High Rock Lake

1
High Rock Lake

• Total Maximum Daily Loads

2
Todays Agenda

• Introduction to Use-Support Methodologies and
  High Rock Lake
• TMDL Process
• Scoping Study
• Future Efforts
• Q A

Courtesy CWRC
3
Basinwide Planning Program
Applies to All 17 River Basins

4
Use Support Methodology
Based on Stream Classification
5
Use Support Methodology

• Standards
• Chl a, pH, Dissolved Oxygen, etc.

Aquatic Life

• Standards Met Supporting
• Standards Not Met Impaired
• Inconclusive Data Not Rated
• No Data

6
Current Data (2003 Basin plan)
7
Current Data (2003 Basin plan)
8
High Rock Lake Monitoring History

• 1974 1975 EPA DWQ determine nutrient
  enrichment.
• 1981 UNC-CH documents elevated nutrients and
  chlorophylla concentrations
• 1989 1990 DWQ intensive study
• 1992 1997 2002 DWQ basinwide sampling.

9
Model History

• Early 1990s BATHTUB model
• Estimate nutrient loads
• Determine Assimilative capacity
• Develop predictive tool
• Good loading information
• Good Phosphorous Prediction
• Poor Chla prediction
• Not Sufficient for TMDL purposes

10
Current Data (2003 Basin plan)
High rock map
11
High Rock Lake Impairment

• Upper Lake
• Turbidity
• Low Dissolved Oxygen
• Chla

12
High Rock Lake Impairment

• Lower Lake
• Turbidity

13
High Rock Lake Impairment

• Abbots Creek
• Turbidity
• Low Dissolved Oxygen

14
High Rock Lake Impairment

• Second Creek
• Lake Arm NOT IMPAIRED
• Upstream is impaired aquatic life

15
Everyone has an impact Everyone must be part of
the solution.

• Water quality management is a shared
  responsibility.

16
Basinwide Planning Program Website
http//h2o.enr.state.nc.us/basinwide/or
call919-733-5083