HomeMy WebLinkAboutWPO201000068 Other 2019-05-29Hirschman Water & Environment, LLC
Stormwater Management • Environmental Training • Environmental Policy/Planning
Memorandum
Date: May 29, 2019
To: Hunter Wood, United Land Corporation
From: David J. Hirschman
Hirschman Water & Environment, LLC
Re: Aquatic Bench at Hollymead SWM Facility #1
I inspected the aquatic bench of the subject pond on May 22, 2019. This memo concerns the conditon
of the aquatic bench vegetation in reference to the original approved planting plan from 2015.
The original plan listed the following species:
• Pontederia pectinatus (Pond Weed)
• Valisneria americana (Wild Celery)
• Elodea canadensis (Waterweed)
These species were never planted on the aquatic bench, and a more naturalized plant community has
colonized the bench. This, utlimately, is a good thing, as the original plant list contains non-native and
potentially aggressive plants that could become a maintenance issue in the future, not just for the
bench, but for part of the pond surface as well. Among the original plan species are rooted aquatic
plants, more accustomed to growing in deeper water, and they may not have done well along the
shallow bench.
The plants that have colonized the bench are a mix of native and non-native wetland -type species that
are common in this area. There are two dominant species along all areas of the bench, both of which
are native to the region:
• Schoenoplectus tabernoemontani or validus (Soft -Stem Bulrush)
• Carex lurida (Lurid sedge)
Both of these species are well -established and well -adapted to the aquatic bench environment.
Other less widespread species found along the bench include:
• Typha latifolia (cattail — can become invasive/aggressive, but currently there is not a lot at this
site)
• Ludwigia palustris (Marsh purslane — not native to the area, rooted aquatic)
• Potamogeton perfoliatus (Clasping leaved pondweed — not native to area)
11.07 Calhoun Street, Charlottesville, Virginia
P: (434)409-0993 • Email: daveRhirschmanwater.com • www.hirschmanwater.com
Hirschman Water & Environment, LLC
Stormwater Management • Environmental Training • Environmental Policy/Planning
• Scirpus cyperinus (Woolgrass — native to region)
Other species may become evident during other parts of the growing season. In general, the vegetative
coverage is good and should be sustained along the aquatic bench in future years.
It should be noted that on the date of my inspection, a section of the bench along its eastern edge had
been weed -whacked. Mr. Wood caught this activity before it became more widespread. I do not expect
the weed -whacking to affect the long-term health of the bench, as these species are still rooted and
should grow up fully during the current growing season.
I would recommend allowing the existing plant community to evolve and not remove species or replant
at this point in time. In terms of non-native or potentially invasive or aggressive species, I would
continue to monitor the Typha latifolia and the other non -natives. At present, there is not a need to
remove these, as they have not become widespread. The future concern would be if they start to take
over or crowd out the other native species.
In summary, my key finding and recommendation is to let the existing plant communtiy continue to
evolve, as it constitutes a good aquatic bench community. In the future, it may be necessary to
undertake some maintenance tasks to maintain a healthy plant community.
i1-07 Calhoun Street, Charlottesville, Virginia
P: (434)409-0993 • Email: dave[a hirschmanwater.com • www.hirschmanwater.com