ROD water
from Lewiston Dam. Since the implementation of the ROD, variable flow
releases (aka restoration releases) have occurred after the water year
type is determined in mid-April<sup>3</sup>. An approved hydrograph
(i.e. water release schedule) developed by TRRP determines how much
water is released daily during this period of elevated flows. Variable
releases typically extend to early summer before returning to baseflow
conditions and then remain at baseflow until the following April when a
new water year is determined.</p>
<ul style="list-style-type: none;"><li><sup>3</sup> The water year type is determined by the Department of Water Resources’ B120 (ca.gov) water supply forecast.</li></ul>
<div id="ydp2a5373b9attachment_3609" style="width: 410px" class="ydp2a5373b9wp-caption ydp2a5373b9alignright"><a class="ydp2a5373b9trrp-lightbox ydp2a5373b9cboxElement" href="https://www.trrp.net/wordterrain/wp-content/uploads/2021/05/WinterVariabilityProposal_Juveniles.jpg" title="Underwater photo of juvenile salmon." rel="nofollow" target="_blank"><img class="ydp2a5373b9wp-image-3609" src="https://www.trrp.net/wordterrain/wp-content/uploads/2021/05/WinterVariabilityProposal_Juveniles.jpg" alt="Underwater photo of juvenile salmon." data-inlineimagemanipulating="true" style="width: 400px; max-width: 589px;" draggable="false"></a><p id="ydp2a5373b9caption-attachment-3609" class="ydp2a5373b9wp-caption-text">Photo 2. Young salmon on the Trinity River (photo credit Yurok Tribe Fisheries Department)</p></div>
<p>The current approach to implementing variable flows in the Trinity
River results in cold water releases from Lewiston Dam that are out of
sync from when the pre-dam Trinity River would have naturally received
seasonal peak flows. Undammed tributaries to the Trinity River naturally
flow higher during winter storm events, and as high elevation snowpack
melts in early spring. Thus, natural contributions to the Trinity River
from its tributaries are often receding by the time ROD flow releases
from Lewiston Dam occur after mid-April.</p>
<p>The asynchrony between flow management and the natural variability of
pre-dam flows has cascading impacts on the river’s form and ecology,
and perhaps the most detrimental of the impacts is to young salmon.
Pacific salmon’s life history has adapted to the natural seasonal
variability of flows for millions of years. Current flow management
keeps river conditions unnaturally cold, which suppresses metabolic
rates during the key period of growth for young salmon. Later in the
spring, the unnaturally cold river delays environmental cues that
trigger smolts to outmigrate to the ocean before conditions in the lower
Klamath become too warm to support salmon migration.</p>
<h5 style="color: #167ac6;">Winter Flow Variability Goals and Objectives</h5>
<p>The purpose and need for winter flow variability is to refine the
timing of restoration flows using the principle of AEAM to better meet
geomorphic, fish habitat, and temperature objectives of the ROD. Moving a
portion of the ROD volume released from Lewiston Dam to the winter
period is intended to have the following benefits to the natural
character of the Trinity River:</p>
<ul><li>Time restoration releases from Lewiston Dam to better match natural
flow variability during winter and spring runoff events. Coinciding
natural flows and Lewiston dam releases would enhance natural cleaning
and transport of river gravels.</li><li>Limit the impact that cold water from the dam has on the growth of
juvenile salmon by shifting a portion of ROD water from Lewiston Dam to
the winter period.</li><li>Allow the river to naturally warm earlier in the season than
currently occurs to provide the environmental cues smolts rely upon in
timing their outmigration to the ocean.</li><li>Provide elevated flows before salmon fry emergence to increase food
availability and higher river levels after emergence to increase access
to floodplain nursery habitats</li><li>Move ROD water allocations earlier to maintain more consistent lake levels in Trinity Reservoir through the summer months.</li></ul>
<h5 style="color: #167ac6;">Description of Potential Winter Flow Variability Actions</h5>
<p>Shift a portion of the ROD water for release during the winter to two
distinct periods termed the Flow Synchronization Period and the
Elevated Baseflow Period (Figure 1).</p>
<p><span style="font-weight: bold; font-style: italic; color: #008e4a;">Flow Synchronization Period:</span>
Between December 15 and February 15, ROD water equivalent to
60,000-acre-feet would be released from Lewiston Dam when forecasting
tools at downstream gages anticipate a rise in river levels of 4,500 to
12,000 cubic feet per second (cfs). The maximum scheduled flow from
Lewiston Dam during this period would not exceed 6,500 cfs. The optimal
combination of natural and dam-regulated flows to the Trinity River
resulting from this flow synchronization would be adjusted downward, as
necessary, to prevent flooding or damage to downstream properties.</p>
<p><span style="font-weight: bold; font-style: italic; color: #008e4a;">Elevated Baseflow Period:</span>
Between February 15 and April 15, ROD water would be released from
Lewiston Dam based on the Department of Water Resource’s B120 water
supply forecast. Using the B120 would prevent the overuse of ROD water
should the water year end up being drier than expected. During this
period, a hydrograph would be developed by TRRP to schedule the elevated
baseflow releases.</p>
<p>After April 15, the remaining ROD water would be released to the
Trinity River using the same methodology that currently exists for the
scheduling of restoration flows. No changes to summer baseflow (450 cfs)
or winter baseflow (300 cfs) are anticipated in the near future. </p>
<p>The maximum winter release of ROD water under these Winter Flow
Variability actions would differ from year to year based on the water
year type, as follows:</p>
<ul><li>60,000 acre-feet in a Critically Dry water year,</li><li>80,000 acre-feet in a Dry water year,</li><li>120,000 acre-feet in a Normal water year,</li><li>180,000 acre-feet in a Wet water year, and</li><li>220,000 acre-feet in an Extremely Wet water year</li></ul>
<div id="ydp2a5373b9attachment_3608" style="width: 610px" class="ydp2a5373b9wp-caption ydp2a5373b9aligncenter"><a class="ydp2a5373b9trrp-lightbox ydp2a5373b9cboxElement" href="https://www.trrp.net/wordterrain/wp-content/uploads/2021/09/WinterFlowProposedAction2.png" title="Graph to demonstrate the proposed concept." rel="nofollow" target="_blank"><img class="ydp2a5373b9wp-image-3608" src="https://www.trrp.net/wordterrain/wp-content/uploads/2021/09/WinterFlowProposedAction2.png" alt="Graph to demonstrate the proposed concept." data-inlineimagemanipulating="true" style="width: 600px; max-width: 663px;" draggable="false"></a><p id="ydp2a5373b9caption-attachment-3608" class="ydp2a5373b9wp-caption-text"><b>Figure
1: Winter Flow Variability Actions Compared to Existing Conditions (No
Action), Using the 2016 Wet Water Year as an Example.</b><br>
The blue line represents the hydrograph that was implemented in 2016.
Green represents the timing of hypothetical water releases that could
occur with Winter Flow Variability. Grey line represents the full
natural flow. The full natural flow is the unimpeded contributions from
the blocked watershed area above Lewiston Dam. It shows the timing of
when water would have naturally been contributed to Trinity River if not
impounded by Trinity Lake.</p></div>
<h5 style="color: #167ac6;">Possible Impacts</h5>
<p>Possible impacts related to this management action that TRRP has been assessing include:</p>
<ul><li>Impacts on hydropower generation</li><li>Recreational impacts, including fishing, rafting, and boating</li><li>Biological impacts to the fishery, wildlife, vegetation, and wetlands</li></ul>
<h5 style="color: #167ac6;">Further Information</h5>
<ul><li><a href="https://www.trrp.net/restoration/adaptive-management/synthesis-reports/" rel="nofollow" target="_blank">TRRP Synthesis Reports Web Page</a></li><li>Reports that contrast current winter baseflows with more natural flows:
<ul><li>Buxton, T. H. 2021. <a href="https://www.trrp.net/library/document/?id=2483" rel="nofollow" target="_blank">History
of fine sediment and Its Impacts on physical processes and biological
populations in the restoration reach of the Trinity River, CA</a>. Report TRRP-2021-1 for the Trinity River Restoration Program (TRRP). TRRP, Weaverville, California.</li><li>Gaeuman, D. and R. Stewart. 2017. <a href="https://www.trrp.net/library/document?id=2357" rel="nofollow" target="_blank">Sediment transport in the Trinity River, CA: data synthesis 2004-2015</a>. Report TR-TRRP-2017-1 for the Trinity River Restoration Program (TRRP). TRRP, Weaverville, California.</li><li>Thomas Gast & Associates. 2021. <a href="https://www.trrp.net/library/document/?id=2492" rel="nofollow" target="_blank">Analysis and model evaluation of long-term data collected at the Willow Creek outmigrant trap.</a>
Report 20190910YTFP for the Trinity River Restoration Program (TRRP).
Thomas Gast & Associates Environmental Consultants, Arcata,
California.</li></ul>
</li><li>External Web Page: <a href="https://riverinstitute.humboldt.edu/trinity-river-benthic-macroinvertebrate-drift-project" rel="nofollow" target="_blank">Trinity River Benthic Macroinvertebrate Drift project</a></li></ul>
</div>
</div>
</div>
</div>
</div>
</div><div><br></div>
</div><div><br></div><div class="ydpbea88172signature">Tom Stokely <div>Salmon and Water Policy Consultant</div><div>530-524-0315 </div><div>tstokely@att.net </div><div><br></div></div></div>
<div><br></div><div><br></div>
</div><div id="yahoo_quoted_1649427680" class="yahoo_quoted">
<div style="font-family:'Helvetica Neue', Helvetica, Arial, sans-serif;font-size:13px;color:#26282a;">
<div>
On Tuesday, December 20, 2022 at 11:37:16 AM PST, Tom Stokely <tgstoked@gmail.com> wrote:
</div>
<div><br></div>
<div><br></div>
<div><div dir="ltr">This is about the Winter Flow Variability proposal even though it doesn’t mention it.<br></div><div dir="ltr"><br></div><div dir="ltr"><a href="https://mavensnotebook.com/2022/12/17/this-just-in-bureau-of-reclamation-plans-to-set-aside-a-twenty-two-year-old-agreement-on-trinity-river-hoopa-valley-tribe-asks-for-injunction/" target="_blank">https://mavensnotebook.com/2022/12/17/this-just-in-bureau-of-reclamation-plans-to-set-aside-a-twenty-two-year-old-agreement-on-trinity-river-hoopa-valley-tribe-asks-for-injunction/</a><br></div><div dir="ltr"><br></div><div dir="ltr"><br></div><div dir="ltr">Sent from my iPhone<br></div><div dir="ltr">_______________________________________________<br></div><div dir="ltr">env-trinity mailing list<br></div><div dir="ltr"><a ymailto="mailto:env-trinity@mailman.dcn.org" href="mailto:env-trinity@mailman.dcn.org">env-trinity@mailman.dcn.org</a><br></div><div dir="ltr"><a href="http://mailman.dcn.org/mailman/listinfo/env-trinity" target="_blank">http://mailman.dcn.org/mailman/listinfo/env-trinity</a><br></div></div>
</div>
</div></body></html>