Let’s Talk about Dams Part 1

Fresh off a recent presentation to the Spring Creek/ Flint Creek Watershed Partnership, I thought it might be a good time to post to the Illinois Lakes Blog regarding the subject.  Regardless if you are for or against them there is no doubt that dams are another set of aging infrastructure within the United States and there is little or no money directly available to remove or repair (more specifically public structures), leaving the unenviable “wait and see” circumstance.  This is Part 1 of a 2-part posting.

The oldest “registered”dam in the State of IL is the Fordham Dam in Rockford, on the Rock River listed as completed in 1852, although there are several on the Fox that are believed to be older with no official dates to confer.  The largest dam in the U.S. is the Oroville Dam which was the center of attention earlier this year when 180,000 people were evacuated downstream of the dam due to the potential threat of dam breach in February:  http://www.mercurynews.com/2017/05/18/oroville-dam-timeline-100-days-of-drama/.  There are an estimated 75,000 dams impounding 600,000 miles of river or about 17% of rivers in the nation.  7% of the nations total energy budget is still driven by hydroelectric power.

What the above total does not account for are the lesser dams which may not even appear as a dam to the unknowing eye.  In the State of Illinois along, estimates range in number of some 5,000  to 10,000 dams which fit this criteria.  The numbers range because the vast majority of dams remain unregistered.  Dams vary greatly in function and size, from impounding of reservoirs for stormwater management to impounding a lake for the purpose of hydroelectric power generation.

The State of Illinois Dam Safety Program officially began in 1980 as Public Act 91-1062.  This was briefly amended in 1983 and has remained largely intact as such to this day.  The program essentially classifies dams based on the perception of risk and potential for downstream damage, property loss, and loss of life.  This allows for a means to require individuals, corporations, governmental agencies, etc to inspect and maintain their dams.  The full Illinois Dam Safety Program can be viewed in greater detail here:  https://www.dnr.illinois.gov/WaterResources/Pages/DamSafetyProgram.aspx.

To keep this blog article somewhat relevant to lakes it may be best to keep the discussion centered around the impoundment of lakes and streams.  Within this context, a general  understanding of the basic safety guidelines and the possible environmental impacts of run of the river dams is useful.  Dams like anything else require maintenance.  Unlike infrastructure like roads and sanitary sewer they are unfortunately an afterthought to owners without the prodding of regulatory agencies.  The problem is that to many dam owners, the risk of eventual failure and downstream impact is minor in comparison to the economic impact of recurring maintenance.

To this end all registered dams must undergo a schedule of recurring inspection that is based on the assessed risk associated with the dam failure impact.  This is not necessarily unique to the state of Illinois.  The inspection must be photo documented and approved to meet the requirements of the state’s inspection protocol.  Any deficiencies are to be documented and slated to an improvement schedule also approved by the state.

While ILMA has been unable to receive a direct answer from the state regarding where the liability rests for a failure on an unregistered dam, insurance companies may opt to have dams inspected to determine rates for HOA’s, lake associations, lake districts, or other agencies who maintain or own them.  There appears to be a fine line between wanting to inspect on your own schedule or giving the state the jurisdiction to set the schedule.  It is quite possible that their are non-registered dams that undergo no inspection at all and also possible that landowners have no idea that a possible structure on their proper may qualify as a dam, and the inherent risk that may be associated with it.

By it’s very definition a dam can have quite a variable meaning.  Based on communication with State of Illinois Dams Division Head Paul Maurer, a dam is basically anything that impounds water, more from an artificial sense (manmade vs natural).  From a consulting standpoint approximately 1/3 of the dams that I have been personally involved with from a repair or inspection standpoint would be classified as a dam and were unregistered.  The owner either inherited the structure or it has always been unregistered and the owner has had no interest in getting it registered.  In the event that the structure should need repair, the registration may take place as part of the permitting process.  The process of registration in itself is not altogether pleasant as the owner must take it upon himself to hire qualified personnel to study and inspect the dam to properly rate and assess the condition.

Part 2 we talk more about the environmental issues surrounding dams.

~p0sted by Admin

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