WSP01701

• File Number: 8220.114.I
• Description: Dolores Participating Project
• State: CO
• Basin: San Juan/Dolores
• Water Division: 7
• Date: 6/9/1980
• Author: USDOI-USFWS
• Title: Biological Opinion - Dolores Project
• Water Supply Pro - Doc Type: Biological Opinion

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6

Eo.ld e;!'..r:l~

A pair of bold eagles at Totten Reservoir is regularly being observed this
spring by the Colorado Division of Wildlife (DO~). Due to the behavior the
eagles are cisplaying it is assumed they have produced eggs and are now
L,cubatiug.Although Totten Reservuir is ~~thin the project area bOlli~dary,
it is our opinion that construction and operation of the ,DOlores Project
~~l not adversely itpact this pair of eagles because of their distance
fro::J ~be projec.t site.

l~st bald eagles in Colorado are ~~nter residents. Winter residents arriva
L, Septenber and the popu1~tion increases slowly from October through
Dece~~er. The period of highe~t use is Dec~ber through l~rch. Seven
h=dred bald C2.gles wintered in, Colorado this year. The northern Idgration
begins in late February and IllOst e2sles have left Colorado by ea::ly April.
TIle Bure2u of Lend Hanag(>~~nt =d Color2.do Division of I-!ilclife have
identified bald eagles in the area to be inundated by HcPhee Reservoir, and
in the Dolores River canyon below the HcI'hee Dam site,

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n~e ~ThS'S Fi~" Environmental State~nt for the Dolores Project states
that 16.5 miles of the'Dolores River and 443 acres of 'riparian habit2t
~ou1d be in~dated by the proposed project. Tbe biological assessoent
states "that the Dolores Project ;'ill 1'.-obably enhance the distribution
&:od abU:lG.ance or bald eagles in the Dolores :River Basin." However. "'e fail
to 8ee how this Yill occur. Habitat suit~ble fo~ ~~nteri~g bald eagles
should contain large open perch trees neer adequate foed supplies. As
€Y~5ting reservoirs are frozen over during the ~~nter1 ~e eJ~ect all project
re.se.r,,'"oirs t:.o also be ice covered, thereby l-r,..,iting their food value.
Further20re, drawing down r~nee and P~nuwent Creek Reservoirs by 3S~ and
70~ respectively, ~2Y prevent the establishment of cottonwood trees along
t;,e shordine. It is also uncertain vhat long-tem iI:l?ect to riparian
vcgetstio~ vill occur as a result of depleting spring flows below ~kPhee
D=. A loss of cotton,,-ood regeneratiDn could in!pact perc.'o site availability.
~e believe the developments proposed for ~dlife ,nIl oitigate the loss of
bald e<'-"le hunting habitat, but not improve =nditions for ~"intering eagles
beyond \...hu~ ,""auld erist w~thout project develop:nent.

Ho~cver, ~~ntering conditions for bald eagles could be opt~zed by impl~cnting
~~~~gc~ent guidelines identified by Steenhof (1978). This may include
selecti7e clearing of trees, tr~ing young tree stands, or establishing
n~~ tree stenose ~e reco~nd that an interabe~cy te~ be convened to
dcter-~"1e which ~2..aag~nt tecr.r..iques W'ocld be app:-opriate for the Dolores
Proj ect. MG.itional f=c.ing required should be provided by ~1'RS.

The: assossment does not edd~ess the 1!-::act.s to bald eagles that nay result
...~;:h develop=nt of recre~tion sites belot,' HcPhee j)a::l and adjacent to
HcYnea Reservoir. lore do not antic.ipnte negative i=::pacts to eagles as a
rC5ul~ of ~y of the recreation sites. ~evelop~nt belo~ the dae incorporat~s
rete~tion of =cst =stu~e cot~o~~oCa to pro~~de adeq~te shede for public
use. T~is t,~11 also prevent siSUifican;: loss of day perch sites.