Reservoir maintenance, especially dredging, is costly

 

Citizens Water of Indianapolis recently applied to IDEM for authorization (a Section 401 Water Quality Certification) to dredge a large area of Morse reservoir over the next 20 years in order to regain a portion of the original reservoir capacity.   Morse turned 60 years old in 2016 and sedimentation from its tributary stream inlets and adjacent/upstream land disturbances (mostly urban development and agricultural operations) have significantly diminished water-storing capacity.  Citizens proposes to dredge 93 acres plus 4 acres of emergent wetlands.   Over the 20-year project period, it will remove upwards of 360,000 cubic yards of sediment.  Morse has a total surface area of approximately 1500 acres.

I asked Citizens about the cost of the dredging.   It reported:  For Morse, it budgeted $62,000 in 2016, $400,000 for 2017, and $650,000 for 2018.   No estimates available yet for subsequent years’ budgeted costs.   

For Geist reservoir, Citizens spent $504,000 in 2016 and has budgeted $400,000 for 2017.

Citizens Water should be commended for reversing this deferred maintenance and addressing the cumulative problem of capacity loss.  Citizens Water’s predecessor Veolia Water (a private operator), which operated the system under nominal city supervision by a Waterworks Board and staff for about 8 years during the Peterson administration, conducted no capacity dredging at all.   It does not appear that the Indianapolis Water Company/IWC Resources, Inc. which operated the utility throughout much of the 1900s, dredged much if at all.   Update:  Here is Citizens Water’s response to my inquiry– “IWC did dredge 121 acres of the reservoir in the mid-1990s to restore 788,505 gallons of capacity to Geist Reservoir. We do not believe Morse was ever dredged by IWC or Veolia.

Maintenance dredging to preserve capacity should be done periodically/selectively.  The summer drought and heat of 2012 caused precipitous and unsustainable drawdowns of the reservoirs (ridiculously, mostly for suburban lawn irrigation).  In addition, despite the fact that the reservoirs were built as water supply reservoirs, Citizens is bedeviled by the complaints of wealthy and vocal reservoir property and boat owners when water levels fall to the point of impeding boating.   Of course, these recreational reservoir users pay nothing to support the dredging.

In the future, public policy review of any proposed new reservoirs should include close consideration of the full costs of long-term maintenance.  Reservoirs once constructed, immediately begin filling with sediment.  This is exacerbated in agricultural areas where tilling hastens the rate of sedimentation.

As Kurt Vonnegut, Jr. said: “One of the fundamental flaws of human nature is that everybody wants to build, but nobody wants to do maintenance.”

 

 

 

 

 

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