Lakes of Missouri Volunteer Program Lake Morphology and Hydrology The Lakes of Missouri Volunteer Program University of Missouri-Columbia 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

Lake Morphology/Hydrology Surface Area Depth Volume Watershed Area Flushing Rate

Ranges from 6 to 53,814 acres in size, with a median of 103 acres. Surface Area Depth Volume Watershed Area Flushing Rate Surface Area Ranges from 6 to 53,814 acres in size, with a median of 103 acres.

Surface Area of Classified Lakes Depth Volume Watershed Area Flushing Rate Surface Area of Classified Lakes 30% of classified lakes are 20 acres or less in size. 10% are greater than 300 acres in size.

Depth (determined by dam height) Surface Area Depth Volume Watershed Area Flushing Rate Depth (determined by dam height)

Ranges from 3.7 feet to 62 feet, with a median of 11.6 feet. Surface Area Depth Volume Watershed Area Flushing Rate Average Depth Ranges from 3.7 feet to 62 feet, with a median of 11.6 feet.

Why is depth important? Shallow lakes may mix sporadically throughout the summer, leading to more internal loading of nutrients. A deeper lake has a larger volume of water, which influences hydrology.

Lake Volume (determined by area and depth) Surface Area Depth Volume Watershed Area Flushing Rate Lake Volume (determined by area and depth)

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

Same inflow volume, different Lake Volume Surface Area Depth Volume Watershed Area Flushing Rate Same inflow volume, different Lake Volume Dam height and topography determine the lake volume

Watershed Area (catchment size) Surface Area Depth Volume Watershed Area Flushing Rate Watershed Area (catchment size)

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

Same size lake, but with different inflow volumes Surface Area Depth Volume Watershed Area Flushing Rate Same size lake, but with different inflow volumes Inflow is determined by the watershed area and rainfall

Surface Area Depth Volume Watershed Area Flushing Rate Flushing Rate - the proportion of the total lake volume that is replaced (per year) by inflowing water. Flushing Rate = Regional Runoff Coefficient * Watershed Area / Lake Volume

Ranges from 140 to 0.1, with a median of 1.1 Surface Area Depth Volume Watershed Area Flushing Rate Flushing Rate Ranges from 140 to 0.1, with a median of 1.1

Flushing Rate = 0.5 Flushing Rate = 1 Flushing Rate = 2 Annual Inflow / Volume = Flushing Rate inflow 50 outflow 50 Volume 100 Flushing Rate = 0.5 Volume 100 outflow 100 inflow 100 Flushing Rate = 1 outflow 200 inflow 200 Volume 100 Flushing Rate = 2

Why is Flushing Rate important? Flushing Rate is used to gauge inputs relative to lake volume. A 100 acre lake with a low flushing rate has fewer inputs than a 100 acre lake with a high flushing rate.

Same lake volume, different Inflow Volume Surface Area Depth Volume Watershed Area Flushing Rate Same lake volume, different Inflow Volume High Flushing Rate Low Flushing Rate

Same inflow volume, different Lake Volume Surface Area Depth Volume Watershed Area Flushing Rate Same inflow volume, different Lake Volume High Flushing Rate Low Flushing Rate

Quick Ecoregion Overview

Missouri’s Physiographic Regions Glacial and Osage Plains Ozark Border Ozark Highlands

Average Phosphorus Values (for physiographic regions) Region Phosphorus (ug/L) Glacial Plains 44 Osage Plains 73 Ozark Border 40 Ozark Highlands 17