Griffy Lake Closed to Boating June 13 and 14

Bloomington, Ind. - The Bloomington Parks and Recreation Department announced today that Griffy Lake will be closed to boating from June 13 at 7 a.m. through June 14 at 1 p.m.

According to Bloomington Parks and Recreation natural resources manager Steve Cotter, the lake will be closed during, and for 24 hours following, the application of an aquatic herbicide being used to control invasive Eurasian watermilfoil that has become established in Griffy Lake.

Native to Europe, Eurasian watermilfoil forms thick underwater stands of tangled stems and vast mats of vegetation at the water's surface. In shallow areas the plant can interfere with water recreation such as boating and fishing. In addition, densely matted beds of this invasive species displace native plants, and have negative impacts on fish populations and water quality.

Griffy Lake was last treated for Eurasian watermilfoil in 2009. The lake was drained to facilitate repairs to the dam in 2012-13, while a dredging project on the east end of the lake near the boat ramp during that time helped reduce the presence of Eurasian watermilfoil. An invasive plant survey at Griffy Lake in May 2016 revealed that Eurasian watermilfoil has made a comeback at Griffy Lake, mostly on the lake’s east and north ends, and at the time affected more than 22 acres of the 109-acre lake.

Cotter said, “Eurasian watermilfoil reproduces through stem fragmentation, so a single segment of stem and leaves can take root and form a new colony. Fragments can ‘hitch’ a ride on boat propellers, and in live wells and bait buckets, and easily spread to other bodies of water.”

Cotter said the herbicide being used (active ingredient Butoxyethyl Ester of 2,4-Dichlorophenoxyacetic Acid) will have a minimal impact on native plants.

The Parks and Recreation Department hopes that, with Eurasian watermilfoil removed, native plants will have the opportunity to take root in the lake bed and prevent the Eurasian watermilfoil from overcoming the lake in the future.

Bloomington Parks and Recreation will pay Aquatic Control, Inc. $17,100 for the treatment.

###