Lake Olathe Watershed of Olathe, KS
Liz Coffey
Spring 2010
Hydrologic Setting
Water Resources
Conclusions
Hydrologic & Geologic Properties
Groundwater Quality & Contaminatio
References
Hydrologic Setting
The Lake Olathe watershed extends over 43 km2 (10,800 acres) of land that encompasses the
drainage areas of Lake Olathe, Cedar Lake, and Cedar Creek. (Fig.2) Cedar Creek is the main
tributary that links the two lakes together. Surface area of Lake Olathe covers 0.68 km2 (170 acres)
and Cedar Lake covers about 0.21 km2 (54 acres). The surface waters are used for recreation
purposes and a drinking water source for many residents. Land use of the area is about eighty-three
percent used as agricultural cropland and grassland. (Mau, 2004) The Lake Olathe watershed is
overlying the Western Interior Plains Aquifer System that extends through Kansas, Missouri, and
Nebraska as seen in Figure 1.
Figure 1. Extent of the Western Interior Plains aquifer system shown in purple. (USGS, 1997)
The range of precipitation averages for the area is 3.0 cm (1.2 in) to 13.3 cm (5.24 in) for a
maximum in the month of June. (HPRCC, 2009) The average precipitation of the area is 101.6 cm (40
in) that occurs primarily during the growing season between April and October. Average temperature
for the year is 22.2 C (55 F) with an average temperature of January as -3.8 C (29 F) and July as
46.2 C (79 F). (Mau, 2004)
Figure 2. Location of Lake Olathe watershed, land use in the watershed, and real-time water
quality monitors. (USGS, 2004)
Return to top
Hydrologic & Geologic Properties
The Lake Olathe watershed is underlain by sedimentary bedrock deposited during late
Pennsylvanian time (about 285 to 320 million years ago). The bedrock is mostly shale, with some
prominent limestone layers and sandstone. Pre-Illinoian glacial till and a thin layer of loess (windblown Pleistocene deposits) cover the bedrock. Soils in the watershed were formed from windblown
loess, glacial outwash, and residuals derived from the weathering of shale and limestone bedrock
(Mau, 2004).
Recharge to the aquifer involved is seasonal due to the variability of the precipitation to the area.
Ground water moves downward through permeable rocks due to gravity and moves east from the
southeast laterally. The yield is generally less than 50 gpm for the wells in Olathe, KS. (O’Conner,
1971) The structure and character of the rocks may affect the direction and rate of movement of the
water. Ground water may discharge into the three water bodies of the watershed or may evaporate or
transpire by plants. Some of the groundwater is discharged from wells by those not close enough the
water lines from the two lakes but is very minimal. Over a long period of time, equilibrium generally
exists between the recharge and discharge. (O’Conner, 1971) Ground water of the Western Interior
Plains Aquifer System has an average of concentrations of 1,000 mg/L of total dissolved solids with a
maximum of 200,000 mg/L concentration. Water from this aquifer system is not generally pumped
due to its highly mineralized nature and its deep burial of about 76 m.(250 ft.). Although it is deeply
buried, the aquifer thickness ranges from 457 m. (1,500 ft.) to 305 m.(1,000 ft.) (USGS, 1997)
Figure 3. Map shows aquifer thickness of the extent of the Western Interior Plains aquifer system in
feet. The circle shows the general location of Johnson County, KS. (USGS, 1997)
Physical Characteristics of Cedar Lake and Lake Olathe.
[--, not applicable]
Characteristic (unit of measurement)
Total storage volume at dam crest elevation (cubic meter),
2000
Surface area (square kilometers)
Mean depth (meters)
Maximum depth (meters)
Mean annual inflow (cubic meters per second)
Drainage area of watershed (square kilometers)
Cedar Lake
Lake Olathe
4.1E5 (334 acre-foot)
3.8E6 (3,100 acre-foot)
0.22 (54 acres)
1.9 (6.20 ft.)
4.3 (14.0 ft.)
-15.8 (6.10 sq.mi.)
0.69 (170 acres)
5.5 (18.2 ft.)
13.4 (44.0 ft.)
0.44 (15.6 c.f.s)
28 (10.8 sq.mi.)
(Table taken from Mau, 2004)
Return to top
Water Resources
Water from the Lake Olathe watershed is used extensively for drinking water and recreation.
There are approximately 1,500 residents in the watershed that live mostly in single-family homes and
farms with the city of Olathe nearby with a population well over 100,000 residents. The watershed
area is experiencing rapid development and urbanization. Guidelines have been set for development
in the Lake Olathe watershed by the City of Olathe. These guidelines are based on Best Management
Practices propagated by the Mid America Regional Council and the American Public Works
Association. (City of Olathe, 2010)
After some concern was raised with Lake Olathe and Cedar Lake’s bottom sediments and their
chemical properties, samples were taken from both locations. To precede the sampling bottom
sediment mapping was conducted in July 2000 for Cedar Lake and Lake Olathe. The sampling
provided information that was used to help describe the effects of industrial, agricultural, residential
activities in the watershed. After analysis, it was found that there were large mean concentrations of
phosphorous and a few trace elements were present in the lake bottoms. A study done in 2005
concluded that there were also elevated concentrations of manganese in both lakes but an emphasis
was made on Lake Olathe because its use as drinking water. High concentrations of phosphorous
could lead to eutrophication (nutrient enrichment) that degrades water quality. An eutrophication
condition in the lakes would provide a food source for phytoplankton (algae) that may cause seasonal
algal blooms.
Figure 4. Real-time water quality and chemical analysis
monitor used in Cedar Lake and Lake Olathe. (Mau, 2004)
Figure 5. (Left) Technician working on the intake structure set up in Lake Olathe. (Right)
Schematic view of intake tower. (Rasmussen, 2005)
Seasonal algal blooms can also endanger some aquatic species and could also be the cause of
the taste-and-odor issues that will be discussed later. They can be caused by excessive nutrient
concentrations, favorable sun and temperature conditions, and presence of pesticides. Data collected
from intake structures (Fig.5) is used for real-time data for water quality. Six trace elements that were
found in the soil samples included arsenic, chromium, copper, lead, nickel, and zinc and all exceeded
the soil-quality guidelines created by the Environmental Protection Agency for some sensitive aquatic
species. Higher concentrations of these trace elements could be more deposited from sediment
transport and accumulation than industrial, agricultural, residential activities in the watershed.
Analysis is still underway and has not found any definitive results on the origin of the excess
phosphorous. Although the source is not defined, it was concluded that the excess phosphorous had
been transported in some way to Cedar Lake and Lake Olathe. Predictions of the seasonal algal
blooms will be the done by monitoring water quality with real-time data using a probe shown in Figure
4. This notification system will be added to the watershed water quality protection plan.
Return to top
Surface Water Quality & Contamination
Every year there is a problem with a taste-and-odor water quality in the Olathe community. In
2000, a study done in cooperation with the City of Olathe, Kansas Department of Health and
Environment, and United States Geological Survey to determine the water quality of Lake Olathe and
the connecting streams. (Mau, 2000 and Mau, 2002) The goal of the study was to better understand
the concentration of chemicals in stream and lake water, the conditions and processes in the lake
watershed, which led to the algal growth and taste-and-odor problems in the drinking water from Lake
Olathe. The concluding action of this investigation was to create a comprehensive watershed
protection plan to be used for the community for maintaining and protecting the water quality in Lake
Olathe.
Ground water quality is well measured in the wells in Olathe, KS. Figure 6 indicates that at 76
m(150 ft.) in the Douglas, Lansing, and Kansas City Groups the water is moderately saline at that
depth. As mentioned previously, the dissolved solids concentrations of the area of concern is very
high.
Figure 6. Table of the stratigraphic unit and the
water quality and well yield that it is associated with. Lake Olathe watershed is associated with the
top unit of this table. (O’Conner, 1971)
Regulatory agencies that are responsible for the protection or cleanup of contaminated waters in
the Lake Olathe Watershed include the United States Environmental Protection Agency (EPA)
Region 7, Kansas Department of Health and Environment (KDHE) Bureau of Water, and the City of
Olathe.
Return to top
Conclusions
The surface water of the Lake Olathe watershed is one of the prominent water sources for both
recreation and consumption. It provides water for agriculture and human use and consumption. High
concentrations of phosphorous and manganese are areas of concern and of current research. Algal
blooms are the cause of the problems of taste-and-odor drinking water in the area. The City of Olathe
is working in cooperation with federal agencies to create a watershed protection plan.
Return to top
References
City of Olathe, 2010. Development in the Lake Olathe Watershed.
http://www.olatheks.org/OMS/LakeOlatheWatershed [retrieved on 29, April 2010].
High Plains Regional Climate Center (HPRCC). 2009. Olathe 3 E, Kansas.
http://www.hprcc.unl.edu/cgi-bin/cli_perl_lib/cliMAIN.pl?ks5972 [retrieved on 29, April 2010].
O’Connor, H. 1971. Geology and Groundwater Resources of Johnson County, Northeastern
Kansas State Geological Survey, The University of Kansas, Bulletin 203.
http://www.kgs.ku.edu/General/Geology/Johnson/ [retrieved on 4, May 2010].
Mau, D.P. 2000. Sediment Deposition and Selected Water-Quality Characteristics in Cedar Lake
and Lake Olathe, Northeast Kansas, 2000. Prepared for USGS with City of Olathe and KDHE.
http://ks.water.usgs.gov/pubs/reports/wrir.02-4073.html [retrieved on 12, April 2010]
Mau, D.P. and C.S. Adams. 2002. The Lake Olathe Watershed – Understanding an Important
Resource. Prepared for USGS from City of Olathe. http://ks.water.usgs.gov/pubs/factsheets/fs.057-02.html [retrieved on 12, April 2010].
Mau, D.P., A.C. Ziegler, S.D. Porter, and L.M. Pope. 2004. Surface-Water-Quality Conditions and
Relation to Taste-and-Odor Occurrences in the Lake Olathe Watershed, Northeast Kansas,
2000−02. Prepared for USGS. http://pubs.usgs.gov/sir/2004/5047/ [retrieved on 11, April 2010]
Rasmussen, P.P. and D.H. McAllister. 2005. Monitoring the Water Quality of Lake Olathe,
Johnson County, Kansas. Prepared for USGS from City of Olathe.
http://pubs.usgs.gov/fs/2005/3093/ [retrieved on 15, April 2010].
USGS. 2009. Water-Quality Study of the Lake Olathe Watershed, Northeast Kansas.
http://ks.water.usgs.gov/studies/qw/olathe/ [retrieved on 11, April 2010].
USGS. 1997. Ground Water Atlas of the United States Kansas, Missouri, and Nebraska HA 730D. Prepared by USGS. http://pubs.usgs.gov/ha/ha730/ch_d/D-text7.html [retrieved on 4, May
2010].
This webpage was designed for Introduction to Hydrogeology
Instructor: Dr. Marcia K. Schulmeister of Emporia State University
For questions or comments contact Liz Coffey
Created on April 30, 2010