April 2017 LMIP Update

Memorandum
To:                  LOWA Board of Directors
 
Thru:               Phil Rodenberg, General Manager
From:              Bobby Jones, Environmental Resources Manager
 
Date:              April 12, 2017
 
Re:                  Lakes Management Implementation Plan- Semi-Annual Review
ISSUE:  Lakes Management Implementation Plan Update.
RECOMMENDATION:  Management recommends the Board continue to provide input and directions on the Lake Management Implementation Plan.
BACKGROUND:  In 2012, the Board initiated a restoration plan to improve the health of the Lakes. The Board approves the Lakes Management Implementation Plan annually in January. Each month the Board is updated on the progress on Lakes Management. Additionally, the Board conducts a semiā€‘annual review in April and October in order to present the progress of implementation to the Community.
 
A. Works Completed to Date-  
  1. Structural Projects- Eastover Park Water Quality Retrofit Project was substantially completed in January. Front Entrance gate, fencing, and plantings were installed in March.
  2. Public Education- Lake Currents - Articles were written for the Lake Currents newsletter in subjects of prevention of transfer of aquatic invasive species and leaf removal. Pamphlets on aquatic invasive species were distributed with annual boat registration. Poster sized informational signs for aquatic invasive species were posted at Member Services.
  3. Dredging- The dredge is presently on Keaton’s Lake. Dredging operations are temporarily halted, awaiting parts for repairs. Lake sediment dredging has been complete in coves K4, K7, K8, K3, and K6 since the semi-annual review last October. 1,120 cubic yards of sediment have been removed from these coves.
  4. Roadside Ditch Reconstruction Program- LOWA Roads Crew’s work combined with work of annual contractors yield the following results:

See Section B.b for 2017 plans.
  1. Water Quality- LOWA staff completed all quarterly and monthly water quality testing for 2016, including nutrient monitoring, physico-chemical monitoring, and also bacteriological monitoring.
  2. Aquatic Plant Management- Vegetation survey was completed this past October. Results for 2016 show 49.1 total acres of submerged aquatic vegetation. In accordance with the Lakes Management Implementation Plan/Schedule 2016-2017, to maintain a multi-use lake, a goal of 5%-15% (25-75 acres) for total SAV has been established. The 2016 survey indicates the lake is inside the target range at 49.1 total SAV acres. Hydrilla growth reduced slightly to 9.7 acres, and will continue to be monitored in the spring survey.
 

B. Works in Progress-
  1. Structural Projects-
  • Flat Run Forebay – Due to site specific construction constraints related to the Rapidan Service Authority water and sewer utilities, the cost to benefit for Flat Run Forebay at this location is not desirable. Projected construction costs greatly exceed budget, while water quality improvement potential would be significantly less (sediment and nutrient removal) than potential pollutant loads listed in the 2012 WEG study/ Lakes Management Plan. Project is on hold and is no longer a high priority.  Next highest priorities are 14th Fairway (Keaton’s) and Culp’s Cove (Main Lake). Flat Run can be re-evaluated when and if an alternative approach is identified by LOWA.
  1. Roadside Ditch Reconstruction- Contractor will complete two miles of ditch reconstruction in September-October 2017. Erosion & Sediment Control Inspector will release a request for proposal in June, and ditch reconstruction will begin in September. Priority area is Ramsay Beach and Stratford Circle to benefit the Main Lake.
  2. Public Education- Environmental articles will continue to be written for the Lake Currents newspaper. Continue to promote local resources and organizations for members to utilize. Rain barrels will be sold at the LOWA Independence Day Celebration event.
  3. Grant Funding- Additional grants will continue to be sought and applied for to aid in the funding of projects.
  4. Dredging- Dredging operations are currently halted, as we await parts for repairs. Upon completion of repairs, dredging operations will continue in scheduled coves in Keaton’s Lake through October.
  5. Water Quality- LOWA staff will conduct monthly and quarterly water quality testing throughout  2017.
  6. Fisheries/ Habitat Management- 2,000 Blue Gill Sunfish and 250 pounds of forage minnows will be stocked in Keaton’s Lake. 3,000 Blue Gill Sunfish and 650 pounds of forage minnows will be stocked in the Main Lake. Stocking will occur the last week of April.
  7. Aquatic Plant Management- Full vegetation survey was completed this past October. Preliminary survey will take place in May to identify potential problem areas.
 
 
C. State of the Lakes-
The following is a brief overview of the health of the lakes as indicated from water quality data collected from 2016.
The Main Lake and Keaton’s Lake consistently exceed EPA water quality standards for Total Nitrogen and Total Phosphorous, which is an ongoing concern.
  1. Main Lake- Over the past three years, Total Nitrogen in the Main Lake has averaged approximately 2.5 times the EPA standard. 2016 quarterly results are lower than 2015 quarterly results on average. Over the past three years, Total Phosphorous in the Main Lake has averaged approximately 3 times the EPA standard. 2016 quarterly results are lower than 2015 quarterly results on average.
  2. Keaton’s Lake- Over the past three years, Total Nitrogen in Keaton’s Lake has averaged approximately 3 times the EPA standard. 2016 quarterly results are lower than 2015 quarterly results on average. Over the past three years, Total Phosphorous in Keaton’s Lake has averaged approximately 3.5 times the EPA standard. 2016 quarterly results are slightly higher than 2015 quarterly results on average.
Over the past 3 years, Chlorophyll-a results in both Lakes remain below state threshold levels; no reason for concern.
Further improvement of water quality results can be achieved through construction of sediment & nutrient removing structural projects, and public education. Public education in the areas of restricted nutrient fertilizers, and leaves/pet waste as excessive nutrient runoff in ditches to the Lakes will be emphasized.

c. Nutrient Levels: (Phosphorus, Nitrogen, & Chlorophyll-α)
 
ML- Average Total Nitrogen Concentrations

 
 
ML- Average Phosphorus Concentrations
 
 
 
KL- Average Total Nitrogen Concentrations 
                                                                                                                                                                                              
 
KL- Average Phosphorus Concentrations

 
 ML & KL- Chlorophyll-α

 

 
 
Physical Properties
 
  •  pH: Within the standards for aquatic life.
  • Dissolved Oxygen: DO levels fluctuate in both lakes as water temperatures change seasonally. DO is at acceptable levels in both Lakes.
  • Temp: Both Lakes are within the acceptable level.
  • Secchi Depth: Main Lake is well within the standard.  Keaton’s Lake water clarity has continued to improve on average over the past 3 years.  
  • Conductivity: Acceptable level for both lakes. General standard for lakes is 50-1500µS/cm. (2014, Teton Science)
  • Turbidity & TSS: Acceptable level for both lakes.  General standard for turbidity is 10-50 NTU (2004, EPA.)  Keaton’s Lake has higher levels on average than the Main Lake; this is expected given the low Secchi Depth readings on Keaton’s Lake.
  • The dark line separating 8/14/2014 and 11/4/2014, marks the completion of the 13th Fairway Stream Restoration Project. Total suspended sediment results, and turbidity results are both lower on average (desirable), since project completion. Secchi Depth results have increased on average (desirable) since project completion. (Clearer, less turbid water)
Posted: 7/3/2017 4:02:10 PM by Ip, Michelle | with 0 comments


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