Period Covered:
From: 1 May, 2000
To: 30 June, 2005
ARTICLE I. Statement of Contract Purpose:
To provide the Iowa
Department of Natural Resources (referred to below as IDNR)
with a lake database, including water chemistry, biological analyses
and watershed GIS. This database will have many uses (e.g., lake
classification for restoration, water quality evaluation, monitoring)
and will follow-up on similar surveys published in 1980 and 1994.
ARTICLE II. Description of Work and Services:
1. Overall Explanation of Specific Objectives
The objective of this program is to sample 132 of Iowa's principle
recreational lakes, and to characterize current water quality
and watershed characteristics. Because temporal variation in Iowa
watersheds is great, a five-year study is planned to yield a stable
and reliable assessment of Iowa lakes and lake watersheds. Each
lake will be sampled three times during each of the five study
years. Analyses will be designed to create a more powerful database
that will be comparable with previous decadal assessments of Iowa's
lakes (Bachmann et al. 1980, Bachmann
et al. 1994).
2. Study Principles
- All of Iowa's lakes will be sampled on the same time frame
to improve comparability.
- Samples will represent open water mixed-zone.
- Same parameters will be estimated as in previous surveys but
with added information anticipating future data needs as well
as increased levels of precision.
- E.g., pigment profile, algal composition, paleolimnological
P history, zooplankton stoichiometry, alternate geochemical
information.
- Funding will support data collection, creation of Lakes 2000
database, and mainstream science.
- Activities will be housed within Iowa
State Water Resources Research Institute (ISWRRI) at ISU.
- Analyses will integrate an unprecedented degree of detail
and quality control.
3. Limnological Sampling and Analysis.
A list of 132 of Iowa's lakes (see list in appendix
I) will be sampled three times each year. Three sets of samples
will be taken in each lake in each year. Sampling times will be
arranged that represent (1)spring-early summer, (2)mid-summer,
and (3)late summer-fall. Samples will be taken at one site in
each lake basin, chosen to represent the open-water zone. Up to
three sampling sites will be examined in a few of the largest,
most meandered lakes. Two field teams will travel throughout the
state collecting triplicate water samples representing the upper
mixed zone of each lake. These samples will be analyzed for a
number of analytes (see Table 1, column
1). Preceding sampling, depth profiles of several analytes (see
Table 1, column 2) will be determined using
remote analytical transducers. Field teams will use temperature
profiles to determine the depth of the upper mixed layer. This
sampling scheme has been chosen to ensure comparability with previous
surveys (Bachmann et al. 1980, Bachmann
et al. 1994). Water clarity will also be determined by Secchi
disk, and integrated mixed-zone samples of phytoplankton and zooplankton
will be collected using an integrated column sampler. Phytoplankton
and zooplankton composition and size distribution will also be
determined microscopically. Silt and potential settling velocities
will be determined by analyzing particle size distributions in
situ or in the laboratory, depending upon availability of equipment.
Contingent upon availability of equipment (equipment cost not
budgeted here), geochemical elemental profiles of water samples
will also be determined using ICP-MS.
4. Bathymetric Analysis.
Each lake will be mapped by the engineering unit of DNR
during the five-year course of the study. Providing that data
can be received from IDNR
in a compatible and analyzable form, bathymetric coverages will
be analyzed for principal bathymetric variables, e.g., hypsography,
area, mean depth, maximum depth, volume, shoreline development,
watershed/lake area ratio, and shoreline length.
5. Pesticides, Herbicides and Metals.
Sediments and water samples will be collected once per year
from a single site in each lake (except as noted above for large,
meandered lakes) and shipped to University Hygenic Laboratories
to be analyzed for a cross-section of critical pesticides, herbicides,
and metals. Reference sediment samples will be stored frozen at
-80°C for future screening of currently unmonitored hazardous
substances.
6. Watershed GIS.
Geographical information systems (GIS) will be used to prepare
coverages for the watersheds of each of the lakes sampled. Coverages
will be obtained from IDNR
and IGSB GIS units, and will be summarized to indicate the proportion
of each watershed in specific land-use categories (see a higher
resolution example at the following website: http://limnology.eeob.iastate.edu/Studies/RockCreekLake/Rcwin/FIGURE11.html).
Digital elevation models (DEMs) and digital soils data will be
analyzed for geographical combinations of slope, soil and land-use
that are prone to erosion or nutrient efflux. Recent aerial photographs
will be analyzed to indicate the presence of buffering land-uses
and signs of erosion in fields and within water, where possible.
DEMs will be analyzed to divide the watershed into its main sub-watersheds,
and land-use categories will be quantified within each of these.
7. Ancillary Data Collection.
The final report will contain information on lake use classifications,
lake use rates, fisheries information, point and non-point pollution
sources, and perceived impairments, as per Bachmann
(1994). These ancillary data will be obtained from IDNR,
except where they can be derived directly from the analyses of
the data collections described above.
8. Products
- Full lake survey with all lakes comparable.
- Preliminary report by late winter 2000-2001.
- Annual reports of each year's data collection.
- ArcView™ GIS coverages of all watersheds.
- Full profiles of many chemical and physical parameters.
- Web-based database.
- Basic watershed/lake science, e.g., watershed/water chemistry
analyses to support other programs (e.g., TMDL, 30-lakes choice)
9. Reports
- ISU will
provide IDNR
with 10 copies of the written report in each year.
- ISU will
distribute copies of the report to the community at a moderate
cost.
References
Bachmann, R.W., M.R. Johnson, M.V.
Moore and T.A. Noonan. 1980. Clean lakes classification study
of Iowa's lakes for restoration. Final Report. Iowa Cooperative
Fisheries Research Unit and Department of Animal Ecology, Iowa
State University, Ames. IA. 715 p.
Bachmann, R.W., T.A Hoyman, L.K. Hatch,
and B.P. Hutchins. 1994. A classification of Iowa's lakes for
restoration. Final Report, Iowa Department of Natural Resources,
Des Moines, IA. 517 p.
Click
to see Appendix I.
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