​October 12, 2020 Lakes Management Implementation Plan- Semi-Annual Review

October 12, 2020
Lakes Management Implementation Plan- Semi-Annual Review
by  Bobby Jones, Interim Director of Facilities

 
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 semi‑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- Construction contractor Docks of the Bay completed construction of Flat Run Forebay June 2020. Since the April LMIP semi-annual review; the gabion wall was constructed. The aluminum frame and filter fabric gate in the gabion wall was fabricated and installed. The extended guard rail was installed. The grass sod, mulch, aquatic planting plugs, and twenty Otto Luyken (laurel shrub) plants were also installed. A staff gauge to access sediment deposition level, used to determine dredging frequency, was installed. Design contractor Stantec Consulting Services was onsite April 29th for project inspection. Surveyor returned and completed as-built survey week of June 22nd. A buoy was installed just downstream of the forebay that reads No motorized boats, Submerged rock wall. Two round floats were installed on the gabion wall, marking the opening where the barge and dredge will travel through when cleanout of forebay is needed. Construction contractor Docks of the Bay was onsite July 6th for a warranty repair to the fabric gate in the gabion wall. The fabric gate came loose during a rainstorm event. An Otto Luyken (laurel shrub) plant in the project area died and contractor was contacted for warranty claim. Contractor installed a matching replacement September 4th.
Construction contractor Finish Line Environmental completed construction of the 14th Pond Retrofit with Forebay July 2019. Since the April LMIP semi-annual review, warranty works were completed. LOWA Environmental Resources Manager hosted a conference call with design contractor A. Morton Thomas & Associates, and construction contractor Finish Line Environmental on April 20th for 14th Pond Retrofit with Forebay warranty claims. Finish Line Environmental agreed to address all warranty claims. Construction contractor Finish Line Environmental made repairs to the Flexamat erosion control slope armoring system, located between the golf cart path and Keaton’s Lake, and addressed all warranty claims in areas of erosion to the channel at the entrance of the forebay, dead and dying plant replacement, and conservation seed mix/wildflower seed mix that did not germinate. The fountain in the fairway pond was installed April 23rd. LOWA Roads Department installed shore armoring (stone) to the entrance channels of the forebay and pond week of September 21st. LOWA Grounds Department installed topsoil, seed, and straw above the stone armoring. Plants and shrubs in the area were trimmed by LOWA Grounds Department.  
LOWA Roads Department removed deposited sediments from Eastover Park Water Quality Retrofit week of August 17th. This is the first of LOWA’s sediment and nutrient reducing best management plan structures to have its deposited sediments removed. Learned experiences will be applied to the future clean-outs of LOWA’s other forebays. Approximately 82 cubic yards of sediment were removed.
  1. Public Education- Articles were written for the Lake Currents newsletter in subjects of lawn care, roadside ditch maintenance, leaf removal, driveway culvert pipe maintenance, blue-green algae and water quality. The Communications Manager and the Environmental Resources Manager maintained/updated a page on our LOWA website for Members to see the safe swimming/water activities status of our Lakes. This page contains the latest bacteriological monitoring testing dates, and safe swimming/water activity status as “safe” or “swimming advisory has been issued” for our lakes. This can be viewed by our Members at https://www.lowa.org/Amenities/Lakes-Marinas/Beach
  2. Dredging- The lake sediment dredge is presently on the Main Lake in Dredging Point #12 (Small/South Marina). Lake sediment dredging was completed in Dredging Point #21 (near Fisherman’s Point/Edgemont Circle), Dredging Point #19 (near Crystal Court), Dredging Point #13 (near 1400 block Lakeview Pkwy), and Dredging Point #14 (near Manassas Point) on the Main Lake, since the last semi-annual review in April. Approximately 1,056 cubic yards of sediment were removed from these Dredging Points.  The typical sediment removal in a six-month period is 1,000 to 1,400 cubic yards. There are 37 dredging points on the Main Lake and 9 dredging points on Keaton’s Lake. Below are the amounts of removed sediment by Fiscal Year. 

                                    
  1. Roadside Ditch Reconstruction/Stormwater Management Program- LOWA Roads Department’s work combined with work of annual contractors yield the following results:

Engineering contractor A. Morton Thomas & Associates (AMT) completed Patrick Henry to Small Marina Drainage Improvement Project 60% design in April. LOWA Stormwater Inspector completed easement acquisition requests to members located in proposed design work areas. Easement acquisitions were signed by five member lots, however, easement acquisitions were declined by two member lots, requiring AMT to revise the intermediate (60%) design. 
The Mt. Pleasant Drainage Project was awarded to construction contractor BZ Excavating. Construction began in October, reconstructing 525-feet of ditch to handle a 10-year storm using geotextile filter fabric and riprap stone. Six driveway culverts were replaced.
The Crossover Pipe Replacement Project was awarded to construction contractor BZ Excavating. Construction began in October with six crossover pipe culverts replaced at various locations. This project replaced culverts located at Mt. Pleasant Drive, Green Street, Lake of the Woods Way, Stratford Circle & Mason Street, Gold Valley Road & Lakeview Parkway, and Forest Court.
Stantec Consulting Services gave a preliminarily assessment of approximately $60,000 for additional study and design for the 100 Monroe Street Culvert Assessment Project.
Construction contractor Greencore installed a stormwater drainage system for Number 10 Fairway Stormwater Management Assessment. This drainage system helps reduce potential flooding of three current houses on Birdie Road and one home soon to be constructed.
  1. Water Quality- LOWA staff completed all annual, quarterly, and monthly water quality testing thus far in FY2020/2021, including nutrient monitoring, physico-chemical monitoring, and bacteriological monitoring.
  2. Aquatic Plant Management- Preliminary Spring Vegetation survey work was completed April 16th to May 1st by the Environmental Resources Manager to identify any potential problem areas. No new areas of concerned growth were observed. The Environmental Resources Manager completed the Fall Vegetation Survey field work September 9th to September 25th. Fall Vegetation Survey Report will be presented to the Maintenance & Ecology and Lakes Committees in January.
B. Works in Progress-
  1. Structural Projects- 14th Pond Retrofit with Forebay – LOWA Buildings Department completed installation of a wiring upgrade for the fountain in the 14th Pond October 15th.
  2. Roadside Ditch Reconstruction/Stormwater Management Program- LOWA Roads Department will continue to reconstruct roadside ditches in need under the direction of the Environmental Resources Manager and the Director of Facilities.
A. Morton Thomas & Associates (AMT) are currently working on the revised, intermediate design for the Patrick Henry Court to Small Marina Drainage Improvements Project. LOWA and AMT are currently waiting for Orange Co. to complete their plat review process regarding drainage easement acquisitions. Design engineer Don Rissmeyer of A. Morton Thomas & Associates (AMT) will be at the October 27th Board meeting to discuss intermediate design to including updated engineering design plans, cost estimates with new phasing, and hydrologic & hydraulic calculations report.
The Mt. Pleasant Drainage Project should be completed October 23rd by construction contractor BZ Excavating. This project reconstructed 525-feet of roadside ditch to handle a 10-year storm using geotextile filter fabric and riprap stone. Six driveway culverts were replaced.
The Crossover Pipe Replacement Project should also be completed October 23rd by construction contractor BZ Excavating. Six crossover pipe culverts were replaced at various locations. This project replaced culverts located at Mt. Pleasant Drive, Green Street, Lake of the Woods Way, Stratford Circle & Mason Street, Gold Valley Road & Lakeview Parkway, and Forest Court.
Stantec Consulting Services gave a preliminarily assessment of approximately $60,000 for additional study and design for the 100 Monroe Street Culvert Assessment Project
Construction contractor Greencore installed a stormwater drainage system for Number 10 Fairway Stormwater Management Assessment. This project is currently under warranty, contractor has been contacted for warranty repairs. This drainage system helps reduce potential flooding of three current houses on Birdie Road and one home soon to be constructed.
The Mt. Pleasant Beach Erosion & Sediment Control Project will begin week of October 19th. A French drain system will be installed, utilizing perforated filter piping, drain tiles, berms, and swales to direct stormwater and mitigate beach sand erosion
  1. Public Education- Environmental articles will continue to be written for the Lake Currents newsletter. LOWA will continue to promote local resources and organizations for members to utilize.
  2. Grant Funding- Additional grants will continue to be sought and applied for to aid in the funding of projects, when LOWA qualifies for available grant funding.
  3. Dredging- Dredging operations will continue in scheduled dredging points on the Main Lake through December. LOWA’s Environmental Resources Manager, Head Mechanic, and Dredge Operator made site visits week of September 21st in research for replacement of 2007 AE-12 Amphibious Excavator. Machinery and methods were studied and compared, and recommendations and general cost estimates were received from Maritime Consultants, successful dredging industry contractors, and Heavy Equipment Dealerships. LOWA is seeking a machine to improve productivity, as well as provide a significant cost savings.
  4. Water Quality- LOWA staff will conduct annual, quarterly, and monthly water quality testing throughout FY2020/2021.
  5. Fisheries/ Habitat Management- Bluegill Sunfish, Redear Sunfish, Black and White Crappie Sunfish, and forage minnows will be stocked in the Main Lake and Keaton’s Lake. Stocking will occur in October.
  6. Aquatic Plant Management- Preliminary spring survey of submerged aquatic vegetation will take place in April/May to identify potential problem areas. Submerged aquatic vegetation fall survey field work will be conducted in September to early October. Creeping water primrose was discovered to be present at the Keaton’s Lake Dam area. Contractor Solitude Lake Management was onsite October 16th for recommendation. Solitude recommends monitoring plant through spring 2021. Applying an herbicide to the plant at this time would not be effective at eradicating the plant, as this time of year the aquatic plants have shut down for winter, and herbicide transfer/uptake is not effective to the root. The plant will continue to brown-out and disappear over winter and likely will reemerge in the spring. If/when it reemerges in the spring, an herbicide can be effective to eradicate in one to two treatments, typically around $1,000 per treatment. The Environmental Resources Manager will continue to monitor and will have treated upon emergence in the spring, after giving notice to members.
C. State of the Lakes-
The following is a brief overview of the health of the lakes as indicated from water quality data collected in 2020/2021.
The Main Lake and Keaton’s Lake typically score well in most water quality standard tests. However, both Lakes do not typically score well when it comes to nutrient level testing for Nitrogen and Phosphorous. Both Lakes typically score poorer than the Environmental Protection Agency’s water quality standards for Total Nitrogen and Total Phosphorous. Our Lakes consistently have an overabundance of nutrients Nitrogen and Phosphorous. An excess in nutrients like Nitrogen and Phosphorous can turn into Eutrophication, which can cause problems like algae blooms and fish kills from low oxygen in the water. While average concentrations of Nitrogen and Phosphorous have improved or maintained relatively the same since the implementation of the 2012 Lakes Management Plan, we still have a way to go. In this time frame, 267 new houses were built in LOW. Every time a new house is built, the majority of the lot becomes impervious to rain and stormwater runoff absorption, as the rain doesn’t absorb into the ground at the lot where the rain falls as it did before, but instead, because the majority of the lot is now covered with impervious surfaces such as the new house, driveway, sidewalk, shed, etc., causes increased stormwater runoff to our Lakes. Increased stormwater runoff brings additional sediments and excessive nutrients like Phosphorous and Nitrogen to our Lakes. Without the implementation of the Lakes Management Plan, suspended sediments in our Lake waters, and Phosphorous and Nitrogen levels would have increased continuously. Our Lakes Management Implementation plan helps mitigate the continued loss of pervious soils due to continued new construction. The Lakes Management Implementation Plan contains multiple pieces that each aid in the overall plan of pollution reduction to our Lakes.
  1. Main Lake- Over the past three years, Total Nitrogen has been higher than the recommended EPA standard of 360 micrograms per liter. During this time, the Main Lake has averaged 2.5 times the EPA standard. Last year, the Main Lake averaged 1.9 times the EPA standard. The four seasonal samplings in FY2018 averaged 1177 micrograms per liter. In FY2019, levels decreased to average 682 micrograms per liter. In FY2020 levels slightly decreased to average 667 micrograms per liter.   Over the past three years, Total Phosphorous has also been higher than the recommended EPA standard of 20 micrograms per liter. During this time, the Main Lake has averaged 2.1 times the EPA standard. Last year, the Main Lake averaged 2.7 times the EPA standard. The four seasonal samplings in FY2018 averaged 43 micrograms per liter. In FY2019 levels decreased to average 38 micrograms per liter. In FY2020 levels increased to average 65 micrograms per liter. (See tables on Page 10.)
  2. Keaton’s Lake- Over the past three years, Total Nitrogen has been higher than the recommended EPA standard of 360 micrograms per liter. During this time, Keaton’s Lake has averaged 3.1 times the EPA standard. Last year, Keaton’s Lake averaged 2.2 times the EPA standard. The four seasonal samplings in FY2018 averaged 1453 micrograms per liter. In FY2019, levels decreased to average 909 micrograms per liter. In FY2020 levels decreased to average 729 micrograms per liter. Over the past three years, Total Phosphorous has also been higher than the recommended EPA standard of 20 micrograms per liter. During this time, Keaton’s Lake has averaged approximately 2.7 times the EPA standard. Last year, Keaton’s Lake averaged 2.6 times the EPA standard. The four seasonal samplings in FY2018 averaged 65 micrograms per liter. In FY2019 levels decreased to average 51 micrograms per liter. In FY2020 levels slightly increased to average 53 micrograms per liter. (See tables on Page 11.)
  3. Both Lakes- Over the past three years, Chlorophyll-a results in both Lakes remain below state threshold levels; no reason for concern.  (See table on Page 12.)
  4. Physical Properties- The Environmental Resources Manager provides the following analysis of physical properties key measures.  (See table on Page 13.)
  • 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 within the standard.  Keaton’s Lake water clarity has improved since the implementation of the Lakes Management Plan.
 
  • 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 lower 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. The dark line separating 12/19/2016 and 5/10/2017, marks the completion of Eastover Park Water Quality Retrofit project. The dark line separating 5/29/2019 and 7/31/2019, marks the completion of the 14th Pond Retrofit with Forebay project. The dark line separating 5/12/2020 and 7/21/2020, marks the completion of the Flat Run Forebay project. Total suspended sediment results, and turbidity results are both lower on average (less cloudy, murky water, which is desirable) since completion of these pollution reducing projects. Secchi Depth results have increased on average (more transparent, clearer water to greater depths, also desirable) since completion of these projects. In 2017, we did not need to treat Keaton’s Lake for harmful blue-green algae, after having at least two algaecide treatments per year from 2013-2016. In 2018, Keaton’s Lake was treated once for blue-green algae. In 2019, Keaton’s Lake was treated once for blue-green algae. In 2020, Keaton’s Lake was treated once for blue-green algae.
 
e.   Outlook - Further improvement of water quality results can be achieved through construction of additional sediment & nutrient removing structures, continued reconstruction of eroding roadside ditches and public education. Public education in maintenance of stormwater drainage ditches which help prevent erosion of soils to our Lakes, the use of only phosphorous-free fertilizer, and help prevent leaves, grass, and pet waste from being an excessive nutrient transported through stormwater runoff in roadside ditches and stormwater drainage ditches on members lots that flow to our Lakes, will continue to be emphasized.
            





  
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
Posted: 11/3/2020 10:29:09 AM by Bobby Jones, Interim Director of Facilities | with 0 comments