Contributed by Pete Humphrey and Steve Unger
Aquatic PlantsIt is easy to take our pond’s purity and beauty for granted and not appreciate what it takes to keep it that way! It is important to understand what plants are in the lake and what that means. Some are normal and healthy, while others are invasive and undesirable. In order to keep our lake special, we may need to make changes in the way we live and do things along the shores. Our property values and our ability to continue using and enjoying the lake as we have done for many years depends on the lake’s ecology, including the presence or absence of various aquatic plants.
Just because a plant is growing in the lake doesn’t mean it is a problem! Vegetation is normal, healthy—plants release oxygen, are part of the food chain, and provide habitat for aquatic life. Some amount of aquatic vegetation is considered beneficial. But it’s important to understand the existing plant communities when changes might be occurring. To understand changes in our aquatic plant communities, we need to understand their composition, locations and size – identify changes as they develop – and be able to address issues as they emerge.
What Is The Impact On West Hill Pond?Based on recent surveys from the CT Agricultural Experiment Station (CAES) Scientists and our Limnological Consultant – both credible sources – we don’t appear to currently have any invasive aquatic plants. But it’s imperative we remain vigilant to prevent any of the many invasive aquatic plants found in lakes nearby and far, from establishing themselves in our lake. Our aquatic plants are proliferating and we need to protect the lake. In the past we have implemented several steps to mitigate issues as they arose: purchasing benthic mats, ordering run-off studies and implementing the volunteer program at the boat ramp. We are continuing to explore additional measures that we plan to review with experts before initiating.
What Can I Do to Help?A tax exempt non-profit organization has been created to pursue fund-raising and grant applications, and to address the costs of these expensive activities. Ongoing education, monitoring, monetary support and pursuit of grants are crucial! While we don’t appear to have any invasive aquatic plants now, it is imperative that we all support the following measures to prevent the introduction and propagation of potential invasive and new non-invasive pond species:
- Educate ourselves and others on all aspects of water quality and pond management by reviewing the information available to us on this web-site.
- Combat the potential introduction of invasive weeds into West Hill Pond by signing up for the DEEP Invasive Investigator Program and volunteering to monitor boats being launched at the boat ramp (for more information, see Section A, Item 5 below)
- When aquatic plants are found proliferating in your swimming area, reach out and engage either the Trustees of the West Hill Pond Association or members of the WHLSPOA Water Quality Committee to better understand the alternatives for plant mitigation. See alternatives in section B described below.
- Discourage geese from hanging out on our properties.
- Volunteer for the summer secchi disk reading patrol.
- Attend the summer West Hill Lake Shore Property Owner Association (WHLSPOA) meetings.
What Else Is Under Consideration?
A) Investigating and controlling sources of nutrients and plants, which include:
1) Septic system leechate —
a) maintain septic systems in good repair
b) develop and install new septic systems farther away from the water
c) identify and then repair or replace failing systems
d) ensure the regular inspection and periodic emptying of septic systems
e) pay attention to what we place in them
2) Turf and garden fertilizer – can cause algal blooms and promote aquatic plant growth. It is therefore imperative to avoid using products containing phosphates. Better still would be not using any fertilizers at all on lawns near the waterfront.
3) Water Fowl – Droppings mean both bacteria and excess nutrients, so don’t feed the geese and ducks. Feeding them means even more nutrients and more droppings in the water! Hunting waterfowl is regulated at the federal level. For safety reasons, hunting requires a license and permission from neighbors within 500 ft.
4) Watershed management – Stormwater retention and treatment decreases excess nutrients and pollutants, and prevents sand and dirt from entering the lake. Eliminating or minimizing shoal areas where runoff enters the lake will eliminate one source of unwanted plants! These issues are critical for individual landowners, our association and our towns,Potential conflicts and misunderstandings between these parties can be mitigated by furthering efforts to include Barkhamsted and New Hartford town officials in our watershed management activities. Our property values and the Towns‘ tax bases are directly impacted by the quality of WHL water. We all stand to benefit by cooperative efforts to keep our lake pristine.
5) Boat Access Monitoring (and self-monitoring) – The volunteer boat inspection program was started on West Hill in 2012 and exists to assist the DEEP officials. Volunteers are required to be trained by the state and to wear yellow t-shirts that clearly identify them as volunteers. Volunteers strive to educate boaters about invasive weeds and organisms that they may be transferring from another body of water into ours, and to enlist their cooperation in preventing such transfer. Volunteers have no enforcement powers! Their presence is strictly educational / informational. More information is provided by the Invasive Investigator Program: Launch Monitor Handbook—distributed by DEEP at the time of training. Contact: DEEP Police Dispensing phone# 860-424-3333.
B) Considering additional measures (chemical and non-chemical):
1) Decrease nutrient loading – Rooted aquatic plants develop from nutrients that accumulate with sediment on the lake bottom. Working with the towns of New Hartford and Barkhamsted to resolve watershed runoff issues will be necessary to decrease vegetation issues that were identified by the Lenard Engineering report and Stormwater Management Best Practices outlined on this web-site. There is a clear consensus that this is a critical required approach.
2) Weed Suction Harvesting – Requires expertise (divers and equipment) and permits. Removes aquatic plants and sediment which reduces the habitat suitability for many aquatic plants. Like dredging, it is not particularly selective about what is removed – and could be damaging to certain habitat. At greater depths it can remove anoxic soils and reservoirs of nutrients such as phosphorus. Suction harvesting typically uses dewatering bags placed on shore with careful attention to the water directed out of the bag and back into the lake. Conceptually this process would seem to have merit but has not been thoroughly researched or tested. There has been some suction harvesting performed on the lake but the results were not unequivocally positive, and the cost is high.
3) Aquatic Mats – also known as benthic (bottom of the lake) mats are physical barriers placed on the bottom of the lake to prevent plant growth in areas where sediment accumulates from run-off and weeds proliferate . These are placed by divers and are weighted down. The area covered needs to be reasonably level and cannot have much of a slope, so this solution is not appropriate for all areas of the lake.
4) Triploid sterile carp – are fish that eat many types of aquatic plants, including both undesirable and desirable species, though their impact on current fish populations in West Hill is unknown. Since sterile carp can’t reproduce, their population in the lake is controllable. Permits are required for their introduction. These are considered inexpensive.
5) Barley straw is used to inhibit algal blooms – It has to be placed at areas of water entry (such as storm-water runoff areas) before the algal bloom occurs. It has to be placed at inlets 1-3 times per year. This method doesn’t kill the algae. Its use seems unnecessary for West Hill as we presently do not have significant algae issues.
6) Dredging – increases the depth of shallow ponds to promote fish growth, discourage weed growth and increase oxygen levels. The drawbacks include expense, the issue of what to do with the dredged soil and the collateral loss of other organisms. Any work of this nature performed within the Wetland Regulated area would require permitting. This approach is probably not a good solution for West Hill.
7) Winter Drawdown – to freeze problem vegetation disrupts sediments and can be an effective control of most aquatic plants. We have an established drawdown protocol and our dam would require altering to accommodate a drawdown effective for reducing plant populations. A winter drawdown process is not selective and can have a negative effect on plants we might want to retain. This, too, doesn’t seem appropriate or cost effective for West Hill.
1) Herbicides and algaecides – can eliminate specific nuisances but can be expensive and can cause significant collateral damage. They require permits (per Ct General Statutes—chapter 441, section 22a-66z), licensed operators and repeated applications, therefore, significant ongoing costs. Potential problems include oxygen depletion from decaying weeds and negative impact on non-targeted organisms and plants. It would likely be more effective, less expensive and less detrimental to the environment to reduce the flow of nutrients into West Hill (“manage the watershed” — see Section A, Item 4 above).
Background Information and Report Details
West Hill Pond is 261 acres. Its maximum depth is 63 feet with relatively steep sides in the basin. The shallow shoreline where plants grow is narrow. The area around Teddy Bear may be the only area with plants that is not right along the shoreline. Apparently only about 75 of the 261 acres can grow rooted plants, depth being the major determinant.
Categories of aquatic plants
1) Algae – (microscopic, single cells)—Factors that affect its growth are phosphates, pH (alkalinity) and hardness
2) Vascular or rooted plants –
Native species — three of the common plants are large-leaf pondweed, red-leaf pondweed, and tape grass; 8 new species were identified in WHL in 2010 through it is not clear if they were new, or simply not identified previously; water weed has not recently increased in numbers but “has the potential for robust growth.”
Aquatic Invasive Plant Species
[the invasive Curly leaved Pondweed]
Native species are considered good because they are in equilibrium in the environment and typically serve as habitat and food for animal species we seek to retain. In summary, invasive species contribute to the loss of “biological diversity” and overall aquatic habitat degradation, and also from a recreational perspective they interfere with swimming, boating, fishing.
Report SummaryOur water quality continues to be judged as excellent. There were no exotic or invasive species found. Three species (large-leaf pondweed, red-leaf pond weed, and tapegrass) appear to be spreading in areas affected and are more prominent than before. There did appear to be a relationship between dense “plant stands” and storm water entry points, as identified by the Lenard Engineering study. The study also emphasized that monitoring and correcting storm water runoff points, to control introduced nutrients and sediments, should be important for us all!
[click map to expand map view]
1) Phosphorus is the principal nutrient for phytoplankton-algae (the free floating single cells that are suspended in the water and impact its clarity). Water clarity decreases as the phosphorus and thus the algae increase. The algae grow in the top 30 feet (upper ½ ) of the lake. The goal is to keep phosphorus below 10 ppb (parts per billion), although phosphorus levels vary with the time of sampling and the depth at which it is measured.
2) Nitrogen (composed of ammonia, nitrate, and organic nitrogen) plays a primary role in the growth of rooted aquatic plants. Nitrate levels were below detection limits at all depths. Ammonium (derived from bottom sediments and used by the phytoplankton) was also below detection limits. Organic nitrogen (from decay of microscopic plants and from the watershed) was within established ranges.
3) Clarity (Secchi disk method was used for determining visual clarity) depth was greater than 20 feet and was therefore judged excellent. It is important to know that this measure is affected adversely by increasing levels of phosphorus and sediments and that it has varied over time.
4) Dissolved oxygen was judged excellent between the surface and 40 feetAquatic plants –Even though there were no invasive species found, it is important to note that there was concern over the proliferation of both large leaf pondweed and red leaf pondweed. The report states that we need to continue annual surveys to monitor this situation and that we should continue suction harvesting and placing benthic mats to control it. We must also continue to rectify storm water drainage issues at some of the hotspots identified in the Lenard Engineering report.
In addition to survey’s performed annually by our Limnologist, we have been fortunate to be selected by the CT Agrigultural Experiment Station for Aquatic Plant Surveys twice. Below are the reports from those surveys.
CAES 2012 Aquatic Plant Survey
CAES 2005 Aquatic Plant Survey
Additional Considerations for Monitoring
Other Biotic Sampling – Connecticut College has undertaken extensive study of Diatoms and Scaled Chrysophytes throughout the east coast of the United States, including West Hill Pond. Results of their sampling can be found at the Connecticut College Silica Secchi Disk website. Their sampling surveyed 46 Chrysophytes and 37 Diatoms. It will be interesting to dive deeper into the project and literature to determine what changes to those populations might infer. There have been numerous research projects correlating changes in specific Diatom and Chrysophyte communities to changes in water conductivity and other physical factors, which also in some cases, have correlations to aquatic plant communities. Are we equipped to track changes to these communities? Is what it might tell us important enough to warrant the cost? These are the questions we are trying to answer.
Additional Chemical and Physical Sampling – There are lakes in Connecticut (ie. Columbia Lake) that have implemented watershed zoning layers based on a nutrient allocation approach. This is an approach that attempts to evaluate the amount of nutrients the lake can sustain, and the amount released by different areas within the watershed based on land use. A simplistic example is that forests are better at retaining phosphorus than lawns, and lawns are better than dirt roads. Then, by extensive evaluation of the lake chemistry and biology, limnologists are able to predict the amount of nutrients that a lake can sustain without leading to certain types of biotic growth such as algal blooms or support of aquatic plant communities. Knowing that amount allows an easy regression to an amount expected from any watershed area. So for instance, if a lake can sustain 100 pounds of phosphorus per year, and it had a 100 acre watershed, then the expectation is that each acre should contribute no more than 1 pound of phosphorus. We are working with our Limnologists to see if this approach is still considered valid, and if such a model might be able to be applied to West Hill Pond. There is significant work yet to do before we understand both the validity of the approach, the feasibility of raising the funds to pay for the required sampling, and if there are alternatives that can provide an equal or better approach for protecting the lake.
Eutrophicationis the aging process that gradually transforms a pond from a body of water into a marsh and eventually into a meadow or a forest. This process occurs as the pond fills with sediment and vegetation. Symptoms of the process include; algal blooms, increases in vegetation/weeds and depletion of oxygen in bottom water.
We trust that slowing this process by maintaining good water quality is a desirable goal, shared by all who enjoy living near or visiting West Hill Pond. Our environment, our quality of life and our land values are directly impacted by water quality!
Contributed by Pete Humphrey and Steve Unger