FLOOD10358 ‎(2)‎

• Document ID: 124
• County: Alamosa
• County: Rio Grande
• Community: Rio Grande and Alamosa CountiesRio Grande and Alam
• Stream Name: Rio Grande RiverRio Grande River
• Basin: Rio Grande
• Sub-Basin: Upper Rio Grande
• Water Division: 3
• Title: Rio Grande Headwaters Restoration Project
• Date: 10/1/2001
• Prepared For: San Luis Valley Water Conservancy District, RGHRP Technical Advisory CommitteeSa
• Prepared By: Montgomery Watson Harza
• Watershed Pro - Doc Type: Project Report

.

The T AC rated each of the criteria equally for sub-reach E3. The low riparian habitat and
diversion access scores are the primary reasons for the low overall score for the sub-reach.
In sensitivity analysis of weighting schemes, this sub-reach is the most sensitive, and could
be replaced in the top ten by sub-reach BB2 or D7.

.

.

TAC Relative Importance of Sub-Reach Evaluation Criteria
Criteria Importanc~
Riparian Diversion
Habllat Access

Table ES-S.

.

not only a function of lower floodplain and
criteria by the T AC, but are also a function of

Low scores in sub-reaches E5 and F2 are
capacity scores, as rated the most important
poor riparian habitat and poor diversion access.

.

Comments
recreation~
recreational value
recreational value
recreational value
recreational value

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Channel
Slablllly

2

Floo'.!plaln
1

Channel
Capaclly

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2

The sub-reaches with the lowest weighted scores have Ihe highest restoration priority for achieving the project
objectives, given the weights developed by the T AC. However, other projects outside these poorly rated sub-
reaches may also be proposed.

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1

Weighted
S!:2.,re
5.2
7.2
6.5
7.6
6.1
3.4
6.0
7.5
7.4
6.0
6.3
6.5
7.2
5.6
4.5
6.9
2.4
5.0
IT
6.0
6.6
7.4
5.6
7.7
5.0
6.1
5.0
6.2
7.2
7.3

Channel
Stabllltv
iQ.O
9.4
6.8
6.8
5.7
9.9
10.0
10.0
6.3
~
6.0
9.0
5.8
5.8
2.1
4.5
0.0
9.5
1.2
7.7
6.4
9.1
6.3
7.9
6.8
6.5
7.3
8.0
6.4
8.1

Enhancement and Monitoring Plan

Channel
Capacity
4.9
--:r.o-
-rr-
~
5.1
~
10.0
10.0
6.7
9.5
9.8
~
~
~
2.9
~
4.6
~
-----s:s-
-rr-
-----s:s-
~
---s:g-
---e:a-
5.0
~
~
~
4.7
4.5
IndiCiii;;Siii8lowest

~ach
A1
-----;\2
~
~
~
-----;\6
-sAT
-sA2
-sB1
-sB2
--cr
---c2
---c3
------01
-----02
--00
--04
-os
---os
-o?
~
~
~
~
--rr
F1
F2
--err
-----02
~
NOte:

Existino development is f1oodprone
Consolidate headgates
Development pressure. Restore
floodplains.
Development pressure. Restore
flOodplains.
Development pressure. Restore
floodplains.
Restore function floodplains.
Restore function floodplains.
Restore function floodplains.
Restore function floodplains.
Restore function floodplains.
Restore function floodplains.
Restore function floodplains.
Development pressure. Restore
floodplains.

2

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2
'1
I
1
1

g
1
2

2
g:
2
'1
'1
'1
'1

1
I
1
1
2

Sub.:!!!,ach
A1
A2
A3
M
AS
AS
BA1
BA2
BB1
BB2
C1
C2
C3
01

04
55
56
E1
E2
@
E4
E5

02

03

2
2

F1
F2
G1
G2
G3

Fix Westside Diversion.

New Ditch.

2
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2

important criterion.

Based on the technical scores and the T AC weighting for each of the sub-reaches, an overall score for each
sub-reach was developed. The nonnalized technical scores for each criteria and the composite scores are
shown in Table ES-6. The 10 sub-reaches with the overall lowest weighted scores are highlighled. The
following is a summary of Ihose reaches.

indicating the most

Numbers represent relative importance of criteria, with

Notes:
(

ES.4

Low scores in sub-reaches A I, A6, and D2 are driven primamy by the low scores for
channel capacity and/or floodplains, and the relative importance placed on the criteria by
the TAC. These areas encompass portions of South Fork, Del Norte and the oulskirts of
Monte Vista, respectively.

Sub-reach D 1 is primarily influenced by poor scores in diversion access, which was ranked
as important by the T AC. The sub-reach contains the Pace, Consolidated Slough and Butler
Ditch diversions.

.

Solutions have been proposed for each of the river sub-reaches for which unsatisfactory river conditions were
idenlified, and for specific locations outside these sub-reaches where significant localized problems were
identified. Alternatives have been developed based on accepted stream stabilization and riparian corridor
management methods. Proposed projects include structural measures and non-struclural measures. Projects
have been priori Ii zed based on their ability to address problems in Ihe worst-ranked sub-reaches.

8

ES-

River conditions for sub-reaches D4, D5, 06 and D7 are symptomatic of the dynamic state
of the river system in the area, which results in low scores for channel capacity, channel
stability, diversions and riparian habitat Increased channel stability in the area would likely
result in higher scores for Ihe other decision criteria.

.

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ES-17