Although most members join the Chicago Botanic Garden to enjoy the flowers, water is as integral to the Garden’s special beauty as the 2.3 million plants in its collection.
The Garden has nine islands and nearly one-quarter of our 385 acres is water. We have 81 acres of water, including 60 acres of lakes, the Skokie River, several wetlands areas, and over 5.7 miles of lake shoreline, of which slightly more than half has been restored to repair erosion and improve aquatic habitat. I deeply appreciate the efforts of state and federal elected officials who are working to secure funding that will allow us to restore another 2.6 miles of degraded shoreline. This funding will allow us to protect the Garden’s islands and the aquatic plant and animal communities that depend on the habitat they provide.
Last September, Illinois experienced a storm and flooding so severe we had to close the Garden for four days. This event is a powerful example of the need for effective stormwater management practices. When there is unusually heavy rain, the Garden accepts excess Skokie River water over its north weir—effectively flooding itself—to help protect downstream Cook County communities. The Garden retains this water until the flood crests, waits for the water to recede to safe levels, and only then do we allow water to be released from our lakes. Last September, when the water levels rose 6 feet, covering the Garden’s intersections and bridges, the Garden prevented more than 100 million gallons from traveling south during the height of the storm, thereby reducing the severity of flooding in downstream communities. This practice is one that we follow without exception—out of legal regulation and civic responsibility. I am grateful for the effective leadership Cook and Lake County officials have provided for addressing important stormwater management issues.
Stormwater issues that municipalities everywhere grapple with are problems caused by human development. Native landscapes store rainfall in naturally occurring depressions where plants help to filter and absorb it for the benefit of the ecosystem in which it fell. But buildings and other impermeable surfaces such as parking lots and roads have significantly altered our landscapes. The result has been the need to replace efficient natural systems with manmade sewer systems that are increasingly overwhelmed. Even the smallest amount of rain must now be diverted to sewers and piped away, often somewhere far from where it fell, and where it is often (but not always) processed to remove chemical impurities before it is released.
The new Daniel F. and Ada L. Rice Plant Conservation Science Center will have very important tools for demonstrating two very effective stormwater management practices. The Rainwater Glen, a below-grade garden surrounding the building, will function like a river’s floodplain. It will hold back stormwater runoff, allowing deep-rooted native plants to facilitate absorption and help to filter impurities. The Rainwater Glen will contribute to improved water quality at the Garden and, importantly, in each of the ecosystems it will eventually flow through.
The Ellis Goodman Family Foundation Green Roof Garden South and Josephine P. & John J. Louis Family Foundation Green Roof Garden North will each have a semi-intensively planted green roof that are designed to reduce the immediate demand placed on the Rainwater Glen during rainstorms. Rainfall will be absorbed and temporarily stored in up to 8 inches of special soil and in specially designed storage channels beneath the soil.
The next time you visit the Plant Science Center I encourage you to visit the Green Roof Gardens and Rainwater Glen where, once the building is finished, interpretative signs will explain the benefits these gardens provide and demonstrate the Garden’s commitment to creating awareness of stormwater management practices our research is actively working to improve. If you are not already registered, I invite you to join the special July 21 hard-hat tour of the Plant Science Center for President’s Circle members.
The pleasures water provides come with the responsibility for protecting and effectively managing it. I am indebted to you, the President’s Circle members, for your ongoing support. Your generosity allows us to fulfill the Garden’s mission of promoting the enjoyment, understanding, and conservation of plants and the natural world, including, of course, our water.