DEVELOPMENT OF LOCAL DEVELOPMENT OF LOCAL DROUGHT TRIGGER DROUGHT TRIGGER

LEVELSLEVELSPREPARED BYPREPARED BY

THE HILL COUNTRY UNDERGROUND THE HILL COUNTRY UNDERGROUND WATER CONSERVATION DISTRICTWATER CONSERVATION DISTRICT

STATUTORY REQUIREMENTS FOR STATUTORY REQUIREMENTS FOR DROUGHT MANAGMENTDROUGHT MANAGMENT

TEXAS WATER CODE Sec.36.1071 Management Plan TEXAS WATER CODE Sec.36.1071 Management Plan (a) Following notice and hearing, the District shall, in coordination with surface (a) Following notice and hearing, the District shall, in coordination with surface

management water entities on a regional basis, develop a comprehensive management water entities on a regional basis, develop a comprehensive management plan which addresses the following goals, as applicable:management plan which addresses the following goals, as applicable:

(6) addressing drought conditions(6) addressing drought conditions

TEXAS WATER DEVELOPMENT BOARD RULESTEXAS WATER DEVELOPMENT BOARD RULES Chapter 356.5 Groundwater Management Chapter 356.5 Groundwater Management

Required Content of Management Plan Required Content of Management Plan (a) The executive administrator shall certify a management plan as (a) The executive administrator shall certify a management plan as

administratively complete if it uses a planning period of at least ten years administratively complete if it uses a planning period of at least ten years and contains the following:and contains the following:

(1) management goals ,as applicable(1) management goals ,as applicable (F) addressing drought conditions(F) addressing drought conditions

DROUGHT MANAGEMENT PLAN DROUGHT MANAGEMENT PLAN COMPONENTSCOMPONENTS

TRIGGER TRIGGER CONDITIONSCONDITIONS

DROUGHT DROUGHT MANAGEMENT MANAGEMENT STATEGIESSTATEGIES

TRIGGER CONDITIONSTRIGGER CONDITIONS

GROUNDWATER LEVEL DECLINESGROUNDWATER LEVEL DECLINES RAINFALLRAINFALL SPRING DISCHARGESPRING DISCHARGE STREAM AND RIVER FLOWSTREAM AND RIVER FLOW SOIL MOISTURESOIL MOISTURE PALMER DROUGHT INDEXPALMER DROUGHT INDEX PUMPAGE AND DISTRIBUTION PUMPAGE AND DISTRIBUTION

CAPACITIESCAPACITIES

PALMER DROUGHT INDEXPALMER DROUGHT INDEX

Developed by Wayne Palmer of the U.S. Developed by Wayne Palmer of the U.S. Department of Commerce Weather Bureau in Department of Commerce Weather Bureau in 19651965

Focuses on rainfall and soil moistureFocuses on rainfall and soil moisture Setup on a scale of -5 to 5. The greater the Setup on a scale of -5 to 5. The greater the

negative number the more intense the droughtnegative number the more intense the drought Prepared weekly by NOAHPrepared weekly by NOAH The index is calculated for broad areas which The index is calculated for broad areas which

may not be represented of local conditionsmay not be represented of local conditions

ELLENBURGER AQUIFER WATER LEVELS SEPTEMBER 1, 2004

DEVELOPMENT OF A LOCAL DEVELOPMENT OF A LOCAL DROUGHT INDEX BASED ON:DROUGHT INDEX BASED ON:

Palmer Hydrological Drought IndexPalmer Hydrological Drought Index Aquifer Water Levels from two City of Aquifer Water Levels from two City of

Fredericksburg Ellenburger Monitor WellsFredericksburg Ellenburger Monitor Wells Stream Flow from the Pedernales River at Stream Flow from the Pedernales River at

the LCRA gauge site south of the LCRA gauge site south of FredericksburgFredericksburg

Rainfall for the previous 10 month total as Rainfall for the previous 10 month total as recorded at Lady Bird Johnson Municipal recorded at Lady Bird Johnson Municipal ParkPark

LOCAL DROUGHT INDEXDATA BASE

Date Julian_Yr

Hahn Test Well W.L.

Knuath #1 W.L.

Stream Discharge

Previous10 month Rainfall PHDI

PRED PHDI PDSI

PRED PSDI

1/1/00 36526.00 1514.75 1502.47 9.60 17.89 -3.70 -3.08 -3.70 -2.711/2/00 36527.00 1515.00 1502.64 9.90 17.89 -3.70 -3.07 -3.70 -2.721/3/00 36528.00 1515.25 1502.81 9.60 17.89 -3.70 -3.05 -3.70 -2.731/4/00 36529.00 1515.50 1502.98 8.90 17.89 -3.70 -3.04 -3.70 -2.731/5/00 36530.00 1515.75 1503.15 8.30 17.89 -3.70 -3.02 -3.70 -2.741/6/00 36531.00 1516.00 1503.32 8.20 17.89 -3.70 -3.01 -3.70 -2.751/7/00 36532.00 1516.25 1503.49 9.80 17.89 -3.70 -2.99 -3.70 -2.751/8/00 36533.00 1516.50 1503.66 13.00 17.89 -3.70 -2.98 -3.70 -2.761/9/00 36534.00 1516.75 1503.83 13.00 17.89 -3.70 -2.96 -3.70 -2.771/10/00 36535.00 1517.00 1504.00 13.00 17.89 -3.70 -2.95 -3.70 -2.771/11/00 36536.00 1517.25 1504.17 12.00 17.89 -3.70 -2.93 -3.70 -2.781/12/00 36537.00 1517.50 1504.34 10.00 17.89 -3.70 -2.92 -3.70 -2.791/13/00 36538.00 1517.75 1504.51 9.90 17.89 -3.70 -2.90 -3.70 -2.791/14/00 36539.00 1518.00 1504.68 10.00 17.89 -3.70 -2.89 -3.70 -2.801/15/00 36540.00 1518.25 1504.85 10.00 17.89 -3.70 -2.87 -3.70 -2.811/16/00 36541.00 1518.50 1505.02 10.00 17.89 -3.70 -2.86 -3.70 -2.811/17/00 36542.00 1518.75 1505.19 10.00 17.89 -3.70 -2.84 -3.70 -2.821/18/00 36543.00 1519.00 1505.36 10.00 17.89 -3.70 -2.83 -3.70 -2.831/19/00 36544.00 1519.25 1505.53 10.00 17.89 -3.70 -2.81 -3.70 -2.831/20/00 36545.00 1519.50 1505.70 9.90 17.89 -3.70 -2.80 -3.70 -2.841/21/00 36546.00 1519.75 1505.87 9.60 17.89 -3.70 -2.78 -3.70 -2.851/22/00 36547.00 1520.00 1506.04 9.60 17.89 -3.70 -2.77 -3.70 -2.861/23/00 36548.00 1520.25 1506.21 9.60 17.89 -3.70 -2.75 -3.70 -2.861/24/00 36549.00 1520.50 1506.38 8.40 17.89 -3.70 -2.74 -3.70 -2.87

LOCAL DROUGHT INDEX REGRESSION REPORT

Robust Multiple Regression Using Huber's Method (C=1.345) Page/Date/Time 1 9/8/2004 2:29:45 PM Database C:\NCSS97\DATA\LOCALDRINDEX.S0 Dependent PHDI Run Summary Section Parameter Value Parameter Value Dependent Variable PHDI Rows Processed 1482 Number Ind. Variables 4 Rows Filtered Out 0 Weight Variable None Rows with X's Missing 13 R2 0.6446 Rows with Weight Missing 0 Adj R2 0.6436 Rows with Y Missing 0 Coefficient of Variation -1.8328 Rows Used in Estimation 1469 Mean Square Error 1.660993 Sum of Weights 1429.782 Square Root of MSE 1.288795 Completion Status Normal Completion Ave Abs Pct Error 88.348 Descriptive Statistics Section Standard Variable Count Mean Deviation Minimum Maximum Hahn_T_W_ 1469 1524.45 8.386988 1499 1537.714 Knauth_1 1469 1497.297 9.789451 1469 1532.5 Stream_Discharge 1469 76.64099 502.8919 0 14542 X10mth_Rain 1469 25.32108 6.700631 10.59 39.95 PHDI 1469 -0.7031668 2.158753 -5.06 2.99 Regression Equation Section Regression Standard T-Value Reject Power Independent Coefficient Error to test Prob H0 at of Test Variable b(i) Sb(i) H0:B(i)=0 Level 5%? at 5% Intercept -141.4800 7.9922 -17.702 0.0000 Yes 1.0000 Hahn_T_W_ 0.1033 0.0048 21.593 0.0000 Yes 1.0000 Knauth_1 -0.0141 0.0036 -3.937 0.0001 Yes 0.9760 Stream_Discharge 0.0004 0.0001 6.255 0.0000 Yes 1.0000 X10mth_Rain 0.1699 0.0059 29.015 0.0000 Yes 1.0000 Estimated Model -141.479952413932+ .10334830074037*Hahn_T_W_-1.40964017972087E-02*Knauth_1+ 4.18674177533084E-04*Stream_Discharge+ .169893670253439*X10mth_Rain

LOCAL DROUGHT INDEX REGRESSION REPORT

Robust Multiple Regression Using Huber's Method (C=1.345) Page/Date/Time 4 9/16/2004 1:33:07 PM Database C:\NCSS97\DATA\LOCALDRINDEX.S0 Dependent PHDI Robust Residuals and Weights Absolute Actual Predicted Percent Robust Row PHDI PHDI Residual Error Weight 1 -3.700 -3.198 -0.502 13.570 1.0000 2 -3.700 -3.174 -0.526 14.229 1.0000 3 -3.700 -3.149 -0.551 14.881 1.0000 4 -3.700 -3.125 -0.575 15.529 1.0000 5 -3.700 -3.101 -0.599 16.178 1.0000 6 -3.700 -3.077 -0.623 16.833 1.0000 7 -3.700 -3.052 -0.648 17.507 1.0000 8 -3.700 -3.027 -0.673 18.199 1.0000 9 -3.700 -3.002 -0.698 18.855 1.0000 10 -3.700 -2.978 -0.722 19.511 1.0000 11 -3.700 -2.954 -0.746 20.155 1.0000 12 -3.700 -2.931 -0.769 20.788 1.0000 13 -3.700 -2.907 -0.793 21.443 1.0000 14 -3.700 -2.882 -0.818 22.100 1.0000 15 -3.700 -2.858 -0.842 22.756 1.0000 16 -3.700 -2.834 -0.866 23.412 1.0000 17 -3.700 -2.809 -0.891 24.068 1.0000 18 -3.700 -2.785 -0.915 24.723 1.0000 19 -3.700 -2.761 -0.939 25.379 1.0000 20 -3.700 -2.737 -0.963 26.034 1.0000 21 -3.700 -2.713 -0.987 26.686 1.0000 22 -3.700 -2.688 -1.012 27.342 1.0000 23 -3.700 -2.664 -1.036 27.998 1.0000 24 -3.700 -2.640 -1.060 28.640 1.0000 25 -3.700 -2.616 -1.084 29.294 1.0000 26 -3.700 -2.592 -1.108 29.946 1.0000 27 -3.700 -2.567 -1.133 30.621 1.0000 28 -3.700 -2.543 -1.157 31.282 1.0000 29 -3.700 -2.518 -1.182 31.949 1.0000 30 -3.700 -2.494 -1.206 32.605 1.0000 31 -3.700 -2.470 -1.230 33.249 1.0000 32 -3.860 -2.853 -1.007 26.089 1.0000 33 -3.860 -2.827 -1.033 26.762 1.0000 34 -3.860 -2.801 -1.059 27.428 1.0000 35 -3.860 -2.800 -1.060 27.471 1.0000 36 -3.860 -2.798 -1.062 27.502 1.0000 37 -3.860 -2.797 -1.063 27.534 1.0000 38 -3.860 -2.796 -1.064 27.566 1.0000 39 -3.860 -2.793 -1.067 27.630 1.0000 40 -3.860 -2.793 -1.067 27.651 1.0000 41 -3.860 -2.791 -1.069 27.690 1.0000 42 -3.860 -2.790 -1.070 27.730 1.0000 43 -3.860 -2.788 -1.072 27.769 1.0000 44 -3.860 -2.787 -1.073 27.810 1.0000

COMPARISON OF THE PHDI AND THE CALCULATED LOCAL DROUGHT INDEX

8/28/99 10/1 /00 11/5 /01 12/10/02 1/14/04 2/17/05D ATE

-6

-4

-2

0

2

4

6

PH

DI

-6

-4

-2

0

2

4

6

Pre

dic

ted

PH

DI

PH DI vs PR ED IC TED PH D I

COMPARISON OF THE LOCAL DROUGHT INDEX AND THE HAHN TEST WELL #1 WATER LEVELS

8/28/99 10/1 /00 11/5 /01 12/10/02 1/14/04 2/17/05D a te

-6

-4

-2

0

2

4

6

Lo

cal D

roug

ht I

nd

ex

1490

1500

1510

1520

1530

1540

Ha

hn

Te

st W

ell

#1

Wa

ter

Le

vels

COMPARISION OF THE LOCAL DROUGHT INDEX AND THE KNAUTH# 1 WATER LEVELS

8/28/99 10/1 /00 11/5 /01 12/10/02 1/14/04 2/17/05

-6

-4

-2

0

2

4

6

Loca

l Dro

ught I

ndex

1460

1470

1480

1490

1500

1510

1520

Knauth

# 1

Wate

r le

vels

COMPARISON OF THE LOCAL DROUGHT INDEX TO THE PEDERNALES RIVER FLOW

8/28/99 10/1 /00 11/5/01 12/10/02 1/14/04 2/17/05

-6

-4

-2

0

2

4

6

Lo

cal D

rou

gh

t In

de

x

0

100

200

300

Pe

de

rna

les

Riv

er

Flo

w (

cfs)

COMPARISON OF THE LOCAL DROUGHT INDEX AND THE PREVIOUS 10 MONTH RAINFALL TOTALS

8/28/99 10/1 /00 11/5 /01 12/10/02 1/14/04 2/17/05D a te

-6

-4

-2

0

2

4

6

Loca

l Dro

ught I

ndex

10

20

30

40

Pre

vious

10 M

onth

Rain

fall

Tota

ls