Lake Naticook Milfoil Update

Park & Rec: June 19, 2013Town Council: June 29, 2013

Variable Milfoil

The Threat to Lake Usage

File photo: Milfoil with seed pods, being chopped and dispersed.Grows an inch a day to 6-8 feet tall. Grows under ice. Survives winter exposure.Spreads by fragments introduced by boats/trailers, or floating fragments

Lake Naticook 2012 History• Discovered July 2, 2012• State Survey July 9 showed 5 acres of milfoil

• Sept 22 survey showed 20 acres of milfoil• Oct 11: Town Council authorizes P&R to close

the town boat ramp to slow the disturbance & spread of milfoil until successful eradication.

July 9, 20125 Acres

Sept 17, 201220 Acres

Treatment June 4, 2013• 24 acres Treated with

Renovate Max G Herbicide

• Initial survey shows improvement but not total eradication

• Hand harvesting by State divers planned as practical

• Fall chemical treatment may be needed

Funding Implications

• First year of treatment is funded by NH DES– Three diver trips in 2012– 25 acre treatment June 2013– 2-3 diver trips in 2013– Fall treatment if necessary

• Follow-on treatments subject to grant funding of up to 50%

Approx $20K to date

Successful treatment help mitigate future local costs

Treatment Challenges• Significant use of Veterans Park boat ramp from ice-

out to June 3 caused lots of milfoil fragments to disperse around the lake– One resident pulled 20 floating fragments on a Sunday

afternoon and probably missed many more• Usage included:– Canoe/kayak activity– Carry-in motor boat activity– Swimming– Dogs swimming to retrieve balls in the milfoil area

Treatment Positives• Excellent coordination with State DES, YMCA, and

treatment contractor to coordinate:– As late as possible treatment (for best effectiveness)– 2 weeks before Camp Sargent opens for swimming– Delay of Camp Sargent Triathlon from June 2 to June 23

• Large resident turnout for milfoil education & weed watcher training.– Lake is divided into 7 zones with 14 groups of people

volunteering to monitor, mark and report milfoil.

This is an ongoing process

Source: Long Term Variable Milfoil Management Plan forLake Naticook, NH Dept. of Environmental Services February 2013

2013 Path Forward• Maintain vigilance– Lake Naticook Conservation Association members are

trained and working to identify remaining milfoil– NH DES validates finding and schedules treatment

• Maintain preventative measures– Keep boat launch closed to motor boats until the NH

DES milfoil survey documents eradication in the area of the boat launch

– Improve communication at boat launch with signage if closure is maintained

Longer Term

• Apply for grant for 2014 treatment if needed– Up to 50% available from NH DES

• Budget matching funds for 2014 treatment• Consider NH Lakes Association Lake Host

Grants– Funds available for P&R or Town to staff a lake host

at the boat ramp to inspect & educate boaters

Interesting boat ramp usage observations

• On an average spring two day weekend:– 15 transient motor boats (2012 observation) – 15 transient non-motor boats (canoes, kayaks,

sailboats)– 18 long distance swimmers– 20 people & 4 dogs at the water’s edge

Truly a town / regional resource that gets used and enjoyed