Post on 15-Jan-2016
transcript
Clear Lake WatershedLARE Study Final Public Meeting
Tuesday, November 9, 2010
Why are we here?
Clear Lake Township Land Conservancy applied for a grant to complete an Engineering Design and Natural Resources Assessment in the Clear Lake Watershed
A grant was awarded by the Indiana Department of Natural Resources Lake and River Enhancement
Program (LARE)
Boat license tax
Davey Resource Group was selected to conduct the study along with its subconsultant Engineering
Resources.
What is a watershed?
The total area of land that drains into a particular water body.
Clear Lake Watershed4,419 Acres
Cyrus Brouse Ditch Hoosier Riverwatch Data
146: Cyrus Brouse Ditch 100 ft south of Lake Drive
10/23/2001 Overcast Stormy 8 7.3 2.5 3.5 100.01 0
146: Cyrus Brouse Ditch 100 ft south of Lake Drive
8/28/2008 Overcast Clear/Sunny 7 7.5 - 0 100.01 133
146: Cyrus Brouse Ditch 100 ft south of Lake Drive
11/5/2008 Clear/Sunny Clear/Sunny 7 8.5 - 0 15.01 33
146: Cyrus Brouse Ditch 100 ft south of Lake Drive
4/23/2009 Clear/Sunny Rain 10 7 - 8.8 15.01 0
146: Cyrus Brouse Ditch 100 ft south of Lake Drive
8/17/2009 Showers Storms 7 7 - 15.4 63 567
Site DateCurrent Weather
Past Weather
Dissolved Oxygen (ppm)1
pH1
Total Phosphate
(mg/L)2
Nitrate (mg/L)
Turbidity (NTU)2
E. coli (cfu)1
Cyrus Brouse Ditch Outlet Qualitative Observations: Increased sediment deposition Increased algae and weedy plant growth
What were the Components of the Study?
Locate critical areas in the Cyrus Brouse Ditch Subwatershed that may be contributing to a degradation in water quality
Evaluate the feasibility of projects that could address critical areas in the Cyrus Brouse Ditch Subwatershed
Produce engineered designs for feasible projects
Identify potential critical areas in other subwatersheds
Conduct an inventory and assessment of critical wetlands and natural areas that may influence water quality in the Clear Lake Watershed
Feasibility Study
CLTLC with input from local stakeholders identified potential projects for engineering design to reduce sediment prior to the start of the study
CLTLC along with Davey conducted a windshield survey and walk of Cyrus Brouse Ditch as part of the study Additional potential practices requiring
engineering design as well as numerous, simple and often more cost effective Best Management Practices (BMPs) were identified
Evaluated Engineered Practices Grade Stabilization Structure–Oberst
Property A grade stabilization structure is a structure built
across a drainageway to prevent gully erosion Suspected little sediment and nutrients entering
the ditch from upstream sources in this location Streambank stable in this location Structure had potential to do more harm than
good
Example grade stabilization structure photographhttp://www.wi.nrcs.usda.gov/programs/solutions/gradestabil.html
Stable Cyrus Brouse Ditch streambanks
Evaluated Engineered Practices Water Level Control Structure–Eichler
Property Purpose to pond water in the wetlands for a
slightly longer duration and increase stormwater filtration and denitrification rates
Topographic survey data showed that a structure in this location could exacerbate flooding on CR 500 N
Evaluated Engineered Practices Wetlands–Salsbury Property
Not suitable topographic location for wetlands
Wetlands–Ireland Property Divert additional water into the wetlands
from Cyrus Brouse Ditch Lateral 5 for further filtration and increased denitrification rates
Topographic survey data concluded not feasible
Evaluated Engineered Practices Wetlands/Sediment Pond–Moore Property
Not enough physical area to treat water from upstream watershed
Sediment Pond–Jackson Property Expensive practice, located mid-way in
watershed Determined not to provide enough benefit for the
expense Smaller, less expensive measures can be
implemented to reduce sediment from upstream sources
Evaluated Engineered Practices Two-Stage Ditch–Salsbury Property
Good location in the watershed Pros:
Less maintenance than traditional ditches (lower long-term expense) Reduce bank scour Allow for filtration of sediment and nutrients from storm flow Improves habitat for wildlife New practice and funding is comparably readily available
Cons: Significant excavation may be required Some loss of tillable land
Landowners not interested at this time
Two-stage ditch diagramwww.nature.org
Scour on Cyrus Brouse Ditch bank
Evaluated Engineered Practices
Streambank Stabilization – Marbo Farms Property Originally evaluated as a BMP assuming minimal
design by Steuben County Surveyor’s Office Later determined
engineered design necessary
Design was produced Necessary permits have
been obtained Work expected to begin
anytime by the SteubenCounty Surveyor’s Office
Recommended BMPs BMP = Best Management Practice
Simple, effective, often inexpensive ways to minimize environmental degredation
Grass waterways Vegetated drainage swales in farm
fields where gully erosion is a recurring problem
Scharlach property DeWitt property
Filter strips Bands of sod-forming grasses
panted adjacent to waterways that retard transportation of pollutants
Salsbury property
Erosion is occurring along the south side of County Road 500 North and east of County Road 725 East.
Recommended BMPs Road and roadway ditch repair and
improvements CR 500 North CR 450 North and
725 East
WASCOB Water and sediment
control basin Reduce gully erosion by
controlling flow Trap water and sediment Connected to the tile system Scharlach Property
Sediment and fine particulate matter washes from CR 500 North into the Cyrus Brouse Ditch subwatershed drainage system.
Recommended BMPs
Streambank erosion control Salsbury property – hard armor bank Scharlach property – geotextile fabric
Tile repairs and inlet filters Tile blowouts and
riser inlets without grass buffers allow sediment and nutrients to enterthe tile system
Recommended BMPs
Potential funding sources and cost-share programs for each recommended BMP are included in the study report
Survey of Critical Areas in Subwatersheds A critical area is an area defined as a
source of an identified water quality problem that one is trying to correct
Other areas identified as possible areas that could degrade water quality, but not associated with an identified problem were labeled as an area of concern
Problems identified from Hoosier Riverwatch data High turbidity
Harry Teeters Ditch Alvin Patterson Ditch Peter Smith Ditch
High nitrates Peter Smith Ditch
High E. coli concentrations Alvin Patterson Ditch Harry Teeters Ditch
Critical Areas Tile inlet risers
without grass buffers Contribute
sediment and nutrients
Possible gully erosion (not field evaluated) in a field west of CR 700 East and north of SR 120 Contribute sediment
and nutrients
Critical Areas
Horse pasture on East CR 700 North May be a contributor to elevated E. coli
concentration in the Alvin Patterson Ditch
Areas of Concern
Horse pasture with tile riser inlets south of SR 120
Dumping of yard wastes in wetlands areas around Clear Lake
Sediment built-up within Koeneman Lake which serves as a settling basin on Harry Teeters Ditch
Inventory and Assessment of Critical Wetlands Wetland benefits
Detain and retain stormwater Attenuate flooding Filter sediment and nutreints from water Keep surface water flowing during dry
periods Recharge groundwater aquifers Necessary for many plant and animal
species Benefit tourism and recreational
industries among others
Inventory and Assessment of Critical Wetlands Conducted a remote sensing inventory
Aerial photographs Soil series data NWI wetland maps
Conducted a remote sensing assessment ORAM Categories 1-3
Field evaluations were conducted in some wetlands to verify accuracy of mapping and assessments
Field Evaluations
Hydrology sources and patterns Documented presence of unique
vegetation species Generally scanned areas around lake
for the presence of invasive species Occasional GPS points taken on
wetland boundaries
Conclusions General knowledge helps improve our overall
understanding and interconnectedness of the area in which we live and operate
Gives baseline data for making educated decisions in relation to future land development
Approximately 336 acres of wetlands 99 total wetlands Mapped boundaries have an estimated accuracy of ±50
feet 14 wetlands are Category 3, best wetlands 7 wetlands have a direct surface connection to the lake 15 wetlands are connected to the lake via a county tile
Conclusions
No new imminent invasive species threats discovered
2 wetlands contained numerous uncommon, high-quality vegetation species and have high conservation potential
A portion of Wetland 11 is a sedge meadow dominated by Carex stricta (uptight sedge).
Wetland 90 had some unique wetlands species including Betula allegheniensis (yellow birch), Larix laricina (American larch), and Toxicodendron vernix (poison sumac).
Wetland 97 contained numerous unique wetlands species having high coefficient of conservatism values including Betula allegheniensis (yellow birch) and Osmunda cinnamomea (cinnamon fern).
This photograph depicts Vaccinium corymbosum (highbush blueberry) that was observed in Wetland 97.
Final Report
Further details on potential project funding sources, water quality data interpretation, critical areas, areas of concern, and the inventory and assessment of wetlands can be found in the project report
Draft report is currently available http://www.in.gov/dnr/fishwild/3303.htm
Final report will be available soon DNR website CLTLC website
Thank you for comingand for your support in
maintaining and improving water quality in the
Clear Lake Watershed!