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In-channel Mining

In-channel mining can directly effect stability by lowering local base flow level, causing headcuts, channel incision, changing dimension, pattern and profile, and accelerating streambank erosion. The nature, extent and consequence of channel adjustments is influenced by stream type, thus risk ratings are adjusted accordingly. The data needed for this assessment are

a) Stream types
b) Length of stream affected
c) Nature and extent of mining

The assessment of risk for in-channel mining is based on the direct disturbance in relation to the percent of channel length impacted and is shown in Figure 83.

Figure 83

Risk ratings for various river reaches are summarized in Worksheets 5a & 5b and for multiple locations in Worksheet 6. The risk rating summary will be used for evaluation of channel enlargement and degradation potential.

Worksheet 5a: Printable PDF (10 kb, 1 p.) | Excel Spreadsheet (27 kb)
Worksheet 5b: Printable PDF (9 kb, 1 p.) | Excel Spreadsheet (35 kb)
Worksheet 6: Printable PDF (8 kb, 1 p.) | Excel Spreadsheet (21 kb)

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