1. CARY LAKE HOMEOWNERS ASSOCIATION
Water Quality Issues

2. CARY LAKE Jackson Creek Kahn Pond Storm water discharge pipes
Dam & spillways (2)

3. North End Feb 2012 – Lake down
Trenholm Rd.
Roper Pond & Arcadia Edge Apartments
Dent Middle School
Silt delta
Kahn pond
Decker Blvd.
Old Zorba’s Restaurant
Jackson Creek
O’Neil
New Magistrates Courts 2014
New Elementary
School 2014

4. New Threats – RSCD2 elementary School, Magistrates Courts on Decker, Cardinal Newman School & other construction

5. Cardinal Newman Site

6. Cardinal Newman – Absence of Buffer

7. Richland Elementary Site

8. New Magistrates Courts on Decker

9. Vacant Lots on Cary Lake

10. Siltation Threats North End Cardinal Newman
New Elementary School 2014 – 2015
3. New Magistrates Courts on Decker 2014
4. Kahn Pond
5. Six Storm water discharge pipes
South end
6. Siltation Mounds from Trenholm
7. Potential for development of 12 acres

11. Do Private Lakes Provide a Public Benefit ?
Capture storm water run-off
Reservoir for intense rain events
Repository for silt, trash & pollution
Attract wildlife to urban areas
Aesthetically pleasing to residents
No cost to the public purse

12. What is the Reservoir Effect?
Control lake level to provide reservoir for capture of intense rain events.
Mitigates downstream flooding
If the private lakes were not there then Richland County Storm Water Department would need to provide services for capture of storm water, silt & pollution.

13. RESERVOIR QUESTIONS
Can the level of water in private lakes be managed to provide a “buffer” for intense rain events thereby mitigate downstream flooding?
Can individual lake owners coordinate to provide a controlled level throughout the watershed
Can this be achieved by suitable automatic equipment?
If yes, then does this enable private lakes to apply for public financial support?

14. Depth Gage Installation by GCWA

16. Maintenance Costs
Dam
Fish
Insurance
Landscape & trees
Taxes

17. Maintenance
Addition of fish
Reservoir adjustment

18. Big fish in Cary Lake

19. Cary Lake Dam

20. Dam Maintenance

21. Inside Sluice Box

22. Dredging 50,000 tons removed 2010 – 2011 Cost Approximately $750,000
Paid by Richland County
No cost to CLHA

23. Kahn Pond – Fully Silted
Old Zorbas
Jackson Creek
Old
Dam
Wall
Kahn Pond
Decker
Blvd.
Old Red Lobster
Silt Delta
Cary Lake

24. Kahn Pond
Positions of pictures taken Mar 2013
Bar pushed to full depth into “quicksand”
5 ft long bar
5 ft long bar
Bank of sand carved out by the creek

25. KAHN POND SILTATION
5 foot long
Steel bar

26. North End After Dredging 2011
Creek flowing past Zorba’s and under Decker Bvd.
Kahn Pond
Silt
After dredging 2011 Lake down - Full depth 5 – 5 ½ feet
After dredging 2011 Lake down - Full depth 5 – 5 ½ feet

27. North End – Feb 2013 – Lake down
Kahn Pond
Depth 5ft
Depth 3ft 6in
Depth 4ft 6in
After dredging 2013 Lake down - Full depth 3 ½ – 4 ½ feet

28. Trash behind old Zorbas on Decker

29. Trash in Lake after raising level

30. Storm water pollution Brookfield Rd Water Main burst 02-20-2013

32. Kahn Pond - Turbidity Boom & Trash

33. Kahn Pond & Boom Fourteen months old Wall of old dam in background
detached from base & breaking apart
Wall of old dam in background
is unstable

34. Trenholm End Siltation

35. Large Siltation Mound

36. Lake Catherine

37. Lake Catherine

38. Lake Catherine Siltation

39. Siltation in Lake Catherine
Serious silt after construction of I-77
Eventually dredged by DoT 1993
Completely re-silted by 2010
HoA spent $100,000 on consultants, lobbying
Cost estimated at $980,000
Authorities policy not to dredge private lakes
However, dredging now under consideration with cost share between County, City & FA

40. Lake Issues - Summary Sediment from land disturbances
- RSD2 Elementary School Trenholm Extn./O’Neil
- County Magistrates Courts on Decker
- Commercial developments on Two Notch corridor
- Potential for development of 12 acres at S. end
Trash
Pollution
Sources
- Jackson Creek
- Decker & Trenholm
- six storm-water pipes
- a spillway under Trenholm

41. Summary continued Key question
If the reservoir model works does it open the door for public funding for siltation control?

42. Conclusion
Cary lake is under threat from sedimentation & pollution from storm water run-off
CLHA needs professional advice
CLHA Water Quality Committee has obtained quotes from four consulting organizations
Strategy in the short term is to focus on monitoring construction activity to ensure that codes are enforced
All cost $ & we are seeking grants

43. Water Quality Committee
Chair – Alicia Myhrer
Mark Huguley
Peter Chesney
Hal Thornton
Karl Reinecke
Debbie Robertson

44. Trash Pick-up

46. Richland Elementary Site

47. Quotations & Actions under Review
Consultant review of siltation monitoring methods
- Bathymetric survey entire lake +/- 1inch
- Contours linked to sea level datum
- Interface with dredging contractor drawings
Conventional survey of Kahn pond with lake down
Monitoring of construction discharges
- 2 x private consultants
- US Geological Survey Dept

48. Do Private Lakes Provide a Public Benefit ?
Capture storm water run-off
Reservoir for intense rain events
Repository for silt, trash & pollution
Attract wildlife to urban areas
Aesthetically pleasing to residents
Private lakes deserve public funding support