Lake Bluff has been receding at a rate of about 1.8 feet per year according to research of maps and records dating as far back as 1846. Pounding Lake Ontario waves have continually eroded the toe of the 100-foot Bluff, while the combined effects of wind, rain and freeze-thaw cycles have eroded the Bluff face. Consequently, only fourteen of thirty Victorian-style cottages originally constructed on Lake Bluff in the early 1880’s remain today. Of these fourteen, only three exist on their original lots. The other eleven surviving cottages have been relocated to escape the receding edge of the Bluff. Sixteen of the original thirty cottages have been lost because they could not be moved and were either demolished or fell over the edge.
To prevent further loss of this historic property, Lake Bluff property owners began planning a shoreline stabilization project in the late 1990’s. The nationally prominent and Syracuse-based engineering firm of O’Brien & Gere was hired in 1998 to design the project. O’Brien & Gere, in turn, retained the consulting services of Professor Sam Clemence of Syracuse University’s civil engineering department, an internationally recognized expert in projects of this nature.
The project was divided into two phases. Phase 1 would be a rock revetment, 925 feet long and 20 feet off-shore, to protect the toe of the Bluff from wave erosion. Phase 2 would involve grading and vegetating the face of the Bluff. After a lengthy regulatory permitting process, including preparation of a 98-page environmental impact statement, work on Phase 1 began in the fall of 2001. By the time Phase 1 was complete later that fall, more than 10,000 tons of armor stone – each weighing one to two tons – had been placed along the base of the Bluff. These large armor stones were anchored on a 2-foot base of 100-200 pound stone trenched 6 feet into the lake bed. The crest of the revetment was designed to be about 4˝ feet above the mean high water level of Lake Ontario.
Over the next 7 years (2001-8), the face of the Bluff continued to erode and this back-filled the 20-foot space behind the revetment. Phase 2 of the project then commenced in 2008. Preliminary work included tree removal, power line relocation, and re-design of several septic systems. Because all work would be done above the lake water level, permitting jurisdiction belonged to the Town of Huron which was considerably more straight-forward than dealing with the multiple state and federal agencies involved in Phase 1.
After seeking proposals from at least six contractors, Canastota-based Abscope Environmental Inc. was hired to undertake the massive earth-moving job of shaping the rugged and rock-hard face of Lake Bluff into a smooth slope. The bottom two-thirds of the surface would be graded to a 2:1 (horizontal:vertical) slope while the top one-third would be between a 1:1 and 1.5:1 slope. Groundwater seeps at the top of the Bluff and at a few locations midway down the face of the Bluff also required drainage by trenching and pipe installation. Abscope’s excavation and drainage work began in the fall of 2008 and continued, after a winter-spring break, through the summer of 2009.
The vegetation component of Phase 2 was performed in 2009 under the direction of LandSource Organix of Milton, Ontario, Canada. The LandSource design called for a 2-inch thick covering of the proprietary EcoBlanket green-waste compost material to be pneumatically applied over the graded face of the Bluff. The compost contained a “3-tiered” seed mixture of: (1) rapid germinating grasses, (2) longer-term deep-rooted grasses, and (3) several deep-rooted shrub varieties. This mixture was specifically designed to be compatible with the chemistry of the Bluff glacial till which has a high ph of 8 and almost no organic matter. Coconut fiber koir matting was first anchored to the uppermost steep slope to provide a matrix to which the compost could adhere as the grasses took root. This matting was not needed on the lower 2:1 slope, though erosion control matting was installed over the compost along the shoreline to provide protection from wave splash. Because of cross-border regulatory issues, the Canadian LandSource company subtracted the compost application work to Superior Ground Cover, Inc. of Hudsonville, Michigan.
The final element of the project was a 3-zone sprinkler irrigation system, designed and installed by Irrigation Tech of Rochester. Germination of some of the grasses was realized within a few days of the compost application in late August 2009.
Heavy rains and groundwater seepage caused a few localized slope failures in the fall of 2009 and again in the spring of 2010. These were repaired with rip-rap stone in an area of intense groundwater and with a fresh covering of seeded compost in other areas. Rows of willow live-stakes and plugs of switch grass and dune grass were also planted immediately below the rip-rap stone for additional soil stabilization.
As this article is being written (June 15, 2010) the Lake Bluff project area is lush with vegetation. There’s good reason to be optimistic today about the ultimate success of this long-term project. Some localized repair work may be needed from time to time. Never the less, it is a relief to put the tape measures away and to no longer worry about the once-annual ritual of measuring how much of the Bluff has fallen off each spring.
Tom Cassel
6/15/10
Phase 1Revetment Construction in 2001
Phase 1 Armor Stone Revetment (2001)
Phase 2 Slope Excavation (2008)
Phase 2 Staging -- Finish Grading, Koir Mat Installation, Irrigation System Installation, and Seeded-Compost Application (2009)
Phase 2 Project Completed and Beginning of Grass Germination (2009)