Area Stream & River Flow

Pecan Creek runoff filled Lake Nasworthy to the point two flood gates needed to be opened.  Both the North and South Concho River rose from recent rains.  The pictures are below:

The South Pool should be up as well.  I look forward to finding out how much.  Is is up enough for water to flow into the Equalization Channel without pumping?  That would be a blessing.

Update 5-25-14:  San Angelo Live said yes.

Will City Put Hold on North Pool Pumping?

San Angelo Live reported on Lake Nasworthy water releases as a result of locally heavy rains.  The city may wish to stop Twin Buttes North Pool pumping into Nasworthy given the water just goes downstream.  That said, North Pool pumps are at the greatest risk for flooding given their relatively low elevation.  It would be odd if the city had to keep the pumps running to keep them from being inundated.

 We'll see how this all plays out, but thank heaven for the rain.

Update 5-25-14:  The Standard Times reported "Sunday afternoon they were helping water utilities get the pumps out of the North Pool at Twin Buttes."

Setup for Runoff?

Tom Green County may be primed for runoff should more rains like last night's occur.   Here's the impact of Friday evenings storms and area creeks and rivers:

The South Concho at Christoval rose slightly then reverted to its prior low level flow.  Let's hope this evening's storms produce more runoff for area lakes.  It looks promising:

But I'm still praying.

Pumping's Measly Returns

The City of San Angelo utilized six pumps to move Twin Buttes water to Lake Nasworthy.  Three pumps take South Pool water into the Equalization Channel where it gravity flows into the North Pool.  A second set of three pumps sends North Pool water through the huge gates of the dam.

One third of the South Pool water is sent into Lake Nasworthy then released downstream.  Roughly another third is lost to seepage, thirsty vegetation and evaporation during travel.

A mere 19% of the pumped water is still in Lake Nasworthy.  This percentage came from the last two sets of lake water volume data published by San Angelo Live.  That means 15% is used for our daily water supply.

Let's hope the 19% remaining in Lake Nasworthy can be used later for the city's water needs and not have to be let downstream.

Without additional rains I expect the South Pool to be pumped out within three to four weeks. 

South Pool Down Over Three Feet

The South Pool at Twin Buttes is down nearly 3.5 feet as of Saturday afternoon.  Th elevation dropped from 1921.3 to less than 1918.  Three pumps are operating at the South Pool.  Last year the pump setup could move 75 acre feet a day  and that was a specification in this year's RFP for Twin Buttes pumping systems.

The system shall be capable of discharging approximately 75 acre-feet per day. 

A second set of three pumps is at the North Pool.  San Angelo Live shared the city's math on pumping:

The pumps at the South Pool are moving approximately 60 acre-feet of water per day and since Nasworthy loses some 25 acre-feet per day under normal conditions, the water from next door has to pay back the loss before it goes on to the credit side of the ledger.  According to data from the City’s water utility department, Lake Nasworthy has been gaining about 25 acre-feet of water per day since May 8th.

I would venture the South Pool pumps deliver 60 acre feet per day to the North Pool, losing 15 acre feet (of the 75) to seepage, thirsty vegetation and evaporation.   The North Pool takes that 60 and after evaporation/seepage Lake Nasworthy gets 50 acre feet, the 25 let downstream and 25 acre foot gain per day.

The North Pool is below the level the City pumped it to last Fall.  It seems they found a deeper channel for their three intake pipes.  The North Pool hasn't been suitable for windsurfing for quite some time.  The South Pool has maybe two weeks left where it is sailable.  With no rain Twin Buttes could soon be two small mud holes.  Pray for rain.

South Pool Down Two Feet

The City of San Angelo pumped two feet of water from the South Pool in the last ten days.  The goal is ten feet, so they're one fifth of the way.  Data from prior pumping efforts showed a 22 to 29% loss from the trip down the Equalization Channel.  Still, one would expect some impact in the North Pool's elevation from pumping.  It hasn't shown up yet. 

If anyone knows the reason why, I welcome your comments. 

City Pumps Over Half Foot from South Pool

In a few days the City of San Angelo removed nearly two-thirds of a foot of water from Twin Buttes South Pool.  The level dropped from 1921.25 elevation pre-pumping to 1920.60, a difference of .65 foot.

I paddleboarded the South Pool in light winds today.  The wind is predicted to increase tomorrow so I might be able to windsurf.  I need to sail while there's water.  It could be unsailable in a month's time.