Lakes of Missouri Volunteer Program University of Missouri-Columbia The Missouri’s Lakes and Reservoirs 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 Tony Thorpe Dan Obrecht Jack Jones

405 Classified Lakes/Reservoirs ~108 are Drinking Water Supply (LC1) 14 are Major Reservoirs (LC2) Most are man-made reservoirs, with about oxbow lakes.

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

Lake Morphology Surface Area Depth Volume Lake Hydrology Watershed Area Residence Time External Loading Land Use

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

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

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

Lake Volume Ranges from 48 to 2,700,000 acre-feet, with a median of 1,675 acre-feet. 1 acre-foot = 325,851 gallons 1 acre 1 foot

Lake Hydrology

Watershed Area Ranges from 83 to > 4,000,000 acres, with a median of 2,516 acres.

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

External Loading

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 >= 4 years worth of data

Land Cover and Water Quality: Row Crop Data points based on summertime averages near the dam

Land Cover and Water Quality: Forest Data points based on summertime averages near the dam

Trophic Classification Oligo Meso Eutro Hyper TP TN CHLa

Distributions based on long-term averages

Phosphorus (micrograms per liter) # of waterbodies IX – 20 ug/L XI – 8 ug/L (EPA recommendations as of July 2002)

Nitrogen (micrograms per liter) # of waterbodies IX – 360 ug/L XI – 460 ug/L (EPA recommendations as of July 2002)

Chlorophyll (micrograms per liter) # of waterbodies IX – 4.9 ug/L XI – 2.8 ug/L (EPA recommendations as of July 2002)

Break down by size “Small” Reservoirs: less than 2000 acres “Large” Reservoirs: more than 2000 acres

“Large” Reservoirs 2004 LMVP Data

“Small” Reservoirs Inset is to scale 2004 LMVP Data

Types of Variability Temporal Spatial

Temporal Variability

Little Dixie Lake – Seasonal Patterns 2004 LMVP Data Phosphorus (ug/L)

Little Dixie Lake – Seasonal Patterns Phosphorus (ug/L)

Range = 37 – 95 ug/L

Spatial Variability

Phosphorus Concentrations: Lake of the Ozarks Variability within a lake 2002 LMVP Data

Phosphorus Concentrations: Table Rock Lake Variability within a lake 2002 LMVP Data

930 acres Approximately 1 mile between the two sites Phosphorus Concentrations: Longview Lake Variability within a lake