• If you are citizen of an European Union member nation, you may not use this service unless you are at least 16 years old.

  • You already know Dokkio is an AI-powered assistant to organize & manage your digital files & messages. Very soon, Dokkio will support Outlook as well as One Drive. Check it out today!


Flathead Lake Nutrient Standards

Page history last edited by Christina Staten 7 years, 12 months ago Saved with comment

Links to the Flathead TMDL Project Pages


Flathead Lake Nutrient Standards Development


Page Contents: 


Meetings & Presentations


Presentations & Meeting Summary

April 13, 2015

1:30 p.m., FWP Conference Room, Kalispell


DEQ held a kick-off meeting to discuss the development of nutrient standards for Flathead Lake.


Draft April 13, 2015 Presentation by Michael Suplee (5.44 MB)


Technical data and materials for this meeting can be found in the “Documents” table below. You may either download a zip file containing all of the files , or download each file individually.


Meeting Summary

May 24, 2016

1:30 p.m., CSKT Natural Resources Department, Polson


DEQ held a meeting to continue discussions of appropriate nutrient criteria to adopt for Flathead Lake.


Meeting Agenda


Marc Lorenzen Presentation (1.16 MB) 

Marc Lorenzen gave a presentation regarding the relationships between chlorophyll a, suspended solids, secchi depth, and lake clarity. 


Shawn Devlin Presentation (2.49 MB)

Shawn Devlin, a researcher with the Flathead Lake Biological Station, gave a presentation regarding the status of their Flathead Lake model: it's inputs, outputs, and timeline for completion. 


A meeting summary will be available soon.



Meeting Materials & Documents


File Description

Date Posted

Materials for April 13, 2015 Meeting
4/7/15 Zip File (1.44 MB) Zip file of all files posted below on 4/7/15 for the April 13, 2015 kick-off meeting. 4/7/15

FlatheadLake_AvgAnnual_ALL.xlsx (<0.1 MB)

Compilation of key average annual data points for Flathead Lake (from Midlake Deep) which DEQ located or calculated


FlatheadSecchi_WY1978-87.xlsx (~0.1 MB)

FlatheadSecchi_EPAdata_WY1991-2011.xlsx (~0.3 MB)

Flathead_WY1975_EPAdata.xlsx (< 0.1 MB)

DEQ’s annual average calculations derived from older secchi depth data


Secchi78-87.tif (~0.2 MB)

Picture file showing graph from which secchi depth data were extracted


FlatheadChla_WY85-96.xlsx (< 0.1 MB)

Annual average calculations derived from older Midlake Deep phytoplankton chlorophyll a data


Chlorophylla85-96.tif (~0.5 MB)

Picture file showing the graph from which the chlorophyll a data were extracted


MidLakeDeep_ExceedenceCalc.xlsx (<0.1 MB)

A MS Excel spreadsheet that can be used to calculate the allowable exceedance rate for several different potential lake standards


Models_Chla_TP_Secchi_Carlson.xlsx (< 0.1 MB)

A MS Excel file containing various empirical models which can be used to predict lake chlorophyll a, secchi depth, etc.


Materials for May 2016 Meeting
SSChlSecchiGraph_Lorenzen.xlsx (< 0.1 MB) Graph of relationship of chlorophyll a and suspended solids to secchi depth, provided by Marc Lorenzen 11/10/15



DEQ Contacts

DEQ Contact




Michael Suplee

Flathead Lake Nutrient Water Quality Standards Development


(406) 444-0831

Christina Staten

TMDL Project Coordinator


(406) 444-2836

Myla Kelly

Water Quality Standards Section Supervisor


(406) 457-3639




Page Created: April 7, 2015

Last Edited: May 27, 2016


Information on the Flathead Lake Watershed nutrient, sediment, and temperature TMDLs can be found on the Flathead TMDL Project Welcome Page