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Home My WebLink AboutAgenda - 11-10-2015 - 6 - Eno River Hydrilla Management Pilot Study Update 1 ORANGE COUNTY BOARD OF COMMISSIONERS ACTION AGENDA ITEM ABSTRACT Meeting Date: November 10, 2015 Action Agenda Item No. 6 SUBJECT: Eno River Hydrilla Management Pilot Study Update DEPARTMENT: Environment, Agriculture, PUBLIC HEARING: (Y/N) No Parks and Recreation (DEAPR) ATTACHMENTS: INFORMATION CONTACTS: A. Hydrilla Verticillata and Eno David Stancil, 245-2510 Infestation Photographs Thomas Davis, 245-2510 B. Photograph of Eno Hydrilla Management Task Force Open House C. Example of Hydrilla Public Outreach Flyer D. Eno River at Pleasant Green Road, August 2012 and August 2015 PURPOSE: To receive an update on the first year of a two-year pilot study examining the management of hydrilla in the Eno River. BACKGROUND: Hydrilla (Hydrilla verticillata) is an invasive aquatic plant native to Asia that was first noted in the United States in the 1960s (Attachment A). Since then, hydrilla has spread rapidly in the U.S., reaching nuisance levels in many locations. Hydrilla has been called "the perfect aquatic plant" because it spreads rapidly, is able to reproduce in four different ways, grows in extremely low light, and is able to crowd out native aquatic vegetation. For many years hydrilla has been present in portions of the Eno watershed, including Lake Orange, Corporation Lake, and the West Fork of the Eno Reservoir. More recently, Eno River State Park staff noted that hydrilla is their "number one resource management problem in the Eno". Hydrilla causes negative water quality impacts, can be harmful to the river ecosystem, and adversely impacts the recreational experiences of people visiting the State Park and elsewhere. Hydrilla can be spread from one water body to another via watercraft or waterfowl. The plant can also be spread by people discarding aquarium materials into waterways. In 2011 the Eno River Hydrilla Management Task Force, comprised of local governments and state agencies, including the Aquatic Weed Program of the NC Division of Water Resources, began planning to address the hydrilla infestation in the Eno River. The Task Force agreed to conduct a two-year pilot study to examine the effectiveness of using a US Environmental Protection Agency-approved herbicide to manage hydrilla in a portion of the river. In April 2015 the Task Force hosted a public information open house in Hillsborough concerning the pilot 2 study (Attachment B). Details were provided on the problem, the results of an Environmental Assessment for the proposed project, and the selection of a contractor to apply and monitor the herbicide in the Eno. Additional public outreach efforts were conducted throughout the watershed (Attachment C). Pilot study herbicide treatments in the Eno River began in late May 2015. Low stream flows over the summer aided in maintaining a consistent concentration of fluridone, the active ingredient in the herbicide, throughout the treatment zone, from Lawrence Road east of Hillsborough downstream to Roxboro Road in Durham. Monitoring of the concentration of fluridone in various locations along the river occurred throughout the duration of the study. Monitoring of native vegetation, snails, crayfish and fish above and within the treatment zone was also conducted before and during the hydrilla treatment. Bleaching of hydrilla was observed after just one week of herbicide treatments. Within four weeks, there was notable reduction in the density of hydrilla in the treatment zone. Further herbicide treatment resulted in dramatic differences in hydrilla density between the treatment area and the untreated area upstream. Nearly-complete removal of visible hydrilla vegetation was reported at locations within the area of treatment (Attachment D). The Eno Hydrilla Management Task Force will continue to evaluate data from surveys of the Eno River ecosystem both within and above the treatment zone. Native vegetation is responding positively. It is anticipated that the results of the first year of the pilot study will be overwhelmingly positive, and that the Task Force will proceed with the second year of treatment. Over the winter months, the Task Force will consider using a lower concentration of fluridone, starting the injection process earlier in the growing season, and adding a second injection location in order to further minimize the apparent impact to native plants. Following completion of the full two-year pilot study, the Task Force will begin to discuss long-term objectives for the management of hydrilla throughout the Eno River watershed. Lastly, the County recently completed a contract with the NC Division of Water Resources for the addition of sterile grass carp to Lake Orange, which is infested with hydrilla. Grass carp are routinely used to help control hydrilla in lakes and reservoirs. FINANCIAL IMPACT: The total cost of this two-year pilot study is $150,000, with the NC Division of Water Resources providing half of the funding. DEAPR has agreed to provide $10,716 for the pilot study. Additional hydrilla management, especially if the treatment area is increased, could require some level of financial commitment on the part of the County after the pilot study concludes in FY2015-2016. SOCIAL JUSTICE IMPACT: The following Orange County Social Justice Goal is applicable to this agenda item: • GOAL: ESTABLISH SUSTAINABLE AND EQUITABLE LAND-USE AND ENVIRONMENTAL POLICIES The fair treatment and meaningful involvement of people of all races, cultures, incomes and educational levels with respect to the development and enforcement of environmental laws, regulations, policies, and decisions. Fair treatment means that no group of people should bear a disproportionate share of the negative environmental consequences resulting from industrial, governmental and commercial operations or policies. 3 This two-year pilot study to manage hydrilla aims to increase access to the Eno River and Eno River State Park for all. RECOMMENDATION(S): The Manager recommends that the Board receive the information presented and provide direction to staff as needed. . Attachment A. Hydrilla, , ■ infestation of e River, downtown ■ e e ■ summer $ -- % r � > - � Hydrilla verticillata - ��\ k � - • � � �� \\ , � �j�. � �� - _ . r - � 5 Attachment B. Eno Hydrilla Management Task Force public information open house in Hillsborough, April 2015 .. or f� � 6 Attachment C. NC State Parks Hydrilla in the Eno trifold flyer, front and back Yaw How Can MIL .7 Cooperative Pa"rtn - HYDRILLA YOU . . the Spread of A. in the HYDRILLA? 1.Educate yourself and others on Hydrilla [W I Wkbonugh `` 2-Report sightings of Hydrilla to Eno River State Parkstaff 3.Clean your boat and equipment ,1 _ _ Nc PC a STEPS to clean your boat • equipment 1.Remove,brush and wash any visible mud,plants,other debris before Center for Aquatic&Invasive Plants transporting. plants.ifas.ufl,edu/ 2.Drain water from boat before going into another water body. NCSU 3.Let boat/trailer/equipment completely www.weedscience.ncsu.edu/ dry out prior to using at another site. aquaticweeds/hydrilla.pdf 4.Check your canoe or kayak storage areas,paddles and carry straps. NC Aquatic Weed Control Program S.Check your fishing pole,gear and bait ncwatecorg/?page=72 bucket for plants,mud or debris. Beforeleaving and befofe launching.,. Southeast Exotic Pest Plant Council inspect everything! se-eppc.org/marival/HYVE.f t-1 l Point of contact FF Eno River State Park .,•,f.� I + 919-383_1696 Praidadnye,•N.C.DHisi.&P.rRS•nd Rwr•.Ui, w —p•r.mn rah NC-D...i ei wow R-..—,enO.rlVer(R7 nCDarkS.�OV Hydrilla Facts Hydrilla r.Current •Even a small fragment of hydrilla can Hydrilla r ► s RIVER grow into a new plant. •Hydrilla is an invasive exotic species (native to Asia). 3 •Hydrilla is one of the worst aquatic - - -• _ weeds in the United States. •It is illegal to transport hydrilla. ;,V,;4ost of the Hydrilla plant is below the surface of the water. 7414, —, Management Strategies re..ar.oe i.a Key Characteristics to look for: Herbicide applications in summer. •Leaflet Number:3-10 leaves per whorl Effects of Hydrilla •Leaf Margin:Finely serrated Selected herbicides are: •Leaf/Leaflet Shape:Oblong •Approved by the EPA for aquatic sites. •It has the potential to negatively •Leaf Length:1/3—1/2 inch •Pet safe/non-toxic to fish. impart fish communities Imo^1_;1 �4 s'''a'''�' 8 '9' ' •Do not restrict recreational activity at •Interferes with recreation(boating, ' application rates. fishing and swimming) •Harmful to native aquatic communities Hydrilla Is invading North Carolina and it •Reduces water flow can overwhelm waterways after only a •Loss of property values and tourism \ few growing seasons3 •Harbors toxic cyanobacteria that leads 42 f to bird deaths from AVM People play a critical role in preventing, detecting and reporting new infestations. 7 Attachment D. Eno River near Pleasant Green Road, August 2012 (top) and August 2015 (bottom), illustrating the effect of fluridone treatment IN Ave � �'` i • - r ��H�:'ir IS, f �aft 1 _ r E'