1400 ‎(2)‎

• UCREFRP Catalog Number: 1400
• Author: Simons, D. B., et al., ed.
• Title: Proceedings
• USFW Year: 1980.
• USFW - Doc Type: Workshop on Downstream River Channel Changes Resulting From Diversions or Reservoir Construction.
• Copyright Material: NO

In order to evaluate the above-mentioned effects, an analysis of
hydrological, hydraulic, morphological, and thermal changes is required.
Hydrologic analysis will establish the flow occurrence frequencies for
all of the main rivers and major tributaries. Hydraulic analysis will
estimate the hydraulic parameters such as velocity. depth, top width,
and wetted perimeter that are requi red to conduct the sediment and
morphological studies and evaluate changes induced in the fish spawning
capacity of the system. Sedimentation analysis will analyze the impact
of siltation on the hydraulic parameters that govern fish habitat due to
construction of the project. Careful scheduling of construction activi-
ties may be required to minimize impacts. The morphological studies
will consider the changes that can be expected to occur over time in the
river profile and cross section along a study reach. A thermal study
should consider the thermal regime in the river resulting from selected
withdrawal of water from a multilevel intake structure.

PROPOSED SCOPE OF WORK

The fo 11 owi ng genera 1 scope of work is suggested by the
participants' papers in order to adequately analyze the responses of a
reach below a dam or reservoir.

1. Conduct site visits to become familiar with the physical
environment. All participants agreed that this is absolutely
essential to any adeq/uate analysis of the system.

2.

Collect, collate, synthesize, and verify available hydrologic,
hydraulic, thermal, topographic, sediment, cross-sectional,
geological, structural, and fish habitat data pertinent to the
study (see the data base section which follows).

3. Evaluate the data available for analysis, identify the
immediate data gaps, and recommend an effective short term
in-field data collection program.

4. Conduct in-field data collection of cross-sectional data,
ve 1 ocity, depth, wi dth, and bed ma teri a 1 and suspended sedi-
ment samples in the river system of concern. Participants
agreed unanimously that the data packages provided were not
adequate for more than a preliminary qualitative assessment
and must be supplemented to support quantititive analysis.

5. Compile and develop a spatial representation system that
approximates the study area. This spatial design will provide
a 1 i ne di agram showi ng the watersheds, reservo; r, ri ver mi 1 e,
cross-sectional numbers, location of structures, fish habitat
reaches, bed material sampling points, geologic controls, and
works of man such as construction roads.

6.

Review and evaluate the hydrologic changes in the river system
induced by the dam.

8

.

.

.