Reservoir

August 02, 2021

I was amazed by the changes I saw at the city reservoir last week.  I have been consistently fishing the lake for the last three years but have not been there for several months.  Late last year the city put in information kiosks (one notice posted) and did rock work to form small patios on both sides of the boat ramp.  The road leading to the ramp has always been dirt, and even graded it consistently had ruts from the small spring that seeped out of the hillside.  When I arrive last week, I was surprised to see asphalt leading away from the highway.  As I turned, I saw the parking lot had been paved, drainage installed to whisk away the water from the spring, and the rock patios were now lined with rock benches.  They had spent a lot of money to make this a quality boat ramp and lake access.  The changes looked nice.

When I looked online, I found the difference between a lake and a reservoir is whether it is natural, or human made.  Reservoirs are different sizes and used for different purposes, but all have two things in common.  First, humans take water from the reservoirs when we need it, causing the water level to change in different ways than natural lakes.  Second, the dams that create reservoirs can prevent or limit species movement, both upstream and downstream, by the way they alter the flow of water.  Humans have built so many big dams that only one-third of the world’s longest rivers flow freely.  The rest have at least one dam.  Areas like Texas have limited natural lakes, but the rivers have been dammed to create thousands of reservoirs.   Minnesota’s “land of 10,000 lakes” are actuality 11,842, and most of the lakes are natural.  Minnesota’s lakes allow free species movement while Texas’ do not.

Since our reservoir is used for drinking, the water has a strict ban on swimming and gas-powered motors.  These regulations are in place for most small reservoirs, although larger reservoirs allow one or both.  While I understand the gas ban, the swimming ban always seemed odd.  Fish obviously swim in the water (among other things).  The water is also filtered and purified prior to being pumped through the pipes that bring it to individual households.  We have only recently overcome the “boil” order that was on our system for as long as Melissa can remember.  I guess the improved water quality prompted the improved access.  I noticed that as new as the changes were at the reservoir, someone had already backed into a bench and broken the rock top off.  Nice only seems to last so long.

Thoughts:  The changes created by a human-made reservoir influence the species that can live in the ecosystem.  While we have ideas for reducing the effect of dams and reservoirs on our river ecosystems, governments have not kept accurate records of where they are.  Scientists and researchers are trying to track down each reservoir on the planet, creating a GPS reference called the Global River Obstruction Database (GROD), while Europe is using the Adaptive Management of Barriers in European Rivers (AMBER) smartphone app.  If you build it, they will come.  At least the app cannot be rammed by a truck.  Follow the science.  Change is coming and it starts with you.