| Name: |
Maverick
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| Subject: |
APCo Drought based Variance
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Date:
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1/30/2008 6:27:49 PM
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Just looked back at APCo drought variance graphs from their letter of October 23, 2007 to FERC and the graphs showed the following
- WITHOUT the drought based variance APCo's graph showed the lake level today to be 480. (Attachment 2)
- WITH the drought based variance the graph shows 484 as of today (Attachment 3)
Boy APCo's assumptions in terms of rainfall must have been way off or they are releasing more water downstream then the minimum. aso fo today we are at 476.6 or 7.6 feet below their estimates.
Do we have any engineers in the crowd who would like to take a swag at calcuating what the lake level should be assuming the actual rainfall since Novermber 20th and the minmum downstream releases as granted by FERC back on Nov 20th? That is, just a little reasonableness test to keep everyone honest here.
URL: APCO Letter and Graphs
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| Name: |
Maverick
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| Subject: |
Scheduled Releases
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Date:
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1/30/2008 7:05:50 PM
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After my above post I was curious as to what the past releases had been and the scheduled releases are so went to APCo's website. And agree with post below as the APCo website does show there are no releases scheduled from Martin for the next 3 days and I believe if I am not mistaken there have not been any releases in the past 5 days or so as well.
So guess the answer is -- WE NEED RAIN !!!!
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| Name: |
Trent
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| Subject: |
Scheduled Releases
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Date:
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1/30/2008 7:24:27 PM
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Have you seen this site??
http://water.sam.usace.army.mil/actframe.htm
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| Name: |
Osms
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| Subject: |
Maverick the Wizard
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Date:
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1/30/2008 8:00:52 PM
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Now that Maverick has figured out that we need rain, I have forwarded him two Excel spreadsheets that show inflow and outflow from January 1, 2007 til January 17, 2008. He will load those onto the HOBO website--and he will tell you the location to find them. Compare the inflow and outflow for Lake Martin in January 2007 and January 2008. You will see we are receiving very little inflow and are allowing almost no outflow. Remember January 2007, was a fairly dry month. Numbers are in cfs.--cubic feet per second.
As Maverick discovered--all on his own--we need rain.
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| Name: |
Maverick
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| Subject: |
OSMS With Regards to Your Post
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Date:
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1/30/2008 9:15:45 PM
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Instead of posting such derogatory comments, why not post some real information folks can sink their teeth into and appreciate like as follows. (Now that I have the Excel spreadsheets you sent me from the Corps. )
Base don my callcuation of the historical data to raise Lake Martin 1 foot we need a net inflow of approx 17,000 - cfs.--cubic feet per second
Since the drought variance went into effect on November 22nd per the Corps Excel spreadsheets Martin's inflows and outflows have been as follows through Jan 17, 2008 (Jan 17th is the last data on the spreadsheet):
Inflows - 35,164
Outlfows - 13,874 (avg of 274.75 per day)
Net Inflows - 21,290 cfs.--cubic feet per second
So based on my calucation of needing approx 17,000 CFS to raise the lake 1 foot and based on 21,290 cfs of net inflow the lake should have rinsen by approx 1.25 feet since 11/22. And the lake has risen from 474.6 on 11/22 to 475.9 as of 1/17 or 1.3 feet.
To also further note the outlfows have been 13,874 cfs over a 56 day period or approx 247.75 cfs relased per day on average, which I if am not mistaken is below what was agreed to with the Corps by APCo.
Hope this info helps to shed some light on the overall picture as to why the lake is not rising faster than we would all like.
As we have all said in the past PRAY FOR RAIN !!!!
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| Name: |
Maverick
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| Subject: |
Corps - Excel Spreadsheets
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Date:
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1/30/2008 9:31:39 PM
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If you are interested in viewing the Corp Inflow and Discharge Excel Spreadsheets for 2007 and 2008 and doing your own calculations copy and paste the foll wing links into you browser's address.
YOU WILL NEED EXCEL ON YOUR COMPUTER TO OPEN THESE FILES
2007 Data: http://www.lakemartin.org/NewsUpdates/DailyInflowDischarge_2007.xls
2008 Data:
http://www.lakemartin.org/NewsUpdates/DailyInflowDischarge_2008.xls
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| Name: |
roswellric
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| Subject: |
Maverick the Wizard
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Date:
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1/30/2008 9:44:10 PM
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Have you looked at Wedowee's level?
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| Name: |
Maverick
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| Subject: |
No to Wedowee
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Date:
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1/30/2008 9:53:14 PM
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I will try to calc Wedowee tomorrow night or later tonight.
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| Name: |
Osms
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| Subject: |
But wait.......
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Date:
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1/30/2008 9:54:16 PM
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you forgot to figure in the coefficient of the absorption/hour for ....DIRT.
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| Name: |
Maverick
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| Subject: |
But wait.......
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Date:
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1/30/2008 9:58:55 PM
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And the total cubic footage based on the surface level of water today as compared to the surface level of water at lower pool.
But never said I was an engineer, just a WIZARD !!!!!
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| Name: |
Osms
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| Subject: |
But wait.......
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Date:
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1/30/2008 10:16:29 PM
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I was the one who said you were a wizard--don't let it go to your head!!
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| Name: |
Maverick
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| Subject: |
Roswell - Wedowee
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Date:
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1/30/2008 10:30:31 PM
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Based on some quick calcs: (Same info as Martin so folks can compare)
Based on my calculation of the historical data to raise Wedowee 1 foot they need a net inflow of approx 4,000 - cfs.--cubic feet per second (or 325% less inflow than Martin requires, based on acreage of both lakes this is reasonable)
Since the drought variance went into effect on November 22nd per the Corps Excel spreadsheets Wedowee's inflows and outflows have been as follows through Jan 17, 2008 (Jan 17th is the last data on the spreadsheet):
Inflows - 25,796
Outlfows - 6,780 (avg of 121.07 per day)
Net Inflows - 19,016 cfs.--cubic feet per second
So based on my calculation of needing approx 4,000 CFS to raise Wedowee 1 foot and based on 19,016 cfs of net inflow the lake should have rinsen by approx 4.75 feet since 11/22. And Wedowee has risen from 780.2 on 11/22 to 785.3 as of 1/17 or 1.3 feet.
Hope this info helps to shed some light on the overall picture as to why Wedowee is up 5 feet and Martin is not.
Disclaimer: These are simple calculations and do not take into account the numerous variables which would be required to calc the exact numbers. So this data should not be relied on in any form or fashion - LOL.
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| Name: |
Maverick
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| Subject: |
Roswell - Wedowee (Typo)
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Date:
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1/30/2008 10:33:28 PM
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Ths sentence should read Wedowee has risen 5.1 feet not 1.3 feet. Sorry.
And Wedowee has risen from 780.2 on 11/22 to 785.3 as of 1/17 or 1.3 feet.
Sorry
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| Name: |
Feb
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| Subject: |
Maverick the Wizard
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Date:
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1/31/2008 11:06:26 AM
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Mav, if you are a wizzard? Then just fill up the blasted lake. All these funny numbers are making my head hurt. I just want my body washed.
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I have too much "time off"? LOL
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| Name: |
Maverick
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| Subject: |
Nope
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Date:
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1/31/2008 12:33:24 PM
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Have always been curious as to what the numbers were to fill the lake 1 foot and since I had the data I love a challenge. So I figured I would try to calc some meaningful numbers to put everything into perspective.
LOL.
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| Name: |
8hcap
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| Subject: |
Roswell - Wedowee
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Date:
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1/31/2008 12:52:37 PM
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Mav,
Doesn't this tell us the only inflows we receive are the 121 cfs per second released from Harris plus local rainfall and drainage below the Harris Dam? As a result, we receive little if any benefit from the Georgia watershed.
Could APCO still be interested in selling its 10,000 acres to the Reynolds Plantation group?
8
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| Name: |
Maverick
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| Subject: |
8
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Date:
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1/31/2008 1:33:18 PM
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8 - Yes you are correct as Harris would receive any benefits from the upstream watershed in GA.
With repsect to Reynolds Plantation not sure.
But what I do know is that at one time GA wanted to place a dam above Harris and this idea was tabled after much fighting as GA would then be able to control the upstream flows above Harris.
Do not know if this answers your question or not.
Also Martin has a very small watershed as compared to other river basins. For example, I was told by the Director of Lake Alatoona's Water Authority that one inch of rain over their basin will raise Lake Alatoona by approx 1 foot, as their watershed is HUGE. In contrast I would supect for Martin we would need about 4 to 5 times this amount of rain to raise Martin1 foot, assuming not outflows.
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| Name: |
Lakeman
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| Subject: |
But wait.......
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Date:
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2/1/2008 9:09:50 AM
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Also don't forget to allow for the changing moon phases.
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| Name: |
MartiniMan
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| Subject: |
8
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Date:
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2/1/2008 1:49:43 PM
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Maverick: Lake Martin size is 44,000 acres with a watershed of 3,000 square miles or 14.76 acres per sq mile of watershed. Alatoona size is 12,000 acres with a watershed of 1,100 sq miles or 10.91 acres per sq mile of watershed. So Allatoona actually has a little larger watershed per acre than Martin, but not significantly larger. Its even more dramatic with Lanier. Lanier is 38,000 acres in size with a watershed of 1,040 sq miles (essentially the same as Allatoona) or 36.54 acres per sq mile of watershed. Combine that small a watershed with the lake of that size and throw in the incredible water demands of the city of Atlanta and the downstream flow requirements and you can see why Lanier is so volatile and sensitive to rainfall.
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| Name: |
LifeTime Laker
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| Subject: |
APCo Drought based Variance
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Date:
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2/2/2008 11:42:47 AM
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I have read this thread with interest, as I too have wondered for years about the same question. I don't even know if APCO has a 'magic formula' . There are way to many variables in the equation. One that I noticed you didn't consider is outtakes of all the local water systems that pull from the lake, another is evaporation. Granted both may be neglible, but must be considered. And evaporation increases exponintially as the tempurature rises, and decreases as humudity increases. Both can even vary greatly within any 24 hour period.
Entertaining read anyway and I am sure your figures are as accurate as they can be with the data used.
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