Lakes%20of%20Missouri%20%20Volunteer%20Program

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Lakes of Missouri Volunteer Program
Missouris Lakes and Reservoirs
Tony Thorpe Dan Obrecht Jack Jones
The
The Missouri Department of Natural Resources
Region V11, US Environmental Protection Agency,
through the Missouri Department of Natural
Resources, has provided partial funding for this
project under Section 319 of the Clean Water Act
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405 Classified Lakes/Reservoirs

• 108 are Drinking Water Supply (LC1)
• 14 are Major Reservoirs (LC2)
• Most are man-made reservoirs, with about 15 - 20
  oxbow lakes.

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Of the 405 Classified Waterbodies, we have at
least 4 years worth of data on 134
What follows is a summary of the physical
features of those 134 waterbodies
A central paradigm of modern limnology is that
external nutrient loading, modified by morphology
and hydrology, determines the trophic state of a
lake. Jones et al. 2005
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Lake Morphology

• Surface Area
• Depth
• Volume

Lake Hydrology

• Watershed Area
• Residence Time

External Loading

• Land Use

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Surface Area

• Ranges from 6 to 53,814 acres in size, with a
  median of 103 acres.

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Break down by size
30 of classified lakes are 20 acres or less in
size. 10 are greater than 300 acres in size.
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Average Depth

• Ranges from 3.7 feet to 62 feet, with a median of
  11.6 feet.

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Lake Volume

• Ranges from 48 to 2,700,000 acre-feet, with a
  median of 1,675 acre-feet.

1 acre
1 foot
1 acre-foot 325,851 gallons
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Lake Hydrology
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Watershed Area

• Ranges from 83 to gt 4,000,000 acres, with a
  median of 2,516 acres.

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Residence Time

• Ranges from 2.6 days to 9 years, with a median of
  10.5 months.

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External Loading
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Land Cover within watersheds

• Forest 0 95
• Grass 0 78
• Crop 0 74
• Urban 0 96

Using the 134 classified lakes for which we have
gt 4 years worth of data
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Land Cover and Water QualityRow Crop
Data points based on summertime averages near the
dam
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Land Cover and Water QualityForest
Data points based on summertime averages near the
dam
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Trophic Classification

• Oligo Meso Eutro Hyper
• TP 10 36 81 7
• TN 11 22 92 9
• CHL a 15 23 92 4

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Distributions based on long-term averages
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Phosphorus (micrograms per liter)
IX 20 ug/L XI 8 ug/L
(EPA recommendations as of July 2002)
of waterbodies
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Nitrogen (micrograms per liter)
IX 360 ug/L XI 460 ug/L
(EPA recommendations as of July 2002)
of waterbodies
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Chlorophyll (micrograms per liter)
IX 4.9 ug/L XI 2.8 ug/L
(EPA recommendations as of July 2002)
of waterbodies
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Break down by size
Large Reservoirs more than 2000 acres
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Large Reservoirs
2004 LMVP Data
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Small Reservoirs
Inset is to scale
2004 LMVP Data
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Types of Variability

• Temporal
• Spatial

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• Temporal Variability

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Little Dixie Lake Seasonal Patterns
Phosphorus (ug/L)
2004 LMVP Data
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Little Dixie Lake Seasonal Patterns
Phosphorus (ug/L)
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Range 37 95 ug/L
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• Spatial Variability

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Phosphorus Concentrations Lake of the Ozarks
Variability within a lake
2002 LMVP Data
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Phosphorus Concentrations Table Rock Lake
Variability within a lake
2002 LMVP Data
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Phosphorus Concentrations Longview Lake
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930 acres Approximately 1 mile between the two
sites.
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Variability within a lake
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