Table 4-26 TOC
Water Quality Index (WQI) Ratings, by Hydrologic Basin, for Samples Selected during 1982-1987
  Avg WQI Rating
 
Station Name Overall Worst 3 Mo. Date of Last Sample
  Bear River Basin
 
Bear River at Wyoming stateline 51 67 9/30/87
     at Soda Springs 28 46 9/6/83
     near Preston 24 40 9/6/83
 
  Upper Snake Basin
 
Snake River near Heise 15 21 9/30/87
Henry's Fork near Rexburg 18 30 9/7/83
Snake River at Menan 10 13 9/7/87
     below Blackfoot 27 52 9/7/83
     near Blackfoot 40 59 9/7/83
Portneuf River at Siphon Road 60 72 9/7/83
Snake River at Burley 15 23 9/19/93
Rock Creek at mouth near Twin Falls 46 79 9/28/87
Salmon Falls Creek above mouth 26 44 12/13/84
Malad River above Malad Canyon 23 38 9/19/83
Snake River at King Hill 20 23 9/30/87
 
  Southwest Basin
 
Bruneau River near Bruneau 36 76 9/29/83
Boise River below Lucky Peak Dam 6 7 9/30/87
     at Glenwood Bridge 20 25 9/30/87
     near Middleton 30 37 9/30/87
     near Parma 65 81 9/30/87
Snake River at Marsing 28 40 9/26/83
Payette River at Hartsell Bridge 12 29 9/30/87
     below Black Canyon Dam 14 20 9/30/87
     at Letha Bridge 28 41 9/30/87
     near Payette 35 66 9/30/87
Snake River at Weiser 49 69 9/30/86
Weiser River near Weiser 43 61 9/28/84
Snake River at Hells Canyon Dam 26 29 9/30/86
 
  Clearwater River Basin
 
Clearwater River at Spaulding 19 29 9/30/87
     at Orofino 8 17 9/21/83
North Fork Clearwater at Ahsahka 4 5 9/21/83
Coeur d'Alene River at Enaville 11 17 9/14/83
South Fork Coeur d'Alene River at Enaville 62 70 9/14/83
Coeur d'Alene River at Rose Lake 53 57 9/14/83
St. Joe River at St. Maries 8 11 9/14/83
Spokane River at Post Falls 29 36 9/30/87
Clark Fork River at Cabinet Gorge 2 26 9/22/87
Pend Oreille River at Newport 8 14 9/30/87
Kootenai River at Porthill 14 21 9/30/86
     near Copeland 16 26 9/30/83
 
  Salmon River Basin
 
Salmon River at Whitebird 16 34 9/30/87
Source: Idaho Division of Environmental Quality, Water Quality Bureau, Idaho Water Quality Status Report and Nonpoint Source Assessment, 1988.
Notes: WQI Rating Definition
  0-20 Good Water quality is generally high, and beneficial uses are fully supported.
  21-60 Fair Water quality is periodically marginal, and uses are partially supported.
  61-100 Poor Water quality is poor, not supporting beneficial uses.

Originally compiled by: Diane Prorak
Data input assisted by: Robert Anton-Erik
Conatct: Lily Wai