Lack of Runoff for Twin Buttes

I walked the banks of the Middle Concho yesterday, hoping to hear the river roar. Over the weekend heavy rains near Barnhart washed away a pickup truck. Fortunately, the driver escaped safely from the raging river, suddenly a 150 to 200 feet wide torrent. 

From the data above, none of that runoff made the North Pool at Twin Buttes, which is fed by the Middle Concho.  Or, if it did, the City has been letting it (and more) flow through the gate at Twin Buttes.

Pressure Grows on Twin Buttes

The Standard Times reported:

The drinking water allowance allocated to the city of San Angelo from the O.H. Ivie Reservoir was cut by 30 percent this month.

San Angelo will need to make up the difference by drawing more from local reservoirs.

That means Twin Buttes.

The San Angelo City Council voted this week to take steps toward pumping water out of the South Pool of the Twin Buttes reservoir and putting it into use since water becomes trapped in the South Pool after it is drawn down past a certain elevation, thereby leaving about a month's worth of water out of reach.

The City plans to pump South Pool water in June, a time of high heat and evaporation.

"Since we'll be relying more on our local sources, to gravity feed down to the water plant, we'll have to start utilizing everything we can from Twin Buttes," said Will Wilde, the city's director of water utilities.

It will gravity feed the water, meaning dry soil and water wicking plants will have their chance to violate the city's assumption:

No water will be lost in the transfer process from the south to north pool..

The City can build a pipeline to Hickory, but can't get South Pool water to the treatment plant without loss?  Something strange is going on.

Councilman Paul Alexander says not to worry about the South Pool:

One medium rain, and that lake (South Pool) will fill up overnight. It takes about 90 days to drain that pool, so we are way behind in schedule. We should be pumping starting April 1st at the latest.

How did last night's rain impact Twin Buttes?  It looked like a medium rain across the Twin Buttes watershed on radar.  This morning's flow looked like:

As for the city's projections on less evaporation, they assume water can be shifted from one pool to the other instantaneously.  They show the South Pool's 520 surface area acres added to the North Pool's 882, bringing the North Pool's surface area to 1093 acres, then show a year's worth of savings.

In reality, that process takes "about 90 days" and will occur during our high evaporation months.  As a result, evaporation savings will be much less than the projected 1622 acre feet.

With our Ivie drinking water down and O.C. Fisher barren, Twin Buttes is it.  .

Update 4-9-12:  Twin Buttes elevation is reported unchanged by the Bureau of Reclamation.  Hopefully, the runoff is upstream, working its way down.

Raise North Pool Five Feet: Less Than Amount Lost to Annual Evaporation

Councilman Paul Alexander shared the city's study on pumping the total volume of the South Pool into the North Pool at Twin Buttes.  It turns out the North Pool will rise by 5.15 feet, while annual evaporation is 5.25 feet, the vast majority of which occurs during the summer. If the whole amount of the transfer stands to be evaporated over a year's time, what are the savings? 

April 2, 2012 Evaporation savings by moving water from South Pool to North Pool at Twin Buttes

Assumptions:

1) current levels of both pools as of 4/2/2012,

2) no loss of water in the transfer from the south to north pools.

Twin Buttes Reservoir

ELEVATION(FT) AREA(ACRES) VOLUME(ACRE-FT)

North Pool 1890.65’ 882 8,170

South Pool 1925.78’ 520 5,028

Total 1,402 13,198

Projected with observed south pool transferred to north pool

North Pool 1895.8’ 1,093 13,198

Projected change in water surface area (1402-1093) = 309 acres

Approximate annual average evaporation is 63 inches/year=5.25 feet

Change in water evaporated: 309 Acre Feet * 5,25 feet = 1622 acre feet per year.

These numbers are approximate and apply with the assumptions made.

The reality is the dry 211 acres in the North Pool will absorb some amount of South Pool water.  How much thirsty vegetation grew on those 211 acres?  This came from a Twin Buttes Brush Control Study from April 2010:

One acre of saltcedar on the Pecos River of Texas was estimated to use 5-7 acre-ft. of water every year (Hart 2003). The longer saltcedar occupies an area, the drier the area becomes. Saltcedar currently dominates 1,092 acres in the project area (Twin Buttes).

Councilman Alexander believes a few modest rains will rapidly refill the South Pool.  We've had modest rains since October and the South Pool is up about two feet.  What happens when the South Pool is completely drained, as in the city's assumption?  Will the spring fed South Concho keep its flow?  How much thirsty vegetation will grow on the South Pool lake bed?  How will that impact a "modest rain's" ability to refill the South Pool.

The City frequently offers crude analysis to push their desired strategies.  This got play in August last year, then became embedded in a consent agenda.  The public, especially users of the South Pool, deserve better.

I understand the city needs water.  It should pump what it needs to in the most efficient and effective way possible.  If it can build a pipeline to pump Hickory water, it should be able to do the same from the South Pool.  Rather than assume no loss, it should guarantee such.

This issue arose in 2004.   Why didn't San Angelo's Water Czar make recommendations to utilize South Concho River water effectively in a time of drought?  What impact did agricultural commitments have on such plans?

Much of the stored water is used to irrigate 10,000 acres of crop and rangeland (Reclamation 1994).

How did the Water Czar's "hobby farm," which draws water for irrigation from the South Pool, enter into consideration?  The public won't know.  That topic is off limits.

Update 4-7-12:  Councilman Alexander's medium rain may be in the offing.

City to Pump Water from South Pool

San Angelo City Council agenda for April 3rd shows the following item:

Consideration of selecting Gajeske, Inc. for RFP WU-02-12 Lake Pumping System to transfer water from the South Pool of Twin Buttes Reservoir to the North Pool and authorizing the Interim City Manager or his designee to execute any necessary related documents.

I wrote about the City's RFP for pumping dead pools in late January. The South Pool increased several feet, while the North Pool withered.

This isn't the first time the subject of pumping from the South Pool arose.  Harken back to May 2004:

CONSIDERATION OF MATTERS DISCUSSED IN EXECUTIVE/CLOSED SESSION, SPECIFICALLY TO ADVISE ATTORNEY TIM BROWN OF QUESTIONS RAISED BY TCEQ AND TO BEGIN THE PREPARATION OF A RESPONSE

Council discussed whether to apprise Attorney Tim Brown of questions raised by the TCEQ regarding the City's rights to pump water from the south pool over Twin Buttes Dam and to divert water by City property leaseholders along the South Concho River.

Motion, to advise Attorney Tim Brown of questions raised by TCEQ and request that he begin the preparation of a response, was made by Councilmember Rainey and seconded by Mayor Lown. Motion carried unanimously.

Last summer the issue rose again

DISCUSSION AND CONSIDERATION OF PUMPING WATER FROM THE SOUTH POOL OF THE TWIN BUTTES RESERVOIR
City Manager Harold Dominguez and Water Utilities Director Will Wilde presented background information.  A copy of the lake level chart document is part of the permanent supplement file.  Discussion was held on the creating a plan to pump the water in the future from the pools and explore recreational uses for the area.

Note the South Concho River, which feeds the South Pool, has the most consistent flow of any river in the Concho Valley.  What recreational uses did Council have in mind for the South Pool?

Will the City of San Angelo deplete our most drought resistant windsurfing lake and turn it into a mudders' paradise?  Time will tell.

One thing's for sure, access will be limited, per Council actions in January 2012: 

Motion, to authorize staff to move forward with controlled vehicular access to the four designated access points, as presented by staff: 1) access to south shore of the north pool of Twin Buttes, 2) access to the west side of the south pool of Twin Buttes, 3) access to the east side of the south pool of Twin Buttes, and 4) access to the area north of Hwy 67 related to public safety issues and access to public areas at the Twin Buttes Reservoir, was made by Councilmember Hirschfeld and seconded by Councilmember Alexander. Motion carried unanimously.

Councilmember Alexander suggested staff consider opportunities to generate revenue, specifically user fees, and reinvestment strategies.

Twin Buttes stakeholders input was sought on February 16, long after the Council train had left the station.  I'm concerned given Twin Buttes stakeholders placed RV hookups low on the priority list, yet such amenities were high in the consultant's report.

User fees, this is starting to feel like a setup.  Will I be charged per board, maybe per sail? 

Twin Buttes: Tale of Two Pools

The South Pool recently sent water into the Equalization Channel at Twin Buttes.  I wonder if the trickle reached the badly depleted North Pool (pictured above).

While 2012 rains greened the ground, they're yet to add substantial runoff to area lakes.

 
Twin Buttes is the blue line in the chart above.  It's back in the hurtin' zone, with most of the water in the South Pool and away from the dam gates.  Pray for a gully washer in the Twin Buttes watershed..

City Hosts Visioning Session for Twin Buttes

Roughly forty people turned out for a City hosted Visioning Session on Twin Buttes Reservoir Thursday evening.  Representatives from the outdoor community included fishermen, hunters, windsurfers, kayakers, off-road riders (ATV and full sized vehicles), runners, trail cyclists, disc golfers, archers and more. 

Lauren Shrum from Texas Outdoors Consulting ably facilitated the session.  Everyone had a chance to contribute their ideas to a master list, which the group later prioritized.  Some of the ideas were in direct contrast to one another.  Examples include:

• keep everything wide open vs. restricting access
• keep the property primitive vs. developing nice camping slots with hookups.  

The group didn't eliminate conflicting ideas, but everyone got to vote their priorities. 

I used my eight votes on:

1) Vehicle access to large areas of the lake shore (both North and South Pools for windsurfing)

2) Regular trash cleanup in high use areas

3) Access to well maintained public restrooms

4) Visible and regular police presence

The Visioning Workshop regarded "the future of the Twin Buttes Recreation Area as part of the master planning process." It remains to be seen if this is a ground up effort or top down directive, like the recent installation of pipe railing.  Never the less, I'm grateful to Carl White, Anthony Wilson and Lauren Shrum for the chance to be heard. Many thanks to Alvin, Joan and Kristin for adding their voice on behalf of windsurfers.  The meeting was worth the time.

Update 2-24-12:  Bill Cullins authored a piece in the Standard Times on this issue.  It's worth the read.

Upcoming Twin Buttes Visioning Workshop

The City of San Angelo will hold a visioning workshop for Twin Buttes Reservoir in the near future.  The event is invitation only and will be facilitated by Texas Outdoor Consulting.  City leaders identified stakeholders to represent specific interest groups.  I've been designated the contact person for the windsurfing community and asked to bring four windsurfers to the session.   

I made a few calls, sent some e-mails.  Alvin said he could go.  I hope to hear from Medwin, Bill L. and Bill C. 

If any new windsurfers or ancient mariners want to go (James R., Lorenzo L, Rick E., Jimmy, George G., Leroy or Steve S.), please contact me at PEUReport@gmail.com.  I'm excited our voice will be heard.

P.S.  The South Pool was up when I sailed in early January.  I'd guess it was at least a foot to foot and a half higher.  The water was a chilly 52-54 degreees.