FLOOD06514

• County: Statewide
• Basin: Statewide
• Title: Colorado Erosion Control Manual
• Date: 11/1/1992
• Prepared For: CWCB
• Prepared By: USGS
• Floodplain - Doc Type: Floodplain Report/Masterplan

Plenning And PreUmlnlll'Y Design

e

FIGURE 5- 1

Planning and preliminary design procedure

I
Conduct Site Reconnaissance
I

Planning & Preliminary Design
I

I
Collect Needed Data
I

I
Identify Cause of Erosion

I
Select Technically Feasible Alternatives
& Estimate layout, Design, Quantities, etc.
I

Conduct Economi~ Analysis
I

I
Identify Project Constraints
I

I
Subject Each Alternative To
Constraints & Economic Evaluation

I

Select Most Appropriate Solution

Review For Attainment Of Objectives

5.2.1 Need.

Underslallding river behavior in general, or the behavior of a particular river, requires
observatiun of the flow in various reaches at various discharges from low flow to flood
flow. MaJ: s, aerial photogrnphs, measurements, and pictures from the past can all help in
understan:ling what has happened and, therefore, can happen again; but they cannot
entirely sobstiblte for seeing and experiencing the river. Only by first establishing a
qualitativ'l sense for river behavior can one interpret meaningfully the numbers or
predictior s that can result from the application of the ''theories" of river flow and
sediment transport. This is because the "theories" include many assumptions (both
explicit Hnd implicit), relationships obtained by curve fitting with little or no
rationaliz;ttion, and coefficients or factors which must be evaluated using "judgment" or
based upcn "experience."

Ch8ckII!ll .

The nature and extent of the information which should be collected during a site
reconnaislance is quite extensive. For that reason, it is recommended that a checklist be
used to eusure an adequate review. Table 5-1 presents a typical checklist for an initial
reconnais lance.

e

54

Colorad,o Erosion Control Manual