Wednesday, November 11, 2009

Arivaca Improvement Information-for the 10 people who care.

For those in the southern part of the state, Arizona Game and Fish Biologist Jason Kline sheds some light on what is going on at the lake.

Just the facts, ma'am-
Arivaca is getting improvements, but not quite what you heard. The boat ramp is being reconstructed, not moved. It will have a new wider and straighter ramp and a floating dock with a light to make launching much easier. This will also get an ADA compliant walkway from the parking lot. If the permits from the Corps of Engineers allow, we will also put in a low water ramp as an extension of the new one. There is already a new restroom in place; it is not open yet, as we are waiting on a handicap parking spot and ADA sidewalk to be poured to it. The parking lot currently has drainage issues and is washing out the old ramp. To fix this, the lot will be re-graded and the bottom third of the lot will be paved. This will include a swale to direct water to drain to the lake, not the ramp. The road will NOT BE PAVED; this rumor has perpetuated for years, and is not true.

Arivaca has had gas motors allowed (10hp or less) since January of 2008; this was done to open a funding stream from the excise tax on gasoline for these and other improvements.

Fish Kill:
The lake will not have a fish kill just because it is low. I suppose this rumor is because the kill of 1999 occurred after it dropped to a very low level. What occurred was a chain on events that ended a kill:
1) The extremely low water level allowed terrestrial vegetation to grow, the lake refilled and the vegetation died and began to decompose-consuming oxygen in the lake
2) At the same time an algae bloom was occurring which normally puts oxygen back in the water, except at night or cloudy days when it consumes oxygen
3) We had a week of cloudy weather- so the bloom was consuming oxygen
4) The oxygen levels dropped to a lethal level and fish died.
Will all of this occur again? Possibly, but there is no way to predict these events. Arivaca is a hyper eutrophic lake, meaning it is super productive, so much so, that it can be to its own detriment. This is due to the high nutrient load in the water. It is not a bad thing, it is also the reason the fish grow so fast in Arivaca, it is just how the lake is.

Thanks for the information, Mr. Kline.



  1. Fished Arivaca yesterday witha couple of buddies, dredging the bottom with a Rio Deep 7 sinking line resulted in one 15" bass, a groove in the right middle finger from the incredible amount of tungsten in the aforementioned flyline.

    Beautiful day, started out chilly and very few boats - hard to launch with the current low water level. Fine with us: I was in my Fatboy floattube, they were in kayaks, so no problem launching for us. Less boats on the water to get in the way. Water was still relatively warm, so not total winter conditions just yet. For some reason, I enjoy twitching epoxy zonkers, crawdads, bunny leeches around in 15-25' of water. Not bad for the end of November.

    Guess the new boatramp will allow big boats, I don't the mind the way it is, but OK with the improvementsif they do happen.

    Crazy new recon tower out at the turnoff to the lake, Blackwater-style contractors hanging around at taxpayer expense - just another day on the border.

  2. Grate article. I am sure some moms in the bizymoms Arivaca community would love to read this. Please consider featuring this on their community site.


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