Aquatic Plant Management in 2014

The results of the Riparian Owners survey in 2014 clearly showed that one area people were not satisfied with is the amount of weed growth in the waterway. The APM Committee is charged with managing this and we’re not satisfied either.

In 2014 we implemented some new approaches and made adjustments to existing processes. We continuously face obstacles trying to balance the needs of boaters, fisherman, budget and WDNR regulations. In addition, the highly nutritious muck that is filling our waterway provides an excellent growing environment for the plant population.

The tools we have available to us include:

  1. Herbicidal Treatments
  2. Manual Weed Pulling and Raking
  3. Weed Harvesting (Cutting)
  4. Weed Harvesting (Hydraulic)
  5. Prevention and Monitoring

 

Herbicidal Treatments

There are two basic types of herbicidal treatments during the season, Aquatic Invasive Species (AIS) and Navigational. The approaches, herbicides and regulations vary between them.  Both are covered by the same permit which we apply for each spring. The AIS treatments begin with a survey of the waterway. The most common AIS found in our waters are Eurasian Water Millfoil (EWM) and Curly Leaf Pondweed (CLP). Wherever these are found, the WDNR allows us to treat them. This season we found over 60 acres. This is the only widespread treatment permitted. At the end of the season, the survey is repeated to assess the impacts.

In 2014 we received approval of our grant application from the WDNR to help with the costs of the AIS treatments. This was the culmination of over a year of work on the application and provides up to $57,000 for AIS control over 3 years.

As the season progresses we schedule treatments on an as needed basis for navigational needs. These treatments target indigenous plants such as Coontail and Elodea. As these grow naturally in our waterway, the WDNR limits us to where we can treat. We are restricted to providing navigational lanes, 30-50 ft wide to piers. We cannot treat past the pier head, along the shoreline, where no pier is present or broad areas of a bay or lake. Navigational treatments such as these are less effective in the shallow waters of some of the bays. We have been working with the WDNR on the use of a new herbicide (Clipper) that has shown better results. This was used with some success in limited areas in 2013 and we expanded its use in 2014. Our hope is to use this in all areas in the future, pending WDNR approval.

One plant we struggle with is Lily Pads. Treatments to prevent them are expensive and vary with their effectiveness. As these are indigenous plants, we can only treat navigational lanes and they grow back quickly. I encourage you to get out there in your waders, or in your canoe and start pulling them out. Individual homeowners can do this around their shore and pier without a permit.

These treatments vary in their effectiveness. If you take a look at satellite images in Google you can see the lanes that have been treated. However, they do not last long and are expensive. The shallow areas allow the new plant growth to reach the surface quickly, and the muck washed in from farms and golf courses up river, as well as runoff from homes, provide a very fertile environment for the plants.

Manual Weed Pulling and Raking

A new approach was tried this year to control weeds in a shallow area in Island View Bay. A company was hired that has scuba/snorkel divers in the water, hand pulling the weeds. These are ferried in bags to the shore by volunteers, emptied into wheel barrows and disposed of. In a 6 hour period, an area in front of three lots, approximately 50ft out from the piers was cleared. We will be monitoring this area for regrowth into next season.

This type of manual pulling, along with the use of a water weed rake appears to be effective and is a good replacement for a gym membership. An individual homeowner can do this along their shore and 50 ft from their pier without the need for a permit. For those of you that have Lily Pads I highly recommend you get in the water and pull them out, including the roots.

In August we recorded a kayak trip along this same area to see how the area was holding up. You can watch that trip below.

Weed Harvesting (Cutting)

In 2012 we experimented with a small trial of weed cutting. The results were inconclusive because, we believe, the trial was too small.
In 2014 a larger weed cutting trial was done in Buena Lake. The permit we received restricted the area we could harvest to a ‘Water Ski’ loop in Buena Lake as well as navigational lanes around the perimeter.

WDNR restricts harvesting in areas where the water is shallow. Also, we are limited to cutting to one foot above the bottom of the lake. If the area being harvested only has three feet of water, we can only cut the top two feet off. Also, once the depth gets to be less than three feet we cannot harvest.

Results of the harvesting done the week of June 23rd show mixed success. In the four days of harvesting, using two harvesters, over 50 truckloads of weeds were removed. Areas with more depth have held up reasonably well, but the shallower areas are poor. At this point we are planning on repeating this trial next year and asking the WDNR to allow us to harvest wider navigational lanes.

At the end of August we did a kayak trip along the eastern shore of Buena Lake, you can see the video of that trip below.

Weed Harvesting (Suction)

Suction Harvesting is an approach that has not been considered in the past. This uproots the targeted plants and their rooting system and feeds them into a vacuum hose that brings them to the harvester where they are stored in bags for disposal. The advantage of this process is the complete removal of the targeted plant as opposed to trimming of the weed plant.  The hope is that this approach will lead to less regrowth in the following seasons.

We are currently working with a new contractor to test the effectiveness of this. We completed a one week trial in the channel north of Elm Island Drive in early August. The treated area is shaded in green in the map to the right.

At the end of August we toured the area in a kayak and posted two videos, one going eastbound filming straight ahead and one going westbound filming down into the water. The kayak trip is marked on the map in red. You can see them both below.

Channel North of Elm Island Drive, traveling eastbound

Channel North of Elm Island Drive, traveling westbound

Prevention and Monitoring

In addition to the plant management programs listed above, we have two activities aimed at prevention and monitoring.

The Clean Boats, Clean Waters program (CBCW) began in 2013. This is funded by a grant from the WDNR and supplemented with volunteer hours. Boat inspections are performed most weekends at the Library Launch. Boats entering and leaving the water way are inspected for any invasive species. Boaters are educated on AIS and data is collected about where the boats have been and the other water bodies they visit. This data is entered into the WDNR Database (SWIMS).

The Citizens Lake Monitoring Network (CLMN) is staffed with WWMD volunteers. These individuals visit specific areas on the waterway on a regular basis and monitor for AIS. Data collected is also entered into the WDNR Database.

Conclusion

A healthy waterway needs plant growth. The goal of the APM Committee is NOT to create a waterway that resembles a swimming pool. The plants support the fish population which leads to a diverse wildlife population. The problem comes when the amount of plant growth reaches a point that inhibits other uses of the waterway.

As you can see from the above we are trying some new approaches to managing this growth. In addition to regulatory and budget constraints, the main issue we face is related to the amount of sediment and lack of depth. If there are only a couple of feet of water, any approach we take will have limited success as regrowth reaches the surface very quickly. Further compounding the problem is the fact the sediment, in some areas there are several feet of it, is highly nutritious and supports abundant plant growth.