Lake Holiday Lake Management Plan

2018 CONTENTS

2018 LAKE HOLIDAY LAKE MANAGEMENT PLAN ...... 4 DESCRIPTION OF LAKE AND COMMUNITY ...... 5 GOALS FOR THE LAKE ...... 5 VEGETATION: ...... 5 FISHERIES MANAGEMENT: ...... 6 WATER QUALITY: ...... 6 SHORELINE EROSION CONTROL: ...... 6 WATERSHED MANAGEMENT/SEDIMENT CONTROL: ...... 6 SEDIMENT REMEDIATION: ...... 6 BASIC LIMNOLOGY ...... 7 ACTION ITEMS ...... 9 VEGETATION: ...... 9 PROBLEM: ...... 9 BACKGROUND: ...... 9 ACTIONS TAKEN: ...... 10 PROPOSED FUTURE ACTIONS: ...... 10 FISHERIES MANAGEMENT: ...... 11 PROBLEMS: ...... 11 BACKGROUND: ...... 11 ACTIONS TAKEN: ...... 12 PROPOSED ACTIONS: ...... 12 WATER QUALITY ...... 13 PROBLEMS: ...... 13 BACKGROUND: ...... 14 ACTIONS TAKEN: ...... 16 FUTURE REQUIRED ACTIONS: ...... 20 WATER QUALITY PARAMETERS: ...... 23 FUTURE PROPOSED ACTIONS: ...... 30 SHORELINE EROSION: ...... 31 PROBLEM: ...... 31 ACTIONS TAKEN: ...... 32 PROPOSED ACTIONS: ...... 32 WATERSHED MANAGEMENT/SEDIMENT CONTROL: ...... 32 PROBLEM: ...... 32 BACKGROUND: ...... 32 ACTIONS TAKEN: ...... 34 PROPOSED FUTURE ACTIONS: ...... 41 SEDIMENT REMEDIATION: ...... 42 PROBLEM: ...... 42 BACKGROUND: ...... 42 PROPOSED FUTURE ACTIONS: ...... 43 CONCLUSION ...... 44

2018 LAKE HOLIDAY LAKE MANAGEMENT PLAN

The Board of Directors passed a resolution in 2015 acknowledging that the lake is a common area and a capital asset of the Association. This makes it the responsibility of the Association to reasonably preserve, maintain and, where necessary, repair the lake. These responsibilities are handled through a Lake Management Plan (LMP) prepared by the Lake Committee and approved by the Board. The LMP provides a framework for the Association to identify issues with the lake, identify viable solutions, estimate the cost of those solutions, implement actions to achieve the solutions and keep track of the success of actions taken. The LMP also helps the Board make strategic budget decisions concerning the lake.

The LMP is a fluid document designed to identify and implement plans to protect and maintain desired conditions within the lake body and its watershed for a given period of time (usually a rolling 5-10 year period). The LMP should be updated on a periodic basis, so that the condition of the lake is continuously assessed and appropriate action plans put in place. During the initial years of the LMP, the focus of the LMP typically will be on problem identification and information gathering. Action items in the early years will be directed at defining and quantifying problems through studies and expert consultation. As studies are performed and problems become more well-defined, the LMP will offer considerations for progressing toward more informed strategies. As recommendations are carried out, data will be added to the LMP that will help determine future actions to be initiated.

The first Lake Holiday LMP was approved by the Board in 2015 (the 2015 Plan). The areas of concern identified in the 2015 Plan were:

1. Invasive aquatic vegetation 2. Quality of fishery 3. Water quality 4. Shoreline erosion 5. Watershed management 6. Control of sediment accumulation and removal

These continue to be areas of concern to be addressed in this revised LMP (the 2018 Plan). However, as more information has been gathered through studies and testing these areas of concern have been clarified and fleshed out.

1. Control of invasive non-native vegetation, renewal of native vegetation 2. Fish stocking, especially of small mouth bass and filter fish, fish habitat for small fry 3. Control of potentially toxic blue-green algae, minimize growth of green algae, monitor/locate/correct sources of e.coli bacterial contamination, manage internal nutrient loading and minimize further eutrophication 4. Control run off from shoreline of sediment/phosphorus during rain events 5. Control sediment and phosphorus coming into lake from tributaries and watershed 6. Minimize sediment build up to maintain boating channels in tributaries and performing sediment removal as required

The 2018 Plan establishes the goals for each area of concern, sets forth the perceived problem(s) in each area, gives historical data and past actions for addressing the problems, provides methodology for reaching solutions to the problems and recommends future actions for each area of concern.

DESCRIPTION OF LAKE AND COMMUNITY

Lake Holiday is a 240 acre man-made privately owned lake located in Cross Junction, Frederick County, Virginia, in the middle of Lake Holiday Country Club. Lake Holiday is approximately 15 miles northwest of Winchester, Virginia and one mile southwest of the eastern border of Hampshire County, West Virginia.

The lake is the centerpiece of Lake Holiday Country Club, a 1900 acre community. The community consists presently of 950 homes, 1,200 undeveloped lots and common areas with amenities such as beaches, a marina and a clubhouse. The lake is used for numerous recreational purposes, including power boating, water sports and fishing.

The lake was created from the riverbeds of Isaac Creek and Yeider's Run. An earthen dam was built in 1970 and the lake filled up in 1972. The spillway for the dam was rebuilt in 2013 to meet current Virginia regulations to accommodate higher rainfall events. The lake has numerous coves and varies in depth. The coves typically are 4’ to 30’ deep in the middle, and the lake is approximately 90 feet deep near the dam.

Approximately 1000acres of the community are undeveloped and consist of forests and grassy fields and are expected to remain that way for the foreseeable future. The lake is not used as a reservoir or water supply for any area. Lake Holiday’s watershed is very large, 8,497 acres, which is primarily farmland. The watershed, through the tributaries, contributes 1.5 million pounds of phosphorus-laden sediment into the lake each year.

Since the creation of the new spillway and because the lake is man-made, very deep, and has very steep slopes, very little water and no sediment leaves the lake except during significant storm events. Therefore “what comes into the lake stays in the lake”. The community has come to understand the critical importance of this and the need to manage the water quality of the lake as it ages.

GOALS FOR THE LAKE

AQUATIC VEGETATION:

• Encourage growth of native vegetation, while keeping them below a nuisance level. • Control invasive vegetation: hydrilla and brittle naiad. • Introduce vegetation that is carp resistant and will capture phosphorus entering the tributaries • Educate community about preventing the introduction of hydrilla on boat hulls and engines

FISHERIES MANAGEMENT:

• Maintain a balanced quality fishery through proactive habitat, restocking, harvesting and best management practices. • Provide opportunities for successful catch rates of a variety of species of fish.

WATER QUALITY:

• Maintain health of water for swimming, fishing and recreational activities • Maintain water quality and clarity by preventing nutrient loading • Prevent or retard development of excessive algae growth • Prevent or retard development of toxic blue-green algae • Monitor bacteria levels weekly during the season and inform community if there is a high level of e.coli in the main body of lake • Educate community about health issues caused by high levels of bacteria or toxins • Locate, monitor, and investigate controls for sources of bacterial contamination including overflowing lift stations owned by Aqua

SHORELINE EROSION CONTROL:

• Control sediment and phosphorus entering lake through storm events • Educate community about ways to minimize shoreline erosion and rainfall runoff including shoreline plants and riprap

WATERSHED MANAGEMENT/SEDIMENT CONTROL:

• Control and manage the 1.5 million lbs. of new sediment and phosphorus accumulation within and entering the lake and tributaries. • Implement best management practices (BMPs) by dissipating energy of streamflow and capturing and removing a portion of sediment and phosphorus before they enter the lake • Educate community about BMPs and how to minimize sediment and phosphorus entering lake • Longer term partnering with landowners upstream of LHCC property to encourage best management practices on agricultural land.

SEDIMENT REMEDIATION:

• Remediate areas of high sediment accumulation if required to maintain boating channels • Remove sediment as required for creating BMPs for sediment and nutrient control

BASIC LIMNOLOGY

Limnology: the study of the physics, chemistry, and biology of freshwater lakes and reservoirs.

Trophic State Index (TSI): a number classification system (0-100) designed to rate lakes based on the amount of biological activity they sustain. It looks at three variables: total phosphorus (TP), chlorophyll a, and Secchi transparency (SD). Between TSI 40-50 TP doubles in concentration and SD halves, a change that would be obvious to lake users in loss of transparency and green/brown coloration. The quantity of nutrients such as phosphorus and nitrogen and other chemicals from the watershed entering the lake, together with factors such as temperature and light, affect the abundance of algae production in the lake. Production, in turn, affects the entire biological structure of the lake. Lakes become more productive as they age. Oligotrophic lakes are those with low production, “never leading to a coloring or even a clouding of the water.” In hypereutrophic lakes, production attains very high values, “the water being, for the most part, very strongly clouded or even completely colored.”

Eutrophication: the water quality deterioration process whereby the loading of nutrients such as phosphorus and nitrogen and the loading of silt and organic matter into the lake is at a rate sufficient to increase the potential for high biological production of algae, decreased basin volume, and depleted dissolved oxygen thereby affecting the health of lake organisms and the water quality. Low lake flushing rate is also an important factor that promotes eutrophication. Eutrophic lakes have colored water (green/brown).

Thermal stratification/thermocline: the formation of three temperature-driven water layers during summer and winter months. In summer the layers consist of an upper warm well-mixed zone termed the epilimnion. Below this is a zone of rapidly decreasing temperature with depth, the metalimnion, followed by a deep, colder, often dark bottom layer, the hypolimnion. This phenomenon, brought about by wind mixing, solar input, and by large differences in water density between cold and warm waters, is a primary determinant of summer physical, chemical, and biological interactions. During winter months lake water temperature inversely stratifies, with colder water at the surface. Lakes with two mixing periods (spring and fall) and two stratified periods are dimictic and are typical of deep lakes of north temperate latitudes.

Anoxia/DO depletion: low to no oxygen conditions typically in deep water areas of the lake during thermal stratification. Anoxic conditions provide conditions favoring high rates of nutrient (phosphorus) release from sediments to the water column. During thermal stratification, deep water does not permit light penetration for photosynthetic oxygen generation. Respiration by organisms in deep water leads to dissolved (DO) oxygen depletion or elimination, to reducing conditions, and to the associated release of P from sediment-iron complexes. Summer winds force vertical entrainment of P-rich deep water to the surface stimulating algae blooms.

Limiting nutrient: the “food” in shortest supply relative to the demands by algae. This is most frequently phosphorus (P). P does not have a gaseous phase so the atmosphere is not a significant source, unlike nitrogen or carbon. Lake P concentration, therefore, can be lowered significantly by reducing loading from land and lake sources.

Internal nutrient loading: arises from aerobic and anaerobic sediments, groundwater seepage, decomposing macrophytes, sediment resuspension, and organism activities (sediment disturbance by fish and insects) that are within the lake. Oxygen depletion in the hypolimnion (deep water) leads to nutrient release from sediments which can vertically migrate up the water column and serve as food to create algae blooms.

External nutrient loading: nutrient inputs to the lake from the watershed that arises from erosion of stream banks during stormwater events, agricultural runoff (P-laden fertilizers and manure), urban runoff from impervious surfaces that enter the water during storm runoff.

Wetland-Littoral zone: the shallow, well-lighted stable sediment area of a lake. Physical factors, particularly waves, transparency, and the slope of this area are among the determinants of maximum macrophyte biomass and maximum depth of plant colonization. The littoral zone often has high species diversity, and is commonly the site where fish reproduction and development occurs. It is also an important waterfowl habitat. Littoral zone plant biomass replaces itself two or more times per summer in productive lakes leading to inputs of non-living dissolved and particulate organic matter to the water column and sediments. Therefore lakes are strongly linked to the land, not only through nutrient and silt loading, but through these organic matter inputs.

Biotic communities: lakes have three distinct and interacting biotic communities: the wetland- littoral zone and its sediments, the open water pelagic zone, and the benthic or deep water profundal zone and its sediments. Problems appearing in one zone (deep water oxygen depletions, littoral zone aquatic plants, pelagic zone algae blooms) directly or indirectly affect other zones. For example, nutrients causing algae blooms may come from lake sediments and decomposition of littoral plants, as well as from external loading. All sources may require attention to solve problems. Plankton, including algae, bacteria, fungi, Protozoa, and filter- feeding crustaceans like Bosmina and Daphnia dominate the pelagic zone which obtains its energy from sunlight and the detritus transported to it from stream inflows and the littoral zone. The profundal benthic community receives nutrients and energy from organic matter loaded or produced in the lake and deposited on the sediments. In productive lakes, large areas of the sediment community in deep water are continuously anoxic during thermal stratification due to intense microbial respiration that is stimulated by deposits of organic matter.

Macrophytes: rooted emergent, floating, and submersed vascular plants that dominate the wetland-littoral zone. Macrophytes, in addition to being a significant energy source and habitat, stabilize littoral zone sediments from the impacts of wind and boat-generated waves, thus reducing internal phosphorus loading and sediment resuspension.

Phytoplankton: microscopic, floating plant cells, colonies, and filaments of algae often seen as surface scums in eutrophic systems. Macrophytes may have large masses of filamentous (string or hair-like) algae attached to them as thick mats. Shallow lighted sediments often have a highly productive flora (algae growing on surface rocks, sediments, and vascular plants). Macro and micro-plankton, and the fish and invertebrates grazing on them, dominate the pelagic zone. The plankton of most eutrophic lakes is dominated by one or a few species of highly adapted algae and bacteria, particularly nuisance blue-green algae (cyanobacteria).

ACTION ITEMS

AQUATIC VEGETATION:

PROBLEM:

In August 2013 invasive vegetation (hydrilla and brittle naiad) was found in the lake at several locations. Invasive vegetation can rapidly overwhelm the natural ecosystem. The loss of native vegetation can prevent fish spawning and reduce the amount of oxygen in the water to the detriment of robust aquatic species.

BACKGROUND:

An initial 100 point survey performed in August 2013 located, identified and quantified the species of vegetation in the lake. The survey determined that there were invasive species of vegetation in the lake. These included hydrilla and brittle naiad. These plants rapidly take over the lake preventing native species from getting enough light, clogging boat motors. The most likely source of these invasive vegetation species was from boats that had been used elsewhere and not cleaned properly before being relaunched in Lake Holiday.

After extensive research online, discussions with stewards of other lakes in Virginia and North Carolina with invasive vegetation problems, meetings with Solitude Lake Management and DGIF and evaluation of costs, the Lake Committee recommended to the BOD that 540 12 inch sterile grass carp be introduced into the lake to control the invasive vegetation. The cost for the carp was $7,630 ($14.00 per fish).This action was approved and implemented in the spring of 2014.

DGIF and Solitude recommended a survey a year after carp introduction to determine their efficacy in controlling the invasive vegetation as well as their potential effect on native vegetation. It is important to evaluate vegetation coverage so there is not an impact on the fishery in future years.

A more comprehensive study to map the extent of all the vegetation species in the lake and to estimate percentage coverage may be recommended in the future depending on the results of the second survey and the determination of future goals.

The survey itself is performed along the shoreline of the lake in August/September. It involves three rake tosses performed in each of the 100 predetermined sampling locations from the 2013 survey. Where vegetation is present, the density will be estimated. A report will be provided that includes a map of survey points identifying the vegetation present, an overall summary of the field observations and data collected, and recommendations as necessary. No further vegetation surveys have been performed due to total eradication of all vegetation in the lake after one year of grass carp.

ACTIONS TAKEN:

ACTION #1:

August 2013: aquatic vegetation survey: discovered invasive plant species hydrilla and brittle naiad in multiple locations.

ACTION #2:

Research performed; DGIF and Solitude Lake Management recommended sterile grass carp as the first line of defense. Recommended to BOD to release 540 12” carp into the lake at a cost of $7,630. This action was implemented in 2013.

ACTION #3:

VDGIF was contacted in early September 2015 for recommendations after invasive species and all other vegetation were eaten by sterile carp. VDGIF advised that: (A) lack of vegetation is a good sign; (B) bass in the lake don’t need vegetation to spawn as the lake has lots of downed trees and rocks for spawning beds; (C) Grass carp eat less as they grow and don’t reproduce. Unfortunately they can live for up to 10 years with a 10-30% die off rate each year.

PROPOSED FUTURE ACTIONS:

ACTION #1:

Hire contractor to perform carp exclusion zone experiments during 2018 or 2019. This involves building underwater fences in select shallow cove areas to keep grass carp out and allow aquatic vegetation to naturally return. Aquatic vegetation will be carefully monitored to determine what types of vegetation return naturally, with the goal to encourage beneficial native vegetation and discourage invasive species.

ACTION # 2:

An SAV Management Plan will be developed as part of these experiments to include management measures (mechanical harvesting, chemical controls, etc.) and possible planting of native aquatic vegetation where necessary to act as a BMP to remove sediment and phosphorus from major tributaries.

FISHERIES MANAGEMENT:

PROBLEM:

VDGIF surveys indicate there has been a significant reduction in the number of smallmouth bass in the lake. Lack of vegetative cover in the littoral zone plus lake drawn down to build the new spillway in 2013 has had a detrimental effect on reproduction and development of young fish and limiting their ability to hide from larger predators and has significantly altered shallow water habitat. The present fish population is aging and dying off and restocking has not occurred in many years.

BACKGROUND:

Sport fishing plays an important role at Lake Holiday. Ongoing surveys, monitoring and management of the fish population are required.

Because anglers fishing in Lake Holiday are required to have a Virginia Freshwater Fishing License, VDGIF surveys the lake and provides management recommendations. Electrofishing surveys (4 samplings at 15 minutes each) were conducted in 1999, 2003, 2009, 2014 and 2017. These reports are available on request. Lake electrofishing surveys are conducted at night in the spring when fish are more likely to be in shallow areas.

The VDGIF surveys show that smallmouth bass comprised 50% of Lake Holiday’s black bass population in 2009, population totals declined to 29% in 2014 and during 2017, this total fell to 6%.

Several factors have impacted the habitat/success of this specific fishery including the 10-12’ lake draw down during dam construction, the age/mortality of our larger/mature spawning class fish and the stocking of sterile grass carp. The grass carp eradicated the vegetative/grass cover necessary for young of the year class smallmouth to hide/evade predators while reaching a sustainable size and the lake draw down significantly altered the shallow water habitat necessary for productive spawning.

VDGIF has recommended stocking of 3”-5” smallmouth during the next several years, monitoring/placement of additional forage base (minnows, crayfish, etc.) ongoing placement of artificial habitat cover, until such time that native vegetation returns to the lake, and continued fish surveys to monitor the health of all species, but in particular Lake Holiday’s smallmouth bass population.

Current fish species include Largemouth Bass, Smallmouth Bass, Striped Bass, Bluegill, Yellow Perch, Channel Catfish, Yellow & Brown Bullhead Catfish, White Sucker, Creek Chub, Sucker, Grass & Common Carp, Green Sunfish, Redbreast Sunfish, and Chain Pickerel.

The forage base includes bluntnose minnow, golden shiner, alewife, and crayfish.

ACTIONS TAKEN:

ACTION #1:

In 2017and 2018 volunteers purchased materials, constructed and placed artificial habitats including milk crate structures and artificial plant reefs to increase survival rates for young of class fry. Interested LHCC members may contact the Lake Committee if they wish to participate in this program. Funds for additional habitat placement in 2018 has been approved.

ACTION #2:

Volunteers participated in bow fishing in 2017 and 2018 to eliminate sterile grass carp to restore natural vegetation. Grass carp are very difficult to catch using typical methods of fishing. Bow fishing was done off boats with spotlights late at night. This activity was moderately successful.

ACTION #3:

Approval was obtained to implement small mouth bass stocking in 2018. It has been difficult to find a fishery that stocks large enough young fry thus this action has not been completed. Volunteer donations and association funding will go towards restocking efforts. Anglers and VDGIF biologists are continuing to meet to make educated decisions on specific fish species, suppliers, time of year, & possible forage to stock.

ACTION #4:

New creel limits were developed and approved and signage has been posted at the marina and dam parking areas to notify members of LHCC’s Catch & Release Requirements & Creel Limits on the type/number of certain fish species that can be harvested:

• Largemouth, Smallmouth, & Striped Bass = catch & release only • Bluegill/Sunfish = No Length Limit & 50 per day • Catfish = No Length Limit & 25 per day • Yellow Perch = No length limit & 20 per day

ACTION #5:

Documents have been drafted for an approval process for all fishing tournaments held on Lake Holiday waters. This will regulate the total number of tournaments, time of year, culling tags, limits, slots, and fizzing techniques.

PROPOSED ACTIONS:

ACTION #1:

Improve habitat through continued strategic placement of milk crate and artificial plant reefs, deep water rock piles and/or other VDGIF approved habitat structures. ACTION #2:

Reintroduce native non-invasive vegetation and manage vegetation in wetland/littoral zone of the lake.

ACTION #3:

Introduce spawning beds.

ACTION #4:

Implement additional restocking of various fish species and forage fish that may include crappie, trout, striper, smallmouth, walleye through consultation with anglers at Lake Holiday, VDGIF, and possibly private lake management companies.

ACTION #5:

Evaluate health of fishery to make determination on harvesting a slot limit on largemouth bass and more aggressive harvest for panfish species that are overpopulated and growth stunted.

ACTION #6:

Continue VDGIF electrofishing surveys every 3 years.

ACTION #7:

Develop a record keeping system for smallmouth and largemouth bass numbers.

ACTION #8:

Designate clean up (trash pickup) days on land and water once or twice a year.

ACTION #9:

Establish specific annual budget and capital improvement funding requests for all aspects of the fishery management program to supplement the donations/work of volunteers.

WATER QUALITY

PROBLEMS:

• During heavy rainfall events, especially in the summer season, high levels of harmful bacteria (e. coli) can be found in the lake due to excessive run off. • On occasion there are overflows of sewage from lift stations and grinder pumps into the lake leading to high levels of harmful bacteria near those locations. • Agriculture, manure and aging septic fields outside of Lake Holiday also contribute to high levels of harmful bacteria in the lake through the tributaries. • Depending on weather events/water temperature/dissolved oxygen levels in the water and the season of the year, the phosphorus levels in the sediment and the water column may become elevated and produce excessive algae growth that may include toxic blue-green algae. • There has been a lack of consistent and thorough water quality monitoring which only began in the 2000’s. Therefore it has been difficult to determine historical trends in water quality as the lake ages.

BACKGROUND:

Water quality is an extremely important measurement of the health of the lake. Data is required to determine the chemical composition of the lake to assess organic pollution, potential for overall health of fish and other aquatic species and water clarity.

E.coli bacteria testing are performed weekly throughout the recreational season at several locations throughout the lake and tributaries then taken to Shenandoah University for analysis. If levels of the bacteria are above EPA recommended standards, 235 e.coli CFU/100 ml in freshwater, then advisories are posted to inform the community of the hazardous conditions. Depending on the location or locations that test above the EPA standard, certain areas or the entire lake is posted as no swimming. These levels on occasion rise above normal after heavy rainfall events in the summer months.

E.coli testing has been done by Lake Holiday since it was sold to Aqua in 2006. It is typically taken at 4-5 stations throughout the lake, including Beach 1 and Beach 2. Members of the Administrative Staff and volunteers from the Lake Committee have been trained by Friends of the Shenandoah to take the samples, record information and maintain a chain of custody for the samples. The samples are then delivered to the FOS lab at Shenandoah University where they are analyzed. The process from delivery to FOS to when Lake Holiday is notified of the results takes about 24 hours. If Lake Holiday is notified that an area or areas exceed the EPA guidelines, then a retest of the area affected is taken as soon as possible, or weather conditions permit.

Water quality data for Lake Holiday has been historically collected by Friends of the Shenandoah River (FOS) and various environmental consultants over the past several years.

Water quality data collected via FOS details various nutrient data throughout the lake, at various intervals, dating back to 2009. This data included various water quality parameters including nitrate, orthophosphate, ammonia and turbidity. It is important to note that total phosphorus was not measured during these events. This data does not provide significant insight into the phosphorus dynamics and trophic state of the lake.

Some data provided by FOS, namely dissolved oxygen and nitrogen parameters, may offer some limited insight into nutrient cycling in the lake at the time of sampling. Specifically, dissolved oxygen concentrations showed deep water anoxia during the 15 August 2011 and 15 October 2015 sampling events. During these events, a disparity between surface and deep-water ammonia and nitrate concentrations was observed whereby higher deep-water concentrations of both nitrogenous parameters were identified. As such, internal loading of P, which commonly mirrors increasing deep water ammonia concentrations under anoxic internal loading situations, may have occurred.

Additional water quality data were also collected by environmental consultant SOLitude Lake Management on 24 July 2014, 28 October 2016 and 16 May 2017. Data collection during these events varied but typically included at least in-situ measure of temperature and dissolved oxygen. Discrete laboratory parameters were also analyzed, including total phosphorus (TP) and ‘free reactive phosphorus’ which is akin to measure of ‘soluble reactive phosphorus (SRP).

In-situ measures on 24 July 2014 were taken at an area of the lake characterized by a maximum depth of 30’. This profile showed thermal stratification and reductions in DO with depth to a minimum of 4.40 mg/L at 30’. Given that the maximum depth of the lake is approximately 85 to 90’, this data does not provide an accurate representation of whole lake stratification at the time of sampling. Data collected during the 28 October 2016 event included temperature and dissolved oxygen readings taken at several stations throughout the lake. During this event, temperatures were mixed and oxygen readings were acceptable but measurement only occurred to a maximum depth of 12’ which was entirely too shallow to determine stratification patterns and oxygen dynamics throughout the water column.

Surface water total phosphorus concentrations increased from 2014 values (23.8 µg/L) to a historical maximum of 43.2 µg/L during the 2016 season. TP concentrations during the November 2016 sampling event ranged between 28.4 µg/L and 43.2 µg/L, all of which were above the recommended threshold of 24 µg/L. TP declined by the 2017 season, all well below the recommended threshold.

SRP showed a similar pattern, with moderate values in 2014 increasing to a historical maximum in November 2016 and subsequently declining in 2017.

During 2016, the lake experienced its first known blue/green algae bloom (Microcystis).

While phosphorus is often the limiting nutrient in lakes, that is, the nutrient in lowest abundance relative to biological demand, and therefore often governs algal biomass and chlorophyll a production, it is often useful to evaluate nitrogen as well as the ratio between these two elements which may dictate not only the abundance of algae but also the type of algae growing in the lake.

While the historical dataset is relatively limited, both in terms of standardization but also in the number and temporal location of events, there does seem to be a pattern of increasing nitrogen concentrations and increasing deviation between TN and TP with increasing phosphorus limitation occurring. As P limitation increased in the lake, as indicated by elevated nitrogen and greater disparity between N and P, small increases in P loading may have resulted in significant increases in algal biomass. In regards to the 2016 bloom, this P loading could have occurred during the month of September 2016 which showed a +4.27” increase over normal precipitation with a total monthly accumulation of 8.01”.

Internal loading in lakes is a complex process, which can occur via physical, chemical and/or biological processes and varies both spatially and temporally. Typically, internal loading in deep, dimictic lakes is governed primarily by redox reactions that occur under anoxia on iron- phosphate molecules and less upon biogenic or organic-bound P. This is typically the result of the need of higher temperatures which govern high rates of biological release of P from organic sources versus the chemical processes which govern P transmission from ferrous sources. Upon anoxia, iron-phosphate molecules become chemically reduced thereby leading to the dissolution of phosphorus from iron whereby it transfers to the hypolimnetic waters. Aluminum is another metal which binds phosphorus in the sediments but differs from iron in that the molecular bond between aluminum and phosphorus does not break under redox conditions associated with hypolimnetic anoxia. This unique property of aluminum is why lake managers often utilize aluminum-based products for mitigation of internal loading of P. Biological processes of internal loading include benthic bioturbation via benthic feeding fishes, such as common carp, or through benthic dwelling macroinvertebrates.

ACTIONS TAKEN:

ACTION #1:

A lake-wide nine location Water Quality Analysis sampling program was conducted on October 28, 2016 by SOLitude Lake Management and analytical testing was performed by SePRO Research laboratory after the sudden first known appearance of an algae bloom in the summer/fall of 2016. The testing included algae identification and cell counts, vertical profiles for temperature and dissolved oxygen down to 10 feet, and sampling of surface water for pH, dissolved oxygen, conductivity, alkalinity, hardness, turbidity, phosphorus (total and free reactive), total nitrogen and chlorophyll a, and total sediment phosphorus (top 10 cm).

CONCLUSIONS: The results indicated the dominant presence of Microcystis species (a cyanobacteria commonly referred to as blue-green algae that is a potential toxin, scum, and taste/odor producer), moderate to high amounts of total phosphorus and moderate amounts of total nitrogen which indicate the presence of developing eutrophic conditions in the lake (high nutrient levels that stress the lake). The higher than normal water temperatures and drought conditions (lack of lake flushing) during the summer of 2016 also likely contributed to the occurrence of algae blooms. The lack of vegetation in the lake has changed the biological balance of the lake in favor of phytoplankton/algae in the water column.

ACTION #2:

The first known Microcystis (potentially toxic blue-green algae) bloom occurring in the fall of 2016 served as the impetus for the commissioning of an extensive Sediment Cores/Bathymetry Study of the lake with included alum dosing recommendations. This was conducted by HAB Aquatic Solutions and Aquatic Environmental Consultants in February 2017.

This study aimed to collect sediment cores at seven (7) in-lake stations. Three (3) of these stations were characterized by water depths of ≤ 12 ft while the remaining samples were taken in water depths ≥ 32 ft. Two (2) of the cores were collected in deep water of 71 and 80 ft. The sediment cores were subsequently partitioned into 2cm sections and analyzed for various phosphorus fractions including: total phosphorus, total organic phosphorus, biogenic phosphorus, mobile phosphorus (Iron-bound plus loosely sorbed P), aluminum-bound phosphorus and calcium bound phosphorus. Furthermore, samples were analyzed for percent water, percent solids and total organic carbon. In addition, cores were analyzed for aluminum, iron and calcium. Finally, alkalinity was measured in the water column.

CONCLUSIONS: The total amount of phosphorus (P) in the sediments is high and a significant pool of P exists in the Lake Holiday sediments that are contributing to available P in the water column via internal loading. The first internal source is organic P which is at a very high concentration relative to the other fractions. Biogenic P represents the portion of organic P that is most readily available for dissolution into the water column. The biogenic P concentrations are also very high. The second internal loading source is the P that is bound to iron. Internal loading from this source generally occurs when the sediments are anoxic (no oxygen). The iron bound concentration is low. The aluminum bound fraction is very high. Various alum application strategies and dosing were recommended.

The low iron-bound P content of the deep-water sediment cores of Lake Holiday, combined with the large aluminum-bound P fraction, does not indicate the sediments would be a significant source of internal P loading except for possibly under the combination of extended drought conditions, sustained thermal stratification and deep-water anoxia. The binding of alum to organic bound P is generally low and therefore may not be an appropriate remediation measure for Lake Holiday. Additional monitoring should be conducted, with full thermal and oxygen profiles and multiple-depth P measurements, in the years to come to refine the understanding of P dynamics in Lake Holiday.

ACTION #3:

An Estimated Annual and Seasonal Streamflow and Loading of Nutrients and Sediment to Lake Holiday study was performed by Pagenkopf and Ludwig of TetraTech in February, 2017. This is a scientifically based approximation of the loading of nutrients and sediments from the surrounding watershed. In addition annual and seasonal flows in and out of Lake Holiday are provided.

CONCLUSIONS: The total watershed is 8,424 acres or 13.16 square miles. There are 14 sub- tributaries with distinct entry points into the lake. The primary land use is agricultural/rural which represents 89% of the total drainage area. The two largest tributaries are Isaacs Creek (61.5% of watershed drainage) and Yeiders Run (19%). The estimated annual loadings of total phosphorus (TP) and total nitrogen (TN) are 4,247 and 38,547 lbs per year. The estimated annual loading of sediment is 2240 to 2412 tons per year. 21% of TP loads from Yeiders and 56% from Isaacs. The approximate total mass of TP in the upper 10cm of lake bottom sediment is 141,135 lbs. It would take approximately 33 years to create a build-up of this much TP mass within the lake.

Approximately 10 inches of runoff flow over the spillway during an average year. Therefore nutrients and sediment discharged into the lake accumulate over time rather than being flushed out over the spillway.

ACTION #4:

The recognition by Lake Holiday that there was much to be learned about deep freshwater reservoirs, water quality, and how nutrient and sediment loading from the tributaries contributes to the creation of algae blooms led to hiring the environmental consultant, Princeton Hydro in 2017. They have certified limnologists and environmental engineers on staff.

Princeton Hydro performed Lake and Tributary Water Quality Analysis over the course of the 2017 growing season. The data collected throughout the year were selected to accurately assess the trophic state (algal concentrations), type of algae and phosphorus dynamics in the lake system. Furthermore, preliminary assessments of the tributaries were conducted through the monitoring of discharge, phosphorus and sediment. Storm water monitoring is still on-going due to the lack of appropriate rain events and is anticipated to be completed in Spring 2018.

The 2017 water quality monitoring program consisted of three (3) in-lake and baseflow tributary monitoring events and three (3) stormwater monitoring events. Lake water quality monitoring was conducted at six (6) in-lake and four (4) beach stations while baseflow tributary sampling was conducted at three (3) stream stations. Stormwater tributary sampling was to be conducted at a total of eight (8) stations.

Lake sampling consisted of the measurement of various in-situ¸ discrete, biological and cyanotoxin parameters. In-situ data were collected in profile from top to bottom of the water column by means of a calibrated Hach MS5 multi-probe water quality meter. In-situ data consisted of the measurement of temperature, specific conductivity, pH, and dissolved oxygen at 1.0 m increments. In addition, Secchi disk transparency was measured. In-situ and Secchi measures were conducted at each station.

Discrete water quality monitoring consisted of the analysis of chlorophyll a (Chl a), ammonia (NH3), nitrate (NO3), total phosphorus (TP), soluble reactive phosphorus (SRP) and total suspended solids (TSS).

In addition, TP and TSS monitoring were conducted at Isaacs Creek, Yeiders Run and Miller Run. All discrete chemical analysis was conducted by Environmental Compliance Monitoring of Hillsborough, NJ as this laboratory has the capability to meet the low minimum detection limits necessary for proper limnological analysis.

Princeton Hydro also collected plankton samples to assess community composition, densities and presence of the cyanotoxin microcystin. Plankton grab samples were collected at the surface and mid-depth of L1 and the surface of L6. These samples were subsequently preserved with Lugol’s solution, identified and enumerated (cells/mL). In addition, plankton tows were conducted at L1 and L6 and analyzed for zooplankton and phytoplankton community composition and relative abundance (i.e. Abundant, common, present etc.). Finally, samples were collected at each of the four (4) beaches and analyzed for community composition. These samples were also tested for the cyanotoxin microcystin through the utilization of Abraxis test kits.

Finally, stream discharge was measured at each of the three baseflow stations during standard monitoring. Prior to measuring discharge, a staff gage was installed at stations I-1 and M-3. These durable, metal gages were installed on cast iron piping with u-bolts and hammered into the streambed until the point of refusal. Discharge measurements were made utilizing a Price AA current meter according to methods established in USGS Discharge Measurements at Gaging Stations – Techniques and Methods 3-A8 (USGS, 2010).

CONCLUSIONS: Lake Holiday exhibited thermal stratification throughout the 2017 growing season. Dissolved oxygen varied throughout the waterbody with ample oxygen at the surface declining to conditions under recommended habitat thresholds. Anoxic conditions in the hypolimnion were present but were sporadic in the deeper waters during each event. Phosphorus concentrations were low and, despite periodic anoxia, did not increase in the deeper waters which is what would be observed under large-scale internal loading of this nutrient. Clarity was acceptable throughout the monitoring period as a result of overall low algal densities as indicated by acceptable chlorophyll a concentrations. The algal community was comprised largely of smaller celled cyanobacteria and colonial green algae which did not result in nuisance conditions.

The historical analysis showed water quality in 2017 to be markedly improved compared to conditions measured in October 2016. The sediment core data, while indicating an ample P pool in the sediments, do not indicate the probability of large-scale internal P loading except, possibly, under conditions of extended drought and hot, dry weather. Furthermore, the amount of P in the sediments is highly partitioned as biogenic or organic P which typically does not bind to standard alum. As such, any possible treatment in the future, if conducted, should be assessed with an alum surrogate or alternative nutrient inactivation product.

Finally, based on the available data to date, the relative contribution of internal phosphorus loading in Lake Holiday on an annual basis may be extremely variable and highly dependent on local weather conditions. Thus, while conditions in the late summer and fall of 2016 may have been conducive for high rates of internal phosphorus loading, similar conditions were not apparent in late summer / fall of 2017. This is reflected by the optimal water quality conditions experienced in 2017 and extremely low deep-water phosphorus concentrations. Additionally, the elevated TP concentration in late fall 2016 (< 30 ug/L) may indicate that watershed-based, external loading may have been the driving force triggering that year’s blue-green algal bloom.

Further data collection, similar to that conducted in 2017, is absolutely critical in documenting any shifts in water quality and gauging lake response to varying climatic variables.

FUTURE REQUIRED ACTIONS:

ACTION #1:

Conduct weekly e.coli testing throughout the recreational season, May-September. Samples should be taken at a minimum of 5-7 stations. The following should be included each week; Beach 1, Beach 2, Mid lake marina, Yielder’s Run cove and Isaac’s Creek cove. The upper tributary of Yielder’s @ the Lakeview Bridge and Isaac’s at the Whitacre Bridge should be periodically tested to ensure the water flowing into the lake is within the EPA guidelines.

Volunteers taking the weekly samples will be trained by the Friends of the Shenandoah. The samples will be taken to the FOS lab at Shenandoah University where they will be analyzed. If any of the areas exceed the EPA standard of 235 e.coli CFU/100 ml, then the community is notified and a retest is taken as soon as possible, or when weather conditions permit. Depending on the area or areas that exceed the EPA limit, certain areas or the entire lake may be posted as no swimming.

ACTION #2:

Conduct water quality monitoring at the established six (6) In-lake stations three times (3) during the growing season (May, July and September). The goal of such additional monitoring in 2018 is to determine if the conditions observed in 2017 (i.e. only periodic anoxia and extremely low phosphorus conditions immediately over the sediments) are common or rare. Such additional data will aid in quantifying the relative cost effectiveness of nutrient inactivation with either alum or a surrogate product.

In-situ: At each station collect in-situ measures of temperature, specific conductance, dissolved oxygen and pH at 1 meter intervals throughout the water column. Monitor transparency with Secchi disk.

Discrete laboratory analysis: Ensure certified laboratory run samples with minimum detection limits sufficient for limnological analysis. • L1: Surface – Chlorophyll a (Chl a), Ammonia (NH3), Nitrate (NO3), Soluble Reactive Phosphorus (SRP), Total Dissolved Phosphorus (TDP), Total Phosphorus (TP), Total Suspended Solids (TSS); Mid – Chl a, NH3, NO3, TP; Deep – NH3, NO3, SRP, TDP, TP

• L2: Surface – Chl a, SRP, TDP, TP, TSS; Deep – SRP, TDP, TP

• L3: Surface – Chl a, SRP, TDP, TP, TSS; Deep – SRP, TDP, TP

• L4: Surface – Chl a, SRP, TDP, TP, TSS; Deep – SRP, TDP, TP

• L5: Surface – Chl a, SRP, TDP, TP, TSS; Deep – SRP, TDP, TP

• L6: Surface – Chl a, NH3, NO3, SRP, TDP, TP, TSS; Deep – SRP, TDP, TP

Plankton/cyanotoxins:

• L1: Tow for semi-quantitative analysis of phyto and zooplankton; Surface grab for phytoplankton enumeration (cells/mL); Mid grab for phytoplankton enumeration (cells/mL)

• L6: Tow for semi-quantitative analysis of phyto and zooplankton; Surface grab for phyto enumeration (cells/mL)

• Beaches 1, 2P, 2D and #: Semi-quantitative phytoplankton; Test for microcystin utilizing ELISA based methodology

Tributary monitoring: Conduct baseflow measurements at the three tributary stations (I1, M1 and M2) during three (3) events coinciding with lake monitoring.

In-situ: Measure temperature, specific conductance, dissolved oxygen and pH

Discrete: – Lab analysis for TP and TSS

Discharge: Measure stream discharge utilizing USGS methodology

General requirements: The aquatic/environmental company conducting testing should have, at a minimum, one certified lake manager (CLM) on staff with preference for limnologist with doctoral degree. In addition, staff should include one professional engineer registered in the state of Virginia.

WATER QUALITY PARAMETERS:

Temperature

A lake’s water temperature is often a primary factor controlling many biological and chemical reactions. Primarily dependent upon solar radiation and secondarily by ambient air temperatures, thermal diffusion is generally aided through wind driven or artificial mixing. Changes in water temperature with depth are primarily dependent upon the degree of light attenuation, water clarity, lake depth, and the topography and vegetative cover surrounding a lake.

The morphology of the lake basin is the primary factor determining temperature distributions throughout the water column. Essentially, shallow basins experience much less spatial variation in temperature distribution throughout the water column than are experienced in deeper basins. An important characteristic of changes in water temperature are the resultant changes in water density. Many deeper lakes (>8’ max depth) within the North American temperate zone experience strong variation in temperature throughout the water column due to seasonality.

Lake Holiday, with a relatively deep maximum depth, is generally characterized as a dimictic lake. That is, this lake experiences direct stratification during the summer, inverse stratification during the winter, and complete circulation during a limited timeframe during the spring and autumn.

Summer thermal stratification results when increasing solar radiation and air temperatures, in conjunction with a few days of little wind activity, combine to thermally stratify the water column. Thermal stratification consists of a relatively warm upper water layer, termed the epilimnion, a transition zone, termed the metalimnion or thermocline, and a cold, deep water layer, termed the hypolimnion. The density differences imparted through thermal stratification serve to inhibit wind driven mixing of the water column thereby effectively sealing off the hypolimnetic layer from contact with the atmosphere. This phenomenon has important implications in that bottom waters of thermally stratified systems may become devoid of oxygen due to excessive bacterial decomposition of organic matter and a lack of atmospheric replenishment of dissolved oxygen through diffusion. Resultant conditions of hypolimnetic anoxia include internal sediment release of metals and phosphorus, and reduced fish habitat.

In the late summer and fall, declining air temperatures result in a negative heat income to the lake, and a loss of heat exceeds inputs from solar radiation. Surface waters are thus cooled and induce convection currents which serve to erode the metalimnion of the lake until the water column exhibits a uniform temperature and therefore uniform density. At this point the lake experiences fall turnover. The transition from the final stages of weak summer thermal stratification to fall turnover are often times abrupt, and can occur over a period of a few hours, especially if associated with the high wind velocities of a storm (Wetzel, 1975).

Another important impact of temperature is its effect on the solubility of gases. Simply, colder water may hold more dissolved gases, such as oxygen, than warmer water. This phenomenon has important implications in lakes as rates of algal productivity and algal and animal respiration increase during the late summer months when water temperatures are warmest. While algal and plant photosynthesis produces oxygen as a byproduct during the daylight hours, these organisms actively respire during the night thereby consuming dissolved oxygen to metabolize those carbohydrates produced through photosynthesis. As such, increasing algal densities in concert with warm water temperatures may combine to exhaust all available dissolved oxygen thereby leading to fish mortality. While it is important to recognize the linkages between temperature and dissolved oxygen solubility, such extreme conditions which lead to fish mortality are generally only a concern in hypereutrophic waterbodies and are likely to not occur within Lake Holiday.

Dissolved Oxygen

Dissolved oxygen is crucial to almost all biochemical reactions occurring in freshwater ecosystems. Primary sources of dissolved oxygen are diffusion from the atmosphere and photosynthesis, while sinks are biological respiration and bacterial decomposition of organic matter. The abundance and distribution of dissolved oxygen in a lake system is based on relative rates of producers (photosynthetic organisms) versus consumers (metabolic respiration). Again, as noted above, it is also frequently influenced by the thermal properties of the water column. This affects dissolved oxygen levels not only as a result of stratification, but also in terms of the extent of dissolved oxygen saturation. Simply put, warmer water has less dissolved oxygen retention capacity than does cooler water. As such, the concentration of dissolved oxygen in cooler water is typically greater than warmer water.

As plants (including aquatic macrophytes and single-celled phytoplankton) photosynthesize they take up water and carbon dioxide and through the use of light energy convert those reactants into oxygen and glucose. This serves to increase the net concentration of dissolved oxygen in lakes during the day in the uppermost water layers where there is ample sunlight to support photosynthesis; termed the photic zone. As such, dissolved oxygen concentrations are generally higher in the upper water layers and lower in the lower water layers due to a lack of photosynthetic activity in conjunction with aquatic animal/bacterial respiration.

As emphasized above, relative concentrations of dissolved oxygen are also due to temperature and density differences throughout the water column. When lakes thermally stratify there is generally a correlated stratification of dissolved oxygen levels. Lower water layers usually contain less dissolved oxygen as they cannot mix with upper water layers whereby dissolved oxygen concentrations would be replenished with atmospheric sources. In highly productive lakes the hypolimnion may become devoid of oxygen due to bacterial decomposition of excessive inputs of organic material. The source of this material may either be from excessive phytoplankton production in the upper water layers that then sink to the bottom when they die (autochthonous) or from excessive watershed derived sediment loading (allochthonous) or more likely a mixture of the two as they are inherently intertwined. Also, as dissolved oxygen concentrations are generally measured during the daytime, when concentrations are highest, there will be far lower concentrations at night when photosynthesis ceases and diffusion is the sole input of oxygen to the lake.

An important consequence of anoxic conditions in the hypolimnion includes both reduced fish habitat and release of metals and phosphorus, a process termed internal loading. Internal loading occurs when tightly bound iron and phosphate sediment complexes are chemically reduced thereby dissociating phosphorus from iron and making it available for diffusion into the water column. This process has been documented to contribute to the overall eutrophication of many lakes as this internal source of phosphorus is pulsed into the photic zone during strong storm events whereby it may serve as fuel for excessive algal growth. This source of phosphorus is also utilized by certain types of cyanobacteria that can vertically migrate throughout the water column to uptake phosphorus in deep waters and then migrate to the photic zone to initiate photosynthesis.

Guideline: >1.0 mg/L is needed to preclude internal nutrient and metal release while concentrations of 5.0 mg/L and greater should be kept in order to sustain proper fisheries habitat.

Specific Conductance

Specific conductance is defined as the ability of water to conduct an electrical current. Increases in specific conductance are due to an increase in ionic constituents from watershed soils and biological reactions and are temperature dependent. Specific conductance is normalized for the effects of temperature on conductivity values.

Watershed geology, pH, and the dissolved solids loads in runoff play an important part in determining conductance values for a particular lake. Some rocks and soils release ions very easily when water flows over them; for example, if water of low pH flows over calcareous rocks then ions of calcium (Ca2+) and carbonate (CO32-) ions will dissolve in water and raise the conductance values. Some rocks such as quartz are very resistant to weathering and in a predominately quartz geology conductance values would be low.

Two other important sources of ionic constituents in suburban watersheds are salts from road de-icing and salts derived from fertilizer runoff. As such, increases in specific conductance are often used as proxy measures of increased pollutant loading from the surrounding watershed.

Guideline: Specific conductance: <50 µS/cm low, 50 to 1,500 µS/cm typical of normal freshwaters, > 1,500 µS/cm may be stressful to aquatic organisms.

pH pH is a unit-less measurement of the hydrogen ion concentration in water. Expressed on a negative logarithmic scale from 0 to 14, every change of 1 pH unit represents a 10-fold increase or decrease in hydrogen ion concentration. The pH of pure water is 7 and is termed neutral. Any value less than 7 is termed acidic, while any value greater than 7 is termed basic.

Baseline pH values are primarily determined by the ionic constituency of surrounding geology. Watersheds draining soils of easily erodable anionic constituents are generally well buffered and as such have runoff waters with basic pH values (pH above 7). Those watersheds draining lowland soils, such as those of the coastal plains province, generally produce weakly buffered runoff and are therefore characterized by acidic surface waters (pH less than 7).

Spatial variations in pH throughout the water column are largely due to relative rates of production versus respiration. As plants and algae photosynthesize they release anions while collectively taking up acidic compounds related to carbon dioxide species. This serves to produce a net increase in pH. Conversely, respiration releases carbon dioxide which serves to drive down pH values. Given these relationships, pH values may differ substantially between the top and bottom water layers in lakes with a large amount of productivity or respiration activities.

Given the underlying geology of Lake Holiday baseline pH values would be expected to be neutral to slightly alkaline (pH 7.0 – 8.0).

Guideline: Recommended pH values are between 6 and 9. Values below 6 would be overly acidic while those over 9 would be considered overly basic. Elevated values (i.e. >8.5 are generally indicative of a strong photosynthetic input).

Transparency

Transparency in lakes is generally determined through the use of a Secchi disk. The Secchi disk is a contrasting white and black disk that is lowered into the lake until no longer visible then retrieved until visible again. The average of those two lengths is termed the Secchi depth. This depth may be influenced by algal density, suspended inorganic particles, organic acid staining of the water or more commonly a combination of all three. This parameter is often times used to calculate the trophic status (productivity) of a lake and as such is a critical tool in lake evaluation.

Guideline: >8 – 4 m (> 26 – 13 ft.) oligotrophic (low productivity), 4 – 2 m (13 – 7 ft.) mesotrophic (medium productivity), 2 – 0.5 m (7 – 2 ft.) eutrophic (high productivity), 0.5 - <0.25 m (2 – 0.1 ft.) hypereutrophic (very high productivity)

Ammonia (NH3-N)

In lakes ammonia is naturally produced and broken down by bacterial processes while also serving as an important nutrient in plant growth. In a process termed ammonification, bacteria break down organically bound nitrogen to form NH4+. In aerobic systems bacteria then break down excess ammonia in a process termed nitrification to nitrate (NO3-). These processes provide fuel for bacteria and are generally kept in balance as to prevent accumulation of any one nitrogen compound.

Ammonia is generally present in low concentrations in oxygenated epilimnetic layers of lakes due to the rapid conversion of the ammonium ion to nitrate. In addition, most plants and algae prefer the reduced ammonium ion to the oxidized nitrate ion for growth and therefore further contribute to reduced concentrations of ammonia in the upper water layer. In the anoxic hypolimnion of lakes ammonia tends to accumulate due to increased bacterial decomposition of organic material and lack of oxygen which would otherwise serve to oxidize this molecule to nitrate.

Increased surface water concentrations of ammonia may be indicative of excessive non-point source pollution from the associated watershed. The ammonium ion, unlike that of nitrate, may easily bind to soil particles whereby it may be transported to the lake during storm events. Another likely source of excessive ammonia in suburban watersheds is runoff from lawn fertilizer which is often highly rich in nitrogenous species. Increases in ammonia concentrations in the hypolimnion of lakes are generally associated with thermal stratification and subsequent dissolved oxygen depletion. Once stratification breaks down a pulse of ammonia rich water may be mixed throughout the entire water column whereby it will cause undue stress to aquatic organisms.

Guideline: Toxicity of ammonia to aquatic species generally increases with decreasing pH and increasing temperatures. The general guideline issued by the EPA is that ammonia should not exceed a range of 0.02 mg/L to 2.0 mg/L, dependent upon water temperature and pH, to preclude toxicity to aquatic organisms.

Nitrate (NO3-N)

Nitrate is the most abundant form of inorganic nitrogen in freshwater ecosystems. Common sources of nitrate in freshwater ecosystems are derived from bacterial facilitated oxidation of ammonia and through groundwater inputs. The molecular structure of nitrate lends it poor ability to bind to soil particles but excellent mobility in groundwater.

Nitrate is often utilized by algae, although to a lesser extent than ammonia, for growth. Nitrate distribution is highly dependent on algal abundance and the spatial distribution of dissolved oxygen concentrations. In many eutrophic lake systems nitrate concentrations show temporal and spatial variability due to algal productivity and relative concentrations of dissolved oxygen.

Guideline: Nitrate concentrations < 1.0 mg/L typical of healthy freshwaters. Values > 1mg/L may be indicative of high nitrogen pollution while values > 10 mg/L exceed drinking water criteria.

Total Phosphorus (TP)

In lake ecosystems phosphorus is often the limiting nutrient, one whose abundance is lowest relative to demand. As a result, phosphorus is often the primary nutrient driving excessive plant and algal growth. Given this nutrient limitation only relatively small increases in phosphorus concentration can fuel algal blooms and excessive macrophyte production. By monitoring total phosphorus concentrations, the current trophic status of the lake can be determined and future trends in productivity may be predicted. Furthermore, spatial variation in phosphorus may exist in waterbodies which experience internal sediment release of this nutrient under anoxic conditions.

Guideline: Concentrations < 12 µg/L oligotrophic, 12 – 24 µg/L mesotrophic, 24 – 96 µg/L eutrophic, > 96 µg/L hypereutrophic

Soluble Reactive Phosphorus (SRP)

Soluble reactive phosphorus represents the dissolved, inorganic portion of total phosphorus metrics. This species of phosphorus is readily available for assimilation by all algal forms for growth and is therefore normally present in limited concentrations except in very eutrophic lakes or during periods of acute phosphorus loading.

Guideline: < 5 µg/L low, 5 – 10 µg/L moderate, > 10 µg/L high

Total Suspended Solids (TSS)

The concentration of suspended particles in a waterbody that will cause turbid or “muddy” conditions, total suspended solids is often a useful indicator of sediment erosion and stormwater inputs into a waterbody. Because suspended solids within the water column reduce light penetration through reflectance and absorbance of light waves and particles, suspended solids tend to reduce the active photic zone of a lake while contributing a “muddy” appearance at values over 25 mg/L. Total suspended solids measures include suspended inorganic sediment, algal particles, and zooplankton particles.

In addition, as phosphorus molecules are often times tightly bound to soil particles, elevated total suspend solids measures may serve as indicators of not only excessive sediment inputs but also excessive phosphorus inputs to a waterbody.

Guideline: < 10 mg/L for lakes (low), 10 – 25 mg/L (moderate), > 25 mg/L (high

Chlorophyll a (CHL A)

Chlorophyll a is the primary photosynthetic component of all algae and as such is often used as a proxy indicator of total algal biomass. Increases in chlorophyll a concentration are generally attributable to increases in total algal biomass and are highly correlated with increasing nutrient concentrations. As such, elevated chlorophyll a concentrations are a visible indicator of increased nutrient loading within a waterbody.

Guideline: 0 – 2.6 µg/L oligotrophic, 2.6 – 20 µg/L mesotrophic, 20 – 56 µg/L eutrophic, > 56 µg/L hypereutrophic

Phytoplankton

Phytoplankton are the base of the trophic web in any lake system and largely determine the quality of the waterbody from ecological, recreational, and aesthetic perspectives. Phytoplankton are described herein as single celled and colonial algae, forming surface and benthic (bottom) colonies that act as primary producers through photosynthesis within the lake. Phytoplankton growth is largely a function of nutrient concentrations, specifically phosphorus and nitrogen as discussed above, and available light intensity. Excessive nutrient levels can cause undesirable phytoplankton blooms that negatively impact water clarity and may form dense, floating surface mats. In addition to limiting phytoplankton biomass, nutrient levels can directly affect the phytoplankton assemblage, most notably low N:P (nitrogen to phosphorous) environments favor the growth of the undesirable Cyanobacteria division (blue-green algae). These are the algae that commonly form surface scums that are not only aesthetically unpleasant but typically produce strong, noxious odors.

Guidance: Cell densities > 15,000 cells/mL may be indicative of a bloom of that genus.

Zooplankton

Zooplankters are the micro-animals that inhabit the water column of an aquatic ecosystem. The zooplankton of freshwater ecosystems is represented primarily by four major groups: the protozoa, the rotifers, and two (2) subclasses of Crustacea, the cladocerans and the copepods. The cladocerans are a particularly important taxon within an aquatic ecosystem, and factor importantly in lake management. Cladocerans are typically characterized as large, highly herbivorous zooplankters capable of keeping algal densities naturally in check through grazing pressure. Many species of copepods are herbivorous and can also help maintain algal densities.

Aside from algae, many copepods also feed on other small aquatic animals and debris. Rotifers display a diversity of feeding habits. A portion of omnivorous rotifers feed on any organic material including bacteria and algae, while predaceous rotifers feed primarily on algae and other rotifer species. Protozoa feed either through ingestion or photosynthesis.

Guidance: Zooplankton densities of >1,000 organisms/mL may be indicative of a bloom of that genus.

Microcystin

Microcystins are a class of toxins produced from cyanobacteria of the Microcystis, Planktothrix, Anabaena, Oscillatoria and Nostoc genera. Microcystins are primarily hepatotoxins but may also produce skin rashes, breathing problems and digestive issues. These toxins are produced primarily during large-scale cyanobacteria blooms in warm, stagnant water. In Lake Holiday, these blooms and associated toxins are primarily a concern at the bathing beaches and anywhere pets may enter and drink the water.

Guideline: USEPA has established a threshold concentration for microcystin of 4 µg/L for recreational waterbodies.

FUTURE PROPOSED ACTIONS:

ACTION #1:

Maintain health and safety of water for swimming, pets and recreational activities by continued annual collection of e. coli data and community notification when bacterial levels are high.

ACTION #2:

Work with Aqua, VA DEQ and the community to identify and prevent lift station and grinder pump overflow. ACTION #3:

Consider a long term objective of reaching out to land owners outside of Lake Holiday to educate and work with them to minimize nutrient and sediment overload into Lake Holiday.

ACTION #4:

Implement watershed/tributary/lake best management practices to curb nutrient and sediment flow into the lake.

ACTION #5:

Continue annual collection of water quality data within lake and tributaries to quantify and qualify trends in the overall health of the lake.

SHORELINE EROSION:

PROBLEM:

Heavy wake action coupled with the fragile nature of our shale/soil composition and the steep shoreline has led to excessive shoreline erosion in certain areas.

BACKGROUND:

The program for sediment/erosion control involves inspecting the shoreline for damage, evaluating the performance of existing erosion control devices, evaluating the sedimentation and its impact on erosion, investigating the impact of nuisance animals such as beavers, denuded vegetation and fallen trees and well as the health of trees where the soil is being eroded away.

Lake management firms will do shoreline surveys and provide reports, maps, and pictures delineating the damage and recommending repairs and solutions to problems. Engineering firms must design the appropriate specifications for shoreline renovation and recommend particular erosion control measures. Appropriate permits must be obtained before a project is undertaken.

Natural shoreline construction is one way to protect the shoreline and provide a natural transition between the water and upland area. Natural shoreline construction includes native plantings, natural stone, bio-logs, and other bio-engineering methods. Natural shorelines also act as buffer zones, collecting excess nutrients running off the upland area toward the water.

The shoreline and shallow water areas provide essential habitat for many fish and wildlife. Well-designed shoreline protection programs will enhance habitats. A proper shoreline will act as a buffer between land and water which ensures that unwanted nutrients, sediment and muck stay away from the water. A properly maintained and reinforced shoreline encourages plant growth and habitats for small animals which improves the ecosystem of the land and the water.

ACTIONS TAKEN:

ACTION #1:

Maintenance should inspect the shoreline for erosion damage, evaluate the performance of existing erosion control, and investigate the impact of beavers and fallen trees and the health of trees where the soil is being eroded away on an annual basis. Erosion control measures for all populated coves are being implemented as part of road maintenance.

ACTION #2:

Enforce the boating regulations regarding “no wake” zones as well as staying at least 100 ft. from the shoreline in the high-speed areas

PROPOSED ACTIONS:

ACTION #1:

Investigate possible options such as floating wave dampening systems in certain high-speed zones where shoreline erosion is significant

WATERSHED MANAGEMENT/SEDIMENT CONTROL:

PROBLEM:

Heavy rainfall events, construction runoff, agricultural activities, and the steep slopes common to the surrounding watershed has led to excessive amounts of sediment being discharged into the coves from the watershed causing the coves to become much shallower than they naturally would be and in some instances to be unnavigable. Nitrogen and phosphorus also drain into the lake from the surrounding watershed. In particular, phosphorus tends to attach to sediments transported in streamflow. When the sediment accumulates on the lake bottom, it can lead to nutrient overloading resulting in algae blooms and impacting the fish habitat.

BACKGROUND:

The Lake Holiday watershed encompasses a total of 8,487 ac while Lake Holiday proper is approximately 249 ac, resulting in a watershed to lake ratio of 34:1. Typically, watershed to lake ratios greater than 10:1 are associated with increased loading of sediments and nutrients above that which would occur in a naturally glaciated lake system. As such, Lake Holiday is more prone to eutrophication (increased algae and plant growth).

Watershed size and the land uses, soil types, topography and geology in concert with variable climatic conditions all influence the quantity of water, its temporal distribution and the nutrient load into the lake. A direct correlation exists between watershed disturbance and increased nutrient loading. The conversion of forests to agricultural, residential, commercial and industrial lands brings about an increase in nutrient loading due to increases in erosion and a multitude of other factors. One of the primary areas of focus is understanding how the watershed transports water and nutrients to the lake and using this information, in concert with in-lake data, develop a cohesive lake management plan.

The Lake Holiday watershed is characterized by moderate to steep relief with slopes ranging up to 65%. The soils are characterized by moderately rapid to rapid permeability and medium runoff potential. Fertility and organic content are low while erosion potential is moderate.

Nitrogen and phosphorus are essential to aquatic plant growth but periodic over enrichment through excess sediment buildup and stormwater runoff can lead to excess growth of algae and aquatic plants and can alter the diversity and composition of aquatic species in the water. Erosion of soil particles from steep slopes, disturbed ground, and stream beds is the primary source of phosphorus in aquatic systems. Surface runoff containing orthophosphates from fertilizers and decaying organic matter plus animal waste may also contribute to phosphorus and nitrogen enrichment. Suspended particles also play a role in transporting phosphates throughout the water body.

Many species of cyanobacteria (blue-green algae) have the ability to fix nitrogen and have a competitive advantage over other algae in phosphorus rich environments and can become dominant over more beneficial species.

Heavy sediment loads may lead to increased turbidity caused by suspended soil particles which restrict light penetration and limit photosynthesis. Besides making the water cloudy, these particles can clog fish gills and impair respiration, smother spawning areas, negatively affect egg and larval development and reduce growth rates in fish.

Inflow to the lake is derived from groundwater and various tributaries. Isaacs Creek, which flows into Lake Holiday from the southwest, comprises 63% of the watershed area. Yeiders Run, which flows into the Lake from the north, drains approximately 19% of the total watershed. The remaining subwatershed drains 18% of the watershed and is comprised of various ephemeral and semi-perennial gullies and water courses associated with the LHCC residential neighborhood. Stormwater in the watershed is collected via roadside ditches and shunted to the lake without conventional treatment.

Overall, the watershed of Lake Holiday is like that of many lake communities in the Appalachian region of the mid-Atlantic. That is, the area is characterized by steep, rocky slopes which generally preclude stormwater treatment from conventional means such as retention basins or large vegetated areas. ACTIONS TAKEN:

ACTION #1:

Princeton Hydro conducted a Pollutant and Hydrologic Loading Analysis in 2017 computed from the Mapshed modeling effort to determine the relative contributions of watershed, internal and atmospheric loading of nutrients and sediment to the lake. LHCC had become increasingly aware of the stormwater induced impacts affecting the lake and the lake’s tributaries.

CONCLUSIONS: 85% of the hydrologic inflow in Lake Holiday is estimated to be derived from subsurface source including groundwater. The remaining 15% is estimated to occur via surface runoff during storm events. In terms of management, focus is generally placed on the “runoff” component of stream discharge as this is the water which transports sediments and nutrients to the receiving waterbody.

The annualized lake flushing rate for Lake Holiday is 1.41. The retention time, which is simply the inverse of the flushing rate, is 259 days. Due to this relatively long retention time and the fact that Lake Holiday acts more as a reservoir than a lake, most materials that enter the lake tend to stay within the lake and not get flushed out through the spillway.

This data showed watershed sources of phosphorus (external loading) to account for between 69% to 85% of the total annual phosphorus load dependent on the type and scale of internal phosphorus loading occurring in the system during any given year. This report noted that the predominance of watershed-based loading of phosphorus to the system is derived from agricultural sources which represent 50% of the watershed-based load followed by groundwater-based sources which comprise 29% of the watershed-based load. Stream bank and bed erosion were also noted to account for approximately 15% of the watershed-based phosphorus load. Residential derived phosphorus loading, associated with the LHCC community, comprises approximately 3% of the watershed-based load.

Total nitrogen loading is derived primarily by groundwater inflow which contributes 74% of the load. Nitrogen, unlike phosphorus, is readily mobilized in groundwater sources. The second greatest contributor of nitrogen to the lake is derived from the watershed with cropland being the largest contributor on a per unit area basis.

Sediments, which caused infilling of littoral areas thereby promoting habitat for plant growth, were modeled to be derived primarily by stream bank and bed erosion (62% of annual sediment load) followed by overland erosion from the watershed, primarily from agricultural sources.

Finally, refinement of the loading was conducted through sub-watershed analysis which showed Yeiders Run to contribute the highest TP, TN and sediment load, per unit area, compared to Isaacs Creek and the remaining portions of the watershed. Still, the sheer size of the Isaacs Creek watershed imparts the bulk of nutrient and sediment loading to the lake. Based on Mapshed model computations performed by Princeton Hydro, on an annual basis, 1,511,536 lbs/yr of sediment, 12,210 lbs/yr of total nitrogen and 1,264 lbs/yr of total phosphorus are transported to Lake Holiday from watershed-based sources.

Internal phosphorus loading to the lake comprises between 11% of the total load under a ‘best case’ scenario to 28% of the load under the ‘worst case’ scenario. Under the worst case scenario the phosphorus load may shift the lake towards planktonic blooms of nuisance algae such as those of the cyanobacteria. The internal phosphorus load, unlike that of the watershed load, may occur over a relatively short period of time over the growing season. This source of P may be accessible to certain cyanobacteria which can vertically migrate throughout the water column to uptake deep-water P or this P may become entrained in the thermocline during storm events. Also, the internal P load is redistributed throughout the water column in fall during thermal mixing. It will be important to monitor the lake in the future to develop a cohesive view of this loading source under varying climatic conditions.

An assessment was also performed of what amount of phosphorus may be removed if submerged aquatic vegetation (SAV) became reestablished in the littoral zones of the lake. The littoral zone was estimated to encompass approximately 31 acres which is 12% of total lake area. If the phosphorus load of 1,264 lbs per year was just apportioned to the littoral zone of 31 acres that would result in 158 lbs P/littoral zone. Considering the likely removal efficiency based on other scientific studies of 20% there would be a 2.5% reduction of the annual watershed- based TP load.

Since the phosphorus load from agricultural sources is generated on land outside the property boundaries of the LHCC community, it will be necessary (on a longer term basis) to develop partnerships with those land owners to educate them on non-point source nutrient loading and to initiate best practices to minimize loading to Isaacs Creek and Yeiders Run. Much of this management will be predicated on developing relationships with those in the watershed and local entities, such as the Lord Fairfax Soil and Water Conservation District.

With that said, nutrient loading from the LHCC community should not be ignored due to the close proximity of this source to the lake. LHCC should stress the need for watershed conservation and the role impervious areas and development plays on increasing stormwater sheet flow and the deleterious impacts this has on transporting sediment and nutrients and increasing stream bed and bank scour resultant from ‘flashy’ runoff events. Reducing impervious area, promoting green infrastructure such as rain gardens and vegetated bioswales, and educational outreach to homeowners may all go far towards promoting watershed conservation and best management.

ACTION #2:

Princeton Hydro was retained during 2017 to conduct a Hydrologic Analysis and BMP (Best Management Practices) Feasibility Study of Isaacs Creek and Yeiders Run. The purpose of the study is to determine how to reduce pollutant loading and control stormwater flows associated with the sub-watersheds. The generation of hydrologic data, including peak flow rates and total storm volumes under varying recurrence intervals, in combination with Mapshed modeling data were utilized by Princeton Hydro to inform BMP selection from a planning perspective.

The BMPs were evaluated from a water quality and stream channel erosion functional perspective. BMP selection was predicated on site specific feasibility including topographic and geologic constraints, contributing drainage area, environmental impacts, and access for creation and maintenance.

A Pollutant and Hydrologic Loading Analysis of Yeiders Run and Isaacs Creek were conducted by Princeton Hydro utilizing the WinTR-55 modeling program. This program is applicable to watersheds ranging in size from approximately 1 acre to 25 square miles which are characterized by channel or structure reaches. Princeton Hydro analyzed the effects of the 1- year, 2-year, 5-year, 10-year, 25-year, 50-year and 100-year 24-hour storm events as a component of the selection of appropriate best management practices. These events are defined as the probability of a storm of a given magnitude occurring within time frame, or “recurrence interval.” Thus a 1-year storm statistically has a 100% probability of occurring at least once in a given year, a 2-year storm a 50% probability, a 5-year storm a 20% probability, a 10-year storm a 10% probability and a 100-year storm a 1% probability. It must be emphasized that these are probabilities and thus it is “possible”, although unlikely, to have two or three 100- year events within a single year. The rainfall amounts associated with each of these events reflects the intensity or rate; that is the amount of rainfall occurring over a 24-hour period.

Ultimately, any stormwater BMP selected for these drainage areas must be able to effectively treat the first flush of runoff, or the water quality volume (WQV), to enhance water quality. The water quality volume is the first 0.5” of runoff from impervious areas of development.

The BMPs assessed are viewed through the lens of ecological restoration as compared to simple site development. Therefore, the concepts of fluvial geomorphology are integral in assessing pollutant loading mechanisms and the best way to mitigate and manage these contributions in an environmentally sensitive, sustainable fashion.

Finally, the preferred areas for any recommended BMPs that may be implemented are those that would be placed on lands owned directly by the LHCC.

CONCLUSIONS: Isaacs Creek watershed comprises approximately 5,268 acres. This catchment is considerably large and comprised of a heterogenous mixture of agriculture, forest and low- density residential land-use. Flow paths in this watershed are diverse and include numerous first-order streams in addition to Isaacs Lake, a 21-acre impoundment, located in the headwater reaches. The majority of the catchment is outside of the property owned directly by the LHCC. The only area of land owned by the LHCC, which is in proximity to Isaacs Creek proper, is parcel 18 A H (Account Number: 8037555) (gis2.co.frederick.va.us, 2018). This parcel of land comprises a total of 201.36 acres and is located at the mouth of the Creek. The shape of this lot is such that it encompasses the Creek mouth area and also an extensive amount of area on the southern shoreline of the lake. This parcel of land represents the terminus of the Isaacs Creek watershed and is comprised, currently, by forested land. Siting of this parcel is particularly unconducive to most BMPs as it is characterized by steep relief characterized by slopes of 25- 65%. Furthermore, there is currently no road access to this location with the exception of the Whitacre Road causeway.

Yeiders Run watershed comprises approximately 768 acres. This catchment is comprised of a heterogenous mixture of agriculture, forest and low-density residential land-use but the majority of the stream reach south and east of route 703 is considerably forested with ample riparian buffer and appears to be in a healthy condition in terms of morphometry and floodplain connection. Areas upstream of route 703 show poor riparian corridor conditions associated with agricultural land use and are in need of restoration in terms of restoring riparian area and, possibly, floodplain connectivity. The impaired conditions upstream, in conjunction with the dominant upstream land use of agriculture, are strong points of concern relative to erosion and sediment and nutrient transport to Lake Holiday. The majority of the catchment is outside of the property owned directly by the LHCC. Two parcels of land are owned by the LHCC that are in proximity to Yeiders Run proper. Parcel 18 A I (Account Number: 8037556) includes a total of 25.30 acres and comprises, for the most part, Millers Run (gis2.co.frederick.va.us, 2018). This parcel of land then crosses back and covers the confluence area of Millers Run and Yeiders Run near the Lakeview Drive causeway where the parcel terminates. The second parcel (18 A 19 B, Account Number: 8041765) basically continues along the Yeiders Run reach, picking up where the previous parcel left off, and comprises the entirety of the lake surface area. The relief of the majority of this parcel is steep (25 – 65%) and generally confined without much real estate for conventional BMPs along the flow path.

The BMPs initially considered for both Isaacs Creek and Yeiders Run include:

Large Sediment Forebay Small Sediment Forebay Flow

Constructed Wetlands Emergent Wetland Creation

Retention Basins Flow Attenuating Structures

Infiltration Basins Floating Wetland Islands

Phosphorus Binding Blocks Submerged Aquatic Vegetation Exclusion Zone Experiments

The BMPs for Isaacs Creek and Yeiders Run above were evaluated in terms of feasibility based on several important metrics listed below:

• Would the BMP be located on property owned by the LHCC? • How much of the first flush would be addressed under the 2-Yr, 5-Yr and 10-Yr storm events? • Broad estimate of pollutant reduction capacity • Cost • Permitting complexity • Maintenance activities

The results of this feasibility matrix are provided in tables 4.1 and 4.2.

Due to lack of suitable land area, localized steep slopes, and high costs, several BMPs were eliminated from further consideration for both Isaacs Creek and Yeiders Run and include Large Sediment Forebays, Constructed Wetlands, Retention Basins, and Infiltration Basins. Princeton Hydro also evaluated various types of “phosphorus absorption” systems such as binding blocks and “socks” for possible use in Isaacs Creek and Yeiders Run. Due to the very high storm peak flow rates and water velocities calculated it was determined that these devices would not be effective or work as designed.

Princeton Hydro evaluated an alternative approach to treat a portion of the incoming water, sediments and nutrients for both Isaacs Creek and Yeiders Run. This approach involves establishing a “treatment train” of a small, constructed sediment forebay and/or large hard structure (i.e. boulders) to mitigate extreme stream flow velocities followed by emergent wetland vegetation, such as cattail (Typha latifolia), to further precipitate solids and assimilate nutrients. The third and final portion of this treatment train could include the installation of floating wetland islands which would polish incoming water and serve to further assimilate phosphorus.

PROPOSED FUTURE ACTIONS:

ACTION #1:

Refine data in tributaries for engineering and designing BMPs:

The specific location, sizing, cost analysis, and final design feasibility for such a system requires additional data to be collected in the near vicinity of where Isaacs Creek and Yeiders Run enter Lake Holiday, including more detailed local bathymetry, stream channel physical geometry surveys, and sampling of sediment types and depths to determine suitability for aquatic plant survival. This analysis is the subject of a future contract to be let by LHCC to a contractor for work to be performed during the Fall/Winter of 2018/2019.

ACTION #2:

Submerged Aquatic Vegetation (SAV) Establishment:

An in-lake restoration measure evaluated by Princeton Hydro, applicable to the lake and watershed as a whole, is the re-establishment of SAV. Lake Holiday previously contained various species of macrophytes but was dominated by the nuisance, highly invasive hydrilla (Hydrilla verticillata). As a result, the lake was stocked with triploid grass carp (Ctenopharyngodon Idella) which resulted in the removal of all SAV. SAV is critical for sediment and nutrient attenuation in littoral areas and provides habitat for the lakes biota. As such, re- establishment of native SAV has been recommended. In order to begin this process, Princeton Hydro has proposed a grass carp exclusion experiment for 2018 which looks to establish a barrier in one or more shallow areas of the lake to assess what plants return. Depending on the success of this experiment, SAV may re-establish on its own following the natural mortality of the carp (Typical life-span approximately 10-15 years). To expedite this process, the LHCC may wish to intentionally plant submerged vegetation, starting at the inlet areas of the Isaacs Creek and Yeiders Run tributaries.

The bathymetric data recommended for both inlet areas mentioned above will be critical in informing the areas in which SAV may be established. This data would be utilized in concert with Secchi disc transparency data, to determine the photic zone, that is, the zone of the lake where light penetrates to the sediments. These zones would then be targeted for SAV re- establishment. A low-cost option would be to simply see what plants return as the carp die-off. This approach should include periodic macrophyte surveys (once or twice a growing season) to document any growth and the species which plants return to the lake. A costlier approach would be to physically re-establish plants through hand planting. This analysis is the subject of a future contract to be let by LHCC to a contractor for work to be performed during the growing season of 2018/2019.

ACTION #3:

Decide on most cost-effective sediment and phosphorus control measures (BMPs). Determine location for erosion and phosphorus control measures.

ACTION #4:

Ascertain costs/funding sources and hire engineering firm to design appropriate erosion control/sediment and phosphorus mitigation measures (BMPs) for Yeiders Run.

ACTION #5:

Ascertain costs/funding sources for implementing design and construction of BMPs at Yeiders Run. Acquire necessary environmental permits and engage contractor to install sediment and phosphorus mitigation design.

ACTION #6:

Begin same investigative and implementation process for Isaacs Creek and other sites of high potential sediment and phosphorus runoff.

SEDIMENT REMEDIATION:

PROBLEM:

Runoff into the lake has caused extensive sediment to build up in the coves of the lake. There has never been removal of sediment from the lake bed therefore causing accumulation since the lake was created.

BACKGROUND:

To obtain a detailed and reliable quote estimate for dredging it is necessary to contact a dredging company such as Lake Services of Stafford, VA to come to the site and do preliminary evaluations of the dredge locations relative to the landing location, as well as the haul distance to the disposal site of the dredge spoils, and the overall dredge volume removed. There are also mobilization, installation of the disposal site, and design and permitting costs. In 2013, the Aquatic Vegetation Assessment and Sediment Management Report by Williamsburg Environmental Group (WEG) indicated there are 32,654 cubic yards of material to be removed from the lake. If you subtract the non-populated coves, you have a revised total of 10,005 CY to be removed. WEG estimated the removal costs to be $47.80/ CY, which puts the total estimated cost of dredging the 5 inhabited coves to be approximately $500,000.

The WEG study indicated that in 2013 based on project information, the appropriate permit mechanisms for lake dredging are the Nationwide 43 or the 13-RP-02, both issued by the COE and certified by DEQ for 401 State Water Quality compliance. Therefore, no additional authorizations from DEQ would be required provided all requirements of 401 certification are met. Both of these permits can generally be issued within 90-120 days of application submittal with no permit fees.

Nationwide Permit 43 authorizes maintenance dredging of existing stormwater management facilities. Use of this permit for dredging within lakes may require the applicant provide construction design or as built plans for a man-made lake. The cost of the permit is $5000- $7000.

Regional Permit 13-RP-02 authorizes dredging in non-tidal, non-navigable waters provided the dredge volume does not exceed 5,000 CY nor can the combined area of fill and excavation exceed a surface area of two acres. A post-dredge hydrographic survey completed by a state- certified engineer is required to be provided to the Corps within thirty days of the completion of dredging. The cost of this permit is $5000 - $7000.

All permits will require a wetland delineation, threatened and endangered species review, and a cultural resources review.

The WEG report identified the best option for disposal of dredge material which was Lot 21 (lots at front of development), composed of five lots owned by LHCC. Sediment needs to be tested for priority pollutants for compliance with EPA soil screening levels for residential disposal. There will be an issue with the smell of the drying sediment. In-lake disposal of sediment is another option that WEG reported on. The creation of wetland shelves or benches would increase habitat and bio-diversity. The creation of submerged forebays at strategic locations can help reduce the sediment input into the lake and will allow for periodic sediment removal under a maintenance plan. Forebay berms are usually installed in coves where the largest tributaries without upstream controls enter the lake. On our lake those coves would be where Yeider's Run and Isaac’s Creek enter the lake. Disposal of spoils in a deep part of the lake is also possible to save on spoil disposal costs. A bathymetry study would be helpful to determine places to deposit spoils within the lake.

PROPOSED FUTURE ACTIONS:

ACTION #1:

Contact mechanical dredging operators (Lake Services, Inc. of Stafford, VA most commonly used contractor in VA) for site visit, proposal, and cost estimate. Determine estimated sediment amount in cubic yards to be dredged utilizing WEG report and WSSI report sediment amounts. ACTION #2:

Gain complete understanding of steps involved including equipment required, staging area and operating area requirements (boat ramp), spoils disposal site and dewatering process, maintenance required.

ACTION #3:

Determine a measurement for when and if necessary/reasonable to perform remediation process. Ascertain method of funding project, feasibility of expense. If association decides to remediate and funds available, then create timeline for performance of project.

ACTION #4:

When necessary/reasonable to remediate, hire contractor and obtain necessary permits through contractor: COE Clean Water Act Section 404/401 Permit (may not be required), DEQ Virginia Water Protection General Permit for less than 5,000 CY ($4500, 45 day process), Frederick County grading permit including erosion and sediment control plans. (These are WSSI permit recommendations.)

CONCLUSION

This plan will continuously evolve as more data is collected and more conclusions are reached. It includes components that have already been approved by the Board to be initiated in the 2017 budget and the 2017 replacement reserve fund. This plan describes the processes and results of LHCC choosing reasonable and not cost prohibitive solutions for preserving and maintaining our most beautiful and precious resource.

LHCC has learned that our lake is a reflection of our watershed. Our watershed is very large and most of it is not on our property. Our lake is constantly evolving as it ages. LHCC has learned that the lake acts like a reservoir and very little of what enters the lake is ever flushed out of the lake. Nutrients enter the lake with sediment and serve as food for the growth of algae. There are many sources of sediment and nutrients including agricultural sources outside of our control and stream bank erosion during storm events that we can have some control over. There are algae that can cause toxic effects to pets and people such as skin rashes, stomach upset and neurological problems. We cannot ignore the lake. It requires study, analysis, repair and maintenance. The members of the community are not equipped to handle all this without the help of experts in lake management. We are beginning the process of utilizing expert help and implementing their recommendations.