Spillway

September 14, 2021

After stopping for a doctor visit last week, we had browsed through the big outdoors warehouse located a few blocks south of the office.  While we were mostly killing time waiting to go out to dinner with friends, it is always fun to watch the fish and dream about fishing gear.  Melissa surprised me by deciding she would like to look at the flies.  While I already have most of what I use, she thought it would be fun to buy some odd patterns and colors to see if they would work.  I suspect all the flies in the store must work somewhere.  While the warehouse says they are “hand-tied,” I also know they are mass produced by people.  I doubt the store would buy flies that did not represent some sort of insect, or that people would tie a fly the store would not buy.  I was thinking that perhaps one of these new flies might work on the spillway I like to fish.

When I looked online, I found the definition for a spillway as “a structure used to provide the controlled release of flows from a dam or levee into a downstream area, typically being the river that was dammed.”  While dams may have bottom outlets with valves or gates which operate to release flood flow, most also have an overflow spillway located at the top of the reservoir pool.  The two main types of spillways are controlled and uncontrolled.  A controlled spillway has mechanical gates to regulate the rate of flow and the design allows nearly the full height of the dam to be used for water storage year-round.  An uncontrolled spillway does not have gates, and when the water rises above the lip or crest of the spillway it is released from the reservoir.  The storage volume of the reservoir can only be used for temporary storage and the rate of discharge is controlled by the depth of water above the spillway.  Most of the earth or rockfill dams constructed by the Army Corps of Engineers are an intermediate type, with normal level regulation of the reservoir controlled by mechanical gates and an auxiliary emergency spillway acting as a safety valve.  Technically, the spillway I fish is a gate, but fisher people (and me) generally call both by the generic name spillway.

Melissa felt like getting out over the weekend and suggested we go up to Blue Mountain.  It was supposed to be cooler, and she thought we could find some shade and do some fishing.  This was the go-to reservoir I thought about fishing while Melissa was buying flies.  There are always fish in the spillway.  When we pulled in the volume of water coming from the tube was low from the lack of rain, with just a small stream coming from the mouth rather than the usual river.  Undeterred, I cast my trout magnet into the pool and quickly caught four fish.  Interestingly, each was a different species, a bluegill, crappie, channel cat, and a drum.  While I caught four fish, I saw several Gar that were over three feet (1 meter) long.  The water was so low I also snagged on the rocks that breakup the usual flow of water and reduce erosion of the spillway bed.  Just as quickly as I caught fish, I lost two magnets.

Thoughts:  The pools that form beneath a release tube or spillway are great places to fish.  While the release tubes usually have roads associated with them, the spillways often do not, making it more difficult to get to the pools.  The water that rushes down the ramp tends to gouge a large hole either beneath the gates or at the end of the reinforced spillway, and they generally hold large fish.  The Southwest has been in drought for much of the past two decades, only punctuated by rare wet years.  This is causing rivers, reservoirs, and spillways to dry up.  Even when there is no running water there are fish that seem able to survive.  Humans are generally not that lucky.  We need a constant refreshing of our water to survive.  Follow the science.  Change is coming and it starts with you.

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