Lake Shoreline Erosion Control
and Habitat Enhancement

The Chicago Botanic Garden and the U.S. Army Corps of Engineers’ Ecosystem Restoration Program completed a ten-month Section 206 Ecosystem Restoration Project on 1 1/4 miles of shoreline around the Garden’s North Lake. The entire perimeter of the Regenstein Fruit & Vegetable Garden, as well as areas along the North Lake’s western and northern shoreline were restored. Read more about the project here.

PHOTO: View of shoreline

Embracing Native Landscaping Principles

In recent years, lake educators and managers have encouraged lakeshore residents to resist traditional societal pressures to have neatly groomed shorelines — and instead to embrace native landscaping principles as a way to reduce shoreline erosion and enhance aquatic habitat. And while we've made some progress to revitalize the ecological health of our lakeshores, such environmental sensitivity is clearly the exception rather than the rule. This shoreline section of the Garden's website has been designed to explain environmentally sensitive approaches for restoring and protecting lakeshore ecosystems. Among other things, it explains shoreline erosion and aquatic habitat enhancement techniques installed along the Chicago Botanic Garden's lakeshore through a partnership with the Illinois Environmental Protection Agency and the U.S. Environmental Protection Agency under Section 319 of the Clean Water Act.

Map of the Garden
Water areas at the Chicago Botanic Garden
(60-acre system of lakes shown in blue)

Of the Garden's 385 acres, nearly one-quarter (81 acres) is water. A 60-acre system of lakes winds throughout the gardens and research facilities. About 5.7 miles of shoreline encircles the Garden's lakes, so it is not surprising that the Garden is keenly interested in protecting its shoreline soils and enhancing aquatic habitat.

Identifying shoreline Problems

A 1998 study of shoreline conditions revealed that 80 percent of the Garden's lakeshores were experiencing moderate to severe erosion. In 1999, the Garden completed an Illinois Clean Lakes Program Diagnostic/Feasibility Study. This comprehensive study investigated existing lake quality problems and their causes, and identified remedial measures to restore and protect the lakes' water quality and aquatic habitat.

The problems documented in the Clean Lakes Program study were not unusual or unique for lakes in urban settings. Steep shoreline slopes, weakly rooted nearshore plants (often turf grass), and poor soils dominated the lakeshores. Excessive nutrient loading (primarily from nuisance levels of Canada Geese), as well as rough fish activity (primarily carp) and invasive submerged plants (primarily curlyleaf pondweed, and more recently, Eurasian watermilfoil) contributed to degraded water quality.

PHOTO: shoreline problems

Finding Environmentally Sensitive Solutions

The Garden embraces the philosophy that "a lake is a reflection of its watershed," and all of our efforts are guided by watershed management principles that strive to prevent water resource problems at their source of origin, together with the use of environmentally sensitive approaches that provide sustainable, long-term solutions. By controlling water pollution at its point of origin (for example, by reducing nutrient and sediment runoff from urban development sites, or preventing soil erosion from occurring along lakeshores), we can improve the quality of our water resources most efficiently and effectively. For an excellent introduction to watersheds and how you can restore and protect them, visit the Conservation Technology Information Center's Know Your Watershed website.

PHOTO: restored shorelineIn June 2000, the Garden began restoring its most critically eroding shorelines. Wetland habitats along the lakeshores — previously measured in inches — now expand out from the lake edge by 30 feet or more. Innovative bioengineering approaches for creating stable, shallow-water "shelves" along the shoreline allow water-loving plants to flourish and anchor shoreline soils. These approaches are in contrast to traditional approaches that rely solely on "hard edge" techniques such as sheet piling or impenetrable masses of stone riprap. Creative uses of interplanted stones and boulders, as well as specialized plastic mesh and webbing materials, further help stabilize the shoreline edge and protect our newly installed aquatic plantings. Both private and public funds have been used to support the Garden's ambitious efforts, including significant assistance from the U.S. and Illinois Environmental Protection Agencies' Section 319 Nonpoint Source Pollution Management Program, as well as the U.S. Army Corps of Engineers' Section 206 Ecosystem Restoration Program.