Sediment Targets in the Boise River Tributaries Hawk Stone Idaho DEQ - - PowerPoint PPT Presentation

sediment targets in the boise river tributaries
SMART_READER_LITE
LIVE PREVIEW

Sediment Targets in the Boise River Tributaries Hawk Stone Idaho DEQ - - PowerPoint PPT Presentation

Sediment Targets in the Boise River Tributaries Hawk Stone Idaho DEQ Documents: Newcombe and Jensen (1996) Meat analysis: 80 studies How does sediment affect fish? 3 Questions Which grouping of fish Concentration of sediment


slide-1
SLIDE 1

Sediment Targets in the Boise River Tributaries

Hawk Stone Idaho DEQ

slide-2
SLIDE 2

Documents:

slide-3
SLIDE 3

Newcombe and Jensen (1996)

  • Meat‐analysis: 80 studies
  • How does sediment affect fish?
  • 3 Questions

– Which grouping of fish – Concentration of sediment – Duration of sediment

  • 1 Answer = Severity of Effect on fish
  • Use Matrix
slide-4
SLIDE 4

N&J EXAMPLE 1

slide-5
SLIDE 5

N&J EXAMPLE 2

duration is as important as concentration.

slide-6
SLIDE 6

Boise River TMDL CH2MHill Technical Memorandum

slide-7
SLIDE 7

Boise River Mainstem Target

50 mg/L for 60 days

slide-8
SLIDE 8

N&J Lower Boise River

slide-9
SLIDE 9

Tributary Sediment Targets

  • Keep as much as possible from the Lower

Boise River (mainstem) TMDL

– Same framework (use Newcombe and Jensen) – Same fishery (juvenile salmonids) – Same level of protection (SEV8)

  • BUT, sediment data show that we need a

different duration

slide-10
SLIDE 10

4 months 5 months

slide-11
SLIDE 11

4 months 5 ½ months storm event

slide-12
SLIDE 12

4 months 5 ½ months

slide-13
SLIDE 13

Proposed Target:

20 mg/L averaged over 4 months

Proposed Target 2:

403 mg/L for a maximum of 2 days