Basic Standards Workgroup 12/16/2015 WQCD - Temperature Issues
Water Temperature and Elevation At higher elevation Lower max temp Longer time below temperature thresholds Elevation central to transition zone problem Elevation central to shoulder season problem 25 20 MWAT, o C 15 10 5 0 Dec-11 Apr-12 Jul-12 Oct-12 Jan-13 May-13 Aug-13 Nov-13 Mar-14 State Line (4325) Glenwood (5760) abv Shadow Mt (8386)
Shoulder Seasons • Elevational constraint on the Pattern • Physiological Requirements of the fish • Regulatory Framework – Recognize natural gradient – Flexibility in the face of uncertainty
Winter Start Date 5-Dec Median Start Date MWAT<9 15-Nov 26-Oct 6-Oct 16-Sep y = -0.0099x + 355.6 27-Aug R² = 0.8497 7-Aug 18-Jul 3000 5000 7000 9000 11000 Elevation, ft
Winter Duration 400 Median Duration MWAT<9 350 y = 0.0326x - 11.535 300 R² = 0.8733 250 200 150 100 50 0 3000 5000 7000 9000 11000 Elevation, ft
WAT-Trapper Creek 18 16 14 Highest WAT °C 12 10 8 6 4 2 0 1-Jan 20-Feb 10-Apr 30-May 19-Jul 7-Sep 27-Oct 16-Dec Ordinal Day 2008 2009 2010 2011 2012 2013 CS-I MWAT steps
Shoulder Season Questions • What are the pros and cons of narrative option? • Are there options to include an elevational component? • Could alternative averaging periods be used?
Bear Creek at O'Fallon Park Sept -Oct 2008 WAT ( ° C) 18 16 14 12 10 WAT MWAT 8 Av 6 4 2 0 8/30 9/14 9/29 10/14 10/29
Transition Zones • Elevational Constraints • Nexus with Physiological Requirement • How can we recognize the natural gradient in the regulatory framework
Max MWAT All Sites Fitted Line Plot Max_WAT_Pt = 35.92 - 0.002409 Elevation_Pt 35 Regression 95% CI 95% PI 30 S 2.08009 R-Sq 77.8% R-Sq(adj) 77.7% 25 Max_WAT_Pt 20 15 10 3000 4000 5000 6000 7000 8000 9000 10000 11000 Elevation_Pt
Regulatory Framework / Policy Issues • Implementation options? – Apply broadly, statewide – Limit application (by stream order, other?) – Add equation to Reg #31, but apply it on a segment-by-segment basis • Other Policy questions
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