Appendix D

Monthly Report with Storage Projection Plots

Orange River System: Annual Operating Analysis May 2008/2009

May 2008 analysis

Three yearly reservoir projections for all major dams in system

Note : Historical reservoir performances were updated to include actual dam storages up to 31 January 2009.

IMPORTANT NOTES ON OPERATING RULES (2008/2009) : Based on the final agreed Scenario for the 2008/09 operating analysis.

(a)

(b)

( c )

(d)

(e)

(f)

Table A: Scheduled water releases from May 2008 to April 2009 from Gariep & Vanderkloof Dams, lag included.

Month

(million m3) (m3/s) (million m3) (m3/s)

08-May 230.7 86.131 77.3 28.855

08-Jun 158.8 61.256 73.2 28.227

08-Jul 153.1 57.173 88.8 33.17

08-Aug 186.1 69.499 120.8 45.093

08-Sep 203.1 78.348 177.9 68.618

08-Oct 180.9 67.54 239.2 89.321

08-Nov 138.7 53.515 263.9 101.822

08-Dec 122.1 45.591 294.9 110.117

09-Jan 124.2 46.387 277.5 103.608

09-Feb 165.4 67.775 192.6 78.891

09-Mar 225.8 84.309 160.6 59.976

09-Apr 249.1 96.085 116.9 45.096

Annual 2138.1 2083.6

Table B: Storage control curves to be used in 2008/2009 year

Description Level in m.a.s.l

Oct Nov Dec Jan Feb Mar Apr May Jun Jul Aug Sep

GariepFull supply level 1258.69 1258.69 1258.69 1258.69 1258.69 1258.69 1258.69 1258.69 1258.69 1258.69 1258.69 1258.69

20% SCC 1257.98 1258.06 1258.16 1258.32 1258.48 1258.60 1258.63 1258.55 1258.42 1258.27 1258.12 1257.99

m below FSL 0.71 0.63 0.53 0.37 0.21 0.09 0.06 0.14 0.27 0.42 0.57 0.70

% of gross storage 95.69 96.16 96.80 97.75 98.74 99.48 99.62 99.17 98.38 97.45 96.53 95.74

VanderkloofFull supply level 1170.50 1170.50 1170.50 1170.50 1170.50 1170.50 1170.50 1170.50 1170.50 1170.50 1170.50 1170.50

20% SCC 1170.30 1170.10 1169.91 1169.74 1169.74 1169.78 1169.87 1169.99 1170.16 1170.29 1170.40 1170.40

m below FSL 0.20 0.40 0.59 0.76 0.76 0.72 0.63 0.51 0.34 0.21 0.10 0.10

% of gross storage 99.17 98.37 97.60 96.90 96.89 97.07 97.42 97.90 98.62 99.13 99.58 99.60

The Storage Control Curves (SCC) to be used for Gariep and Vanderkloof dams for the 2008/2009 year are given in Table B

Gariep Dam Vanderkloof Dam

(3) Increasing the discretionary allocation to DWAF Regional office from 70 to 100 million m3.

The discretionary allocation to the DWAF Regional office for the 2008/09 year is 100 million m3. This volume forms part of the overall operating

requirements of the Orange River System. This volume can also be utilized by Eskom for hydro-power generation purposes. The volume and time of

the releases are however determined by the DWAF regional offices.

The discretionary additional allocation to Eskom for the 2008/09 year is 71 million m3. This volume can be utilized by Eskom any time during the year

and can be released both from Gariep and Vanderkloof dams.

The release volumes from Gariep and Vanderkloof dams are given in Table A below and exclude the discretionary allocations to DWAF and Eskom.

These volumes are to be released from Vanderkloof and Gariep dams to satisfy the downstream requirement and to be simultaneously utilized for

hydro-power generation.

If Vanderkloof Dam is currently above the new storage control curve, the water should not be released from Vanderkloof as this high water level was

caused by to high releases from Gariep Dam and not by natural causes (rainfall runoff)

Releases from Gariep should be reduced in order to prevent Vanderkloof Dam from raising above its SCC level. Only when Gariep Dam is above its

SCC and high releases from Gariep has therefore been made, should water levels in Vanderkloof Dam be allowed to rise above its SCC. Water from

Vanderkloof Dam can then be released through the turbines at maximum capacity in order reduce/prevent spilling from the dam. Exceeding the SCC

in Vanderkloof Dam will in particular be critical in the first 5 months and great care should be taken in this regard.

For actual transfers and releases refer to "Actual Flows" sheet

It is important to note that the simulated reservoir trajectories were based on the June 2008 analysis which

was undertaken subsequent to the Eskom Meeting held on 8 June 2007, as based on the final agreed scenario.

This scenario included a 20% storage control curve and resulted in a 71 million m3 discretionary allocation to Eskom.

Updates with respect to the 2007/08 analysis include the following:

(1) Update of demands and demand projections where information was available. The main changes included: .....-

(2) Inclusion of Storage Control Curves.

November 2008 analysis

Introduction:

The TOR for this study requested that a second decision date must be included as part of the operating rule. The second decision date was agreed

to be 1 November each year. The main decision date will remain to be on the 1st of May each year, followed by a secondary decision date on the1

st of

November. This means that the annual discretionary allocation to Eskom if any, as given in May, will preferably not be reduced as result of the

November analysis. Mainly under conditions where curtailments were imposed in May, will the November analysis be used to determine if the

curtailments can be reduced or lifted. Depending on the storage levels in the dams, the November analysis might then result in a discretionary

allocation to Eskom for the last 6 months when no allocation was given in May. During periods of above average inflow between May and November it

might be possible that the discretional allocation to Eskom can be increased in November. The results from the November analysis will also act as

an early warning system, as it will already provide some indication whether curtailments will be expected from the May analysis in the following year.

.

Results:

Two scenarios were analysed for the November analysis. Scenario 1 was based on the final accepted scenario as used for the May 2008 anlysis

and no changes to any of the demands or storage control curves were made. The only changes was to include the starting storage as applicable to

1 November 2008 and the inclusion of the short-term stochastic yield characteristics generated for November as the starting month which were then

used as the starting month for the analysis. Since the completion of the May 2008 analysis it was found that an irrigation demand of approximately

36 million m3/a for the area from Torquay to Marksdrift was not captured in the previous demand data base. Part the Bloemfontein Botshabelo

demand abstracted from Knellpoort Dam was previously also allocated to the Orange River Project short-term stochastic yield curves. This was due

to the fact that when the original short-term stochastic yield curves were developed, the Novo Transfer Scheme was not in operation. With the

updated short-term yield curves the portion of the demand supplied from Knellpoort Dam via the Novo Transfer scheme that still need to be allocated

to the Orange River Project short-term yield curves, is much less. For scenario 2 these two elements were corrected, but the rest of the WRPM

setup remained unchanged in comparison with Scenario 1.

Scenario 1:

Results from Scenario 1 indicated that no curtailments is currently required and is also not expected for May 2009. Based on this result it seemed

possible to slightly increase the discretional allocation to Eskom. It is however important to first test this possibility with Scenario 2 that represents a

more accurate description of the current situation.

Scenario 2:

Scenario 2 results did not differ much from the Scenario 1 results as it also clearly showed that no curtailment is currently required and curtailment is

also not expected for the May 2009 analysis. Due to the slightly higher irrigation demand imposed on the system, there was however no room for an

increase in the 71 million m3/a discretional allocation to Eskom.

Fig no. Comments

A-1

A-2

A-3

A-4

A-5

A-6

A-7

A-8 Actual transfers slightly lower than the projected values as final agreed transfer values were not available at the start of the simulations. Final agreed values were slightly lower than those initially estimated.

A-9 Actual releases from Welbedatch Dam to Bloemfontein are close to the projected values

A-10

Actual observed flows for the Ramah canal were obtained and included in the report for the first time in Feb 2009. It is clear that the observed flows exceed the required volume. DWAF Region confirmed that significant flows are flowing

back to the Orange River at the tail end of the canal, which means the excess flows are not necessarily wasted as it can be used by irrigators from the Orange River downstream. The volume returning to the Orange River is however not

measured.

Observed flow through Vanderkloof main canals seem high in comparison with projected flows. DWAF regional office did provide improved observed data spesifically with regards to the Ramah and Orange Riet canal inflow. This however did

not improve the situation with regards to the total releases from Vanderkloof Dam into the main canal. At this stage it seems that the water volumes pumped into the Orange Riet canal at Scheiding pumpstation is fairly close to the

projected values in the model. This means that the excess flow released into the Vanderkloof Main Canal is most probably flowing back to the Orange River via the Ramah canal. If this is the case the water is not directly wasted as it will

be utilised by irrigators abstracting water from the Orange River further downstream. DWAF Regional Office is currently attending to this problem. Data for Dec 2008 to Mar 2009 is not yet available.

Actual releases into Orange Vaal canal are close to and slightly lower than projected values until October 2008 but starting to exceed significantly from November onwards. This was due to almost no flows commimg from the Vaal and Riet

rivers into Douglas Weir during the early rain season, and all the water then need to be supplied from the Orange River. Due to capacity limitations of the pumpstation and canals it was even neseccary to impose restrictions on the users

during this period as at maximum pump capacity the water from the Orange was still insufficient to meet the total requirement.

Observed flows in the Orange Riet canal follow similar pattern as the projected flows. The actual flows from DWAF are slightly higher than the projected flows while the actual flows received from the WUA are lower than the projected

values from Dec 2008 to Feb 2009. DWAF Regional office is following up on this matter. Both observed flow records never the less show that the actual flows are reasonably close to the modelled values.

Gariep Dam reached the storage control curve level and started to spill on 18 February and stopped spilling on 11 March 2009, thus the steep increase in actual volumes released. Actual releases up to end of January 2009 followed the

projected values well.

Actual releases continue to exceed the projected values. DWAF Eastern Cape Regional offices and DWAF Head Office are currently in the process to follow this up and to determine the reason for this high increase in transfer. In March

2009 the total volume released reduced significantly and was again in line with the target value and even slightly lower.

Vanderkloof Dam reached the storage control curve level and started to spill on 27 February and stopped spilling on 18 March 2009, but was still above the SCC until the end of April 2009, thus the increase in the actual volume released.

Actual releases up to end of January 2009 followed the projected values well.

Observed transfer from Knellpoort Dam to Rustfontein Dam are lower than the projected values from January to April 2009. This is due to several causes and includes 1) the fact that this transfer is only partly modelled in the current

WRPM setup and, 2) Knellpoort Dam storage is currently at a very low level (51%) and 3) problems were experiences with the pumps of the Novo transfer as well as at Tienfontein pumpstation.

Table A.1: Comparison of Actual and Target transfers and releases during Planning Year 2008/2009

Annual

Description Units May-08 Jun-08 Jul-08 Aug-08 Sep-08 Oct-08 Nov-08 Dec-08 Jan-09 Feb-09 Mar-09 Apr-09 Transfer

31.00 30.00 31.00 31.00 30.00 31.00 30.00 31.00 31.00 28.25 31.00 30.00 365.25

Releases from Gariep Dam -WRPM Channel 68

Agreed Minimum m3/s 103.870 116.766 57.173 69.499 78.343 67.540 53.515 45.591 46.387 67.775 84.309 96.085 73.816

Releases Million m3/m 278.21 302.66 153.13 186.15 203.07 180.90 138.71 122.11 124.24 165.43 225.81 249.05 2329.46

Discretional releases Million m3/m 52.97 2.25 23.57 0.50 7.18 72.10 12.43 0.00 0.00 0.00 0.00 0.00

Eskom 71 million m3 DWAF 100million m3 Cumulative (actual) 52.97 55.22 78.79 79.29 86.47 158.57 171.00 171.00 171.00 171.00 171.00 171.00

Total agreed releases Cumulative 331.18 636.08 812.79 999.43 1209.68 1462.68 1613.82 1735.93 1860.17 2025.60 2251.41 2500.46

m3/s 123.649 68.588 61.062 58.720 75.483 92.959 95.904 58.318 62.687 435.329 377.841 74.219 130.366

Million m3/m 331.18 177.78 163.55 157.28 195.65 248.98 248.58 156.20 167.90 1062.55 1012.01 192.38 4114.04

Cumulative 331.18 508.96 672.51 829.79 1025.44 1274.42 1523.00 1679.20 1847.10 2909.65 3921.66 4114.04

Releases from Vanderkloof Dam - WRPM Channel 75

Agreed Minimum m3/s 31.440 30.610 33.170 45.093 68.618 89.321 101.822 110.117 103.608 78.891 59.976 45.096 66.441

Releases Million m3/m 84.21 79.34 88.84 120.78 177.86 239.24 263.92 294.94 277.50 192.56 160.64 116.89 2096.71

Discretional releases Million m3/m 6.31 39.33 34.05 16.79 2.33 16.04 0.01 0.00 7.79 15.79 0.00 0.00

Eskom 71 million m3 DWAF 100million m3 Cumulative (actual) 6.31 45.64 79.69 96.48 98.81 114.85 114.86 114.86 122.65 138.44 138.44 138.44

Total agreed releases Cumulative 90.52 209.19 332.08 469.65 649.84 905.11 1169.05 1463.98 1749.28 1957.63 2118.27 2235.15

Actual m3/s 33.619 45.371 48.432 51.273 68.988 100.228 112.805 117.234 110.402 148.636 422.289 85.748 112.490

Million m3/m 90.04 117.60 129.72 137.33 178.82 268.45 302.14 314.00 295.70 362.79 1131.06 222.26 3549.91

Cumulative 90.04 207.65 337.37 474.70 653.51 921.96 1224.10 1538.10 1833.80 2196.59 3327.65 3549.91

Transfers through Orange/Fish tunnel to the Eastern Cape - WRPM Channel 102 & 103

Target m3/s 15.437 6.956 16.170 18.945 20.507 22.550 25.268 25.037 26.444 23.629 22.781 20.507 20.350

Million m3/m 41.35 18.03 43.31 50.74 53.15 60.40 65.49 67.06 70.83 57.67 61.02 53.15 642.21

Cumulative maximum 50.44 72.44 125.28 187.18 252.03 325.72 405.62 487.43 573.84 644.20 718.64 783.49

Cumulative minimum 19.02 27.31 47.24 70.58 95.03 122.81 152.94 183.79 216.37 242.90 270.96 295.41

Cumulative 41.35 59.38 102.69 153.43 206.58 266.98 332.48 399.53 470.36 528.04 589.05 642.21

Actual m3/s 18.864 2.906 21.145 29.659 27.016 29.902 37.342 28.431 35.742 33.995 24.791 29.194 26.553

Million m3/m 50.52 7.53 56.63 79.44 70.03 80.09 96.79 76.15 95.73 82.97 66.40 75.67 837.96

Cumulative 50.52 58.06 114.69 194.13 264.15 344.24 441.03 517.18 612.91 695.89 762.29 837.96

Releases into the Vanderkloof Main Canal - WRPM Channel 104

Target m3/s (Gross) 1.523 0.949 3.682 7.394 14.527 17.865 19.053 12.014 18.918 15.320 9.783 4.109 10.400

m3/s (net as in model) 1.390 0.866 3.361 6.750 13.261 16.308 17.393 10.967 17.269 13.985 8.930 3.751 9.493

Million m3/m 4.08 2.46 9.86 19.81 37.65 47.85 49.39 32.18 50.67 37.39 26.20 10.65 328.19

Cumulative 4.08 6.54 16.40 36.20 73.86 121.71 171.09 203.27 253.94 291.33 317.54 328.19

Actual m3/s 1.950 6.970 7.220 16.960 9.290 19.310 18.350 14.940 18.980 16.190 16.420 0.000 12.224

Million m3/m 5.22 18.07 19.34 45.43 24.08 51.72 47.56 40.02 50.84 39.52 43.98 0.00 385.76

Cumulative 5.22 23.29 42.63 88.05 112.13 163.85 211.42 251.43 302.27 341.78 385.76

Transfers through the Orange Riet Canal

Target m3/s 1.182 0.736 2.857 5.738 11.273 13.863 14.785 9.323 14.680 11.888 7.591 3.189 8.070

Million m3/m 3.16 1.91 7.65 15.37 29.22 37.13 38.32 24.97 39.32 29.02 20.33 8.27 254.67

Cumulative 3.16 5.07 12.73 28.09 57.31 94.44 132.77 157.74 197.06 226.08 246.41 254.67

m3/s 3.256 3.389 3.913 6.711 7.036 11.977 12.648 6.763 6.585 13.061 0.000 0.000 6.233

Actual WUA Million m3/m 8.72 8.78 10.48 17.98 18.24 32.08 32.78 18.12 17.64 31.88 0.00 0.00 196.69

Cumulative 8.72 17.51 27.99 45.96 64.20 96.28 129.06 147.18 164.81 196.69

m3/s 2.635 3.935 5.598 6.899 11.500 12.990 12.830 11.060 13.060 11.693 10.990 0.000 8.593

Actual DWAF Million m3/m 7.06 10.20 14.99 18.48 29.81 34.79 33.26 29.62 34.98 28.54 29.44 0.00 271.16

Cumulative 7.06 17.26 32.25 50.73 80.54 115.33 148.58 178.21 213.19 241.73 271.16

Flow into the Ramah Canal

Target m3/s 0.308 0.192 0.744 1.494 2.936 3.610 3.851 2.428 3.823 3.096 1.977 0.830 2.102

Million m3/m 0.82 0.50 1.99 4.00 7.61 9.67 9.98 6.50 10.24 7.56 5.30 2.15 66.33

Cumulative 0.82 1.32 3.31 7.32 14.93 24.60 34.58 41.08 51.32 58.88 64.17 66.33

Actual m3/s 0.561 0.828 1.426 2.546 3.713 4.839 4.091 2.867 4.576 3.705 4.417 0.000 2.798

Million m3/m 1.50 2.15 3.82 6.82 9.62 12.96 10.60 7.68 12.26 9.04 11.83 0.00 88.29

Cumulative 1.50 3.65 7.47 14.29 23.91 36.87 47.48 55.16 67.41 76.45 88.29

Transfer to Douglas from the Orange at Marksdrift

Target m3/s 0.432 2.138 2.325 5.155 7.826 8.825 2.295 2.677 4.408 3.073 2.556 2.040 3.651

Million m3/m 1.16 5.54 6.23 13.81 20.28 23.64 5.95 7.17 11.81 7.50 6.85 5.29 115.21

Cumulative 1.16 6.70 12.93 26.73 47.02 70.65 76.60 83.77 95.58 103.08 109.92 115.21

Actual m3/s 0.884 1.289 2.473 3.416 5.539 8.177 8.148 5.081 7.517 4.632 3.912 0.000 4.258

Million m3/m 2.37 3.34 6.62 9.15 14.36 21.90 21.12 13.61 20.13 11.30 10.48 0.00 134.39

Cumulative 2.37 5.71 12.33 21.48 35.84 57.74 78.86 92.47 112.60 123.91 134.39

0.07 -2.55 -0.90 -0.71 -0.51 -0.53

Lesotho transfers - WRPM Channel 169

Target m3/s 29.240 33.256 34.298 33.023 28.910 23.921 24.079 21.871 20.213 21.459 22.147 30.262 26.906

Million m3/m 78.32 86.20 91.86 88.45 74.93 64.07 62.41 58.58 54.14 52.38 59.32 78.44 849.10

Cumulative 78.32 164.52 256.38 344.83 419.76 483.83 546.25 604.83 658.96 711.34 770.66 849.10

Actual m3/s 28.442 29.996 30.750 28.946 28.040 20.019 13.738 19.265 17.917 24.111 24.011 25.120 24.197

Million m3/m 76.18 77.75 82.36 77.53 72.68 53.62 35.61 51.60 47.99 58.85 64.31 65.11 763.59

Cumulative 76.18 153.93 236.29 313.82 386.50 440.12 475.73 527.33 575.32 634.17 698.48 763.59

Transfer from Welbedacht to Bloemfontein _ WRPM Channel 35

Target m3/s 1.595 1.595 1.595 1.595 1.595 1.595 1.595 1.595 1.595 1.595 1.595 1.595 1.595

Million m3/m 4.27 4.13 4.27 4.27 4.13 4.27 4.13 4.27 4.27 3.89 4.27 4.13 50.33

Cumulative 4.27 8.41 12.68 16.95 21.08 25.36 29.49 33.76 38.04 41.93 46.20 50.33

Actual m3/s 1.514 1.537 2.124 1.378 1.559 1.576 1.381 1.602 1.587 1.336 1.198 1.898 1.559

Million m3/m 4.06 3.98 5.69 3.69 4.04 4.22 3.58 4.29 4.25 3.26 3.21 4.92 49.19

Cumulative 4.06 8.04 13.73 17.42 21.46 25.68 29.26 33.55 37.80 41.06 44.27 49.19

Transfer from Knellpoort to Rustfontein (Novo Transfer )- WRPM Channel 33

m3/s 0.928 1.207 0.696 0.932 1.110 1.099 1.133 1.257 1.191 1.193 1.049 1.009 1.066

Million m3/m 2.49 3.13 1.86 2.50 2.88 2.94 2.94 3.37 3.19 2.91 2.81 2.62 33.63

Cumulative 2.49 5.61 7.48 9.97 12.85 15.80 18.73 22.10 25.29 28.20 31.01 33.63

m3/s 0.211 0.729 0.677 1.221 1.397 1.124 1.073 0.721 0.000 0.692 0.385 0.583 0.732

Million m3/m 0.57 1.89 1.81 3.27 3.62 3.01 2.78 1.93 0.00 1.69 1.03 1.51 23.11

Cumulative 0.57 2.45 4.27 7.54 11.16 14.17 16.95 18.88 18.88 20.57 21.60 23.11

Actual

Target

Actual

0.00

500.00

1000.00

1500.00

2000.00

2500.00

3000.00

3500.00

4000.00

4500.00

May-08 Jun-08 Jul-08 Aug-08 Sep-08 Oct-08 Nov-08 Dec-08 Jan-09 Feb-09 Mar-09 Apr-09

Cu

m R

ele

ase

s (

milli

on

m3)

Months

Fig A-1: Releases from Gariep Dam

Total agreed releases Actual

0.00

500.00

1000.00

1500.00

2000.00

2500.00

3000.00

3500.00

4000.00

May-08 Jun-08 Jul-08 Aug-08 Sep-08 Oct-08 Nov-08 Dec-08 Jan-09 Feb-09 Mar-09 Apr-09

Cu

m R

ele

ase

s (

milli

on

m3)

Months

Fig A-2: Releases from Vanderkloof Dam

Total agreed releases Actual

0.00

100.00

200.00

300.00

400.00

500.00

600.00

700.00

800.00

900.00

May-08 Jun-08 Jul-08 Aug-08 Sep-08 Oct-08 Nov-08 Dec-08 Jan-09 Feb-09 Mar-09 Apr-09

Cu

m T

ran

sfe

r (m

illi

on

m3)

Months

Fig A-3: Transfers through Orange/Fish tunnel to the Eastern Cape

Target Actual Cumulative maximum Cumulative minimum

0.00

50.00

100.00

150.00

200.00

250.00

300.00

May-08 Jun-08 Jul-08 Aug-08 Sep-08 Oct-08 Nov-08 Dec-08 Jan-09 Feb-09 Mar-09 Apr-09

Cu

m T

ran

sfe

r (m

illi

on

m3)

Months

Fig A-5: Transfers through the Orange Riet Canal

Target Actual WUA Actual DWAF

0.00

10.00

20.00

30.00

40.00

50.00

60.00

70.00

80.00

90.00

100.00

May-08 Jun-08 Jul-08 Aug-08 Sep-08 Oct-08 Nov-08 Dec-08 Jan-09 Feb-09 Mar-09 Apr-09

Cu

m F

low

in

to C

an

al (m

illi

on

m3)

Months

Fig A-6: Flow into the Ramah Canal

Target Actual

0.00

10.00

20.00

30.00

40.00

50.00

60.00

May-08 Jun-08 Jul-08 Aug-08 Sep-08 Oct-08 Nov-08 Dec-08 Jan-09 Feb-09 Mar-09 Apr-09

Cu

m T

ran

sfe

r (m

illio

n m

3)

Months

Fig A-9: Transfer from Welbedacht to Bloemfontein

Maximum Transfer Capac ity Actual

0.00

100.00

200.00

300.00

400.00

500.00

600.00

700.00

800.00

900.00

1000.00

May-08 Jun-08 Jul-08 Aug-08 Sep-08 Oct-08 Nov-08 Dec-08 Jan-09 Feb-09 Mar-09 Apr-09

Cu

m T

ran

sfe

r (m

illi

on

m3)

Months

Fig A-8: Lesotho transfers

Maximum Transfer Capacity Actual

0.00

20.00

40.00

60.00

80.00

100.00

120.00

140.00

160.00

May-08 Jun-08 Jul-08 Aug-08 Sep-08 Oct-08 Nov-08 Dec-08 Jan-09 Feb-09 Mar-09 Apr-09

Cu

m T

ran

sfe

r (m

illi

on

m3)

Months

Fig A-7: Transfer to Douglas from the Orange at Marksdrift

Target Transfer Actual

0.00

50.00

100.00

150.00

200.00

250.00

300.00

350.00

400.00

450.00

May-08 Jun-08 Jul-08 Aug-08 Sep-08 Oct-08 Nov-08 Dec-08 Jan-09 Feb-09 Mar-09 Apr-09

Cu

m R

ele

as

es

(m

illio

n m

3)

Months

Fig A-4: Releases into the Vanderkloof Main Canal

Target Actual

0.00

5.00

10.00

15.00

20.00

25.00

30.00

35.00

40.00

May-08 Jun-08 Jul-08 Aug-08 Sep-08 Oct-08 Nov-08 Dec-08 Jan-09 Feb-09 Mar-09 Apr-09

Cu

m T

ran

sfe

r (m

illi

on

m3)

Months

Fig A-10: Transfer from Knellpoort to Rustfontein (Novo Transfer)

Target Actual

C omment s :

1 On 5 M ay 2008, storage within Gariep Dam was at 89.7% of its live storage capacity.

2 On 2 June 2008, storage within Gariep Dam was at 86.3% of its live storage capacity.

3 On 7 July 2008, storage within Gariep Dam was at 89.4% of its live storage capacity.

4 On 4 August 2008, storage within Gariep Dam was at 86.2% of its live storage capacity.

5 On 1 September 2008, storage within Gariep Dam was at 82.0% of its live storage capacity.

6 On 6 October 2008, storage within Gariep Dam was at 75.1% of its live storage capacity.

7

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9 On 5 January 2009 the storage within Gariep Dam was 75.7% of its live storage capacity.

10 On 18 February 2009, Gariep Dam had reached its full supply capacity and it was spilling.

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On 3 November 2008, storage within Gariep Dam was at 68.3% of its live storage capacity. Gariep actual storage is start ing to

follow levels lower than the median projected value. This might be as result of the higher t ransfers through the Orange Fish Tunnel

Gariep reached its lowest storage level in December (64%) and has since recovered signif icant ly and is just above the projected

median storage level

On 2 M arch 2009, Gariep Dam was at its full supply capacity and it was spilling. On 12 M acrh 2009 the dam stopped spilling.

On 6 April 2009, storage within Gariep Dam was at 98% of its live storage capacity and by the end of April the dam was at 95% of

its live storage capacity.

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1 On 5 M ay 2008, storage within Vanderkloof Dam was at 89.2% of its live storage capacity.

2 On 2 June 2008, storage within Vanderkloof Dam was at 96.9% of its live storage capacity.

3 On 7 July 2008, storage within Vanderkloof Dam was at 98.7% of its live storage capacity.

4 On 4 August 2008, storage within Vanderkloof Dam was at 98.9% of its live storage capacity.

5 On 1 September 2008, storage within Vanderkloof Dam was at 99.0% of its live storage capacity

6 On 6 October 2008, storage within Vanderkloof Dam was at 98.0% of its live storage capacity

7 On 3 November 2008, storage within Vanderkloof Dam was at 96.5% of its live storage capacity

8 On 1 December 2008, storage in Vanderkloof Dam reduced to 94.4% of its live storage capacity

9

10 On 27 February 2009, Vanderkloof Dam had reached its full supply capacity and was spilling.

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By the end of January 2009, the storage in Vanderkloof Dam reduced to 83.7% . This is in line with the

projected values but still above the median storage.

On 2 M arch 2009, Vanderkloof Dam was at its full supply capacity and it was spilling. On 19 M arch the

dam stopped spilling.

On 6 April 2009, storage within Vanderkloof Dam was at 98.5% of its live storage capacity and by the

end of April the dam was at 96% of its live storage capacity.

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C omment s :

1 Based on the storages as given on the individual sheets for Gariep and Vanderkloof.

2

3

4 At the end of M arch 2009 both dams had stopped spilling.

5 At the end of April 2009 the dam levels for both dams were just above the median.

6

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The combined storage for Gariep & Vanderkloof has recovered well by the end of January 2009 and is not far

below the median projected storage.

The combined storage for Gariep & Vanderkloof has signif icant ly recovered even further due to good rains and

both reached the full supply levels and start spilling towards the end of February 2009.

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C omment s : General co mment s

1 On 5 M ay 2008, storage within Welbedacht Dam was at 86.1% of its live storage capacity.

The area-capacity data that was used the

f irst runs for Welbedacht is outdated and

this data will be updated in the next runs.

2 On 2 June 2008, storage within Welbedacht Dam was at 95.1% of its live storage capacity.

3 On 7 July 2008, storage within Welbedacht Dam was at 89.8% of its live storage capacity.

4 On 4 August 2008, storage within Welbedacht Dam was at 93.6% of its live storage capacity.

5 On 1 September 2008, storage within Welbedacht Dam was at 98.4% of its live storage capacity

6 On 6 October 2008, storage within Welbedacht Dam was at 38.0% of its live storage capacity

7 On 3 November 2008, storage within Welbedacht Dam was at 57.3% of its live storage capacity

8 On 1 December 2008, storage within Welbedacht Dam was at 97% of its live storage capacity

9 By end of January 2009 the storage in Welbedacht recoverd to 92.7% and is almost at the median projected storage level.

10 On 2 February 2009, storage within Welbedacht Dam was at 78.14% of its live storage capacity

11 On 2 M arch 2009, storage within Welbedacht Dam was at 84.34% of its live storage capacity

12

On 6 April 2009, storage within Welbedacht Dam was at 91% of its live storage capacity and on the 13 April 2009 the dam reached its full

supply capacity and dropped down to 92% of its live storage capacity by the 20th of April 2009.

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C omment s :

1 On 5 M ay 2008, storage within Knellpoort Dam was at 70.4% of its live storage capacity.

2 On 2 June 2008, storage within Knellpoort Dam was at 69.0% of its live storage capacity.

3 On 7 July 2008, storage within Knellpoort Dam was at 66.6% of its live storage capacity.

4 On 4 August 2008, storage within Knellpoort Dam was at 63.3% of its live storage capacity.

5 On 1 September 2008, storage within Knellpoort Dam was at 60.5% of its live storage capacity

6 On 6 October 2008, storage within Knellpoort Dam was at 56.0% of its live storage capacity

7

8 On 1 December 2008, storage within Knellpoort Dam was at 50.9% of its live storage capacity

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On 3 November 2008, storage within Knellpoort Dam was at 53.0% of its live storage capacity. Observed

storage t rajectory very low. This is expected to be as result of the fact that only part of the system is

current ly modelled in the WRPM setup and that f lows in the Caledon were to low to be able to pump water

into Knellpoort Dam

At the end of January 2009 the storage in Knellpoort Dam has reduced to a concerning 46.8%. The f low is

current ly suff icient in the Caledon for pumping purposes at Tienfontein Pump stat ion, but the pumps are not

working and Bloemwater is in the process to repair the pumps.

On 2 M arch 2009, storage within Knellpoort Dam was st ill at 49% of its live storage capacity and this slow

rise in the dam level is due to the fact that there are transfers from Knellpoort to Rustfontein dam.

On 2 February 2009, the pumps were back in operat ion and the storage within Knellpoort Dam was at 49%

of its live storage capacity

On 06 April 2009, storage within Knellpoort Dam was st ill at 49% of its live storage capacity.

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C omment s :

1 On 5 M ay 2008, storage within Katse Dam was at 96.1% of its live storage capacity.

2 On 2 June 2008, storage within Katse Dam was at 93.8% of its live storage capacity.

3 On 7 July 2008, storage within Katse Dam was at 90.5% of its live storage capacity.

4 On 4 August 2008, storage within Katse Dam was at 87.1% of its live storage capacity.

5 On 1 September 2008, storage within Katse Dam was at 86.8% of its live storage capacity

6 On 6 October 2008, storage within Katse Dam was at 86.4% of its live storage capacity

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On 3 November 2008, storage within Katse Dam was at 89.4% of its live storage capacity. Observed

storage project ion higher than simulated due to smaller transfer volume than expecxted and increased

transfer from M ohale to lower the water level in M ohale Dam for reparation work.

Katse Dam started to spill early in January 2009 and is well above the median projected storage. This is

part ly due to the lower actual than modelled transfers to the Vaal as well as transfers f rom M ohale to

Katse to keep levels low in M ohale Dam.

At the end of M arch 2009, the storage at Katse Dam was at its Full Supply Level.

On 6 April 2009, the storage at Katse Dam was at its Full Supply Level.

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C o mment s : General co mment s

1 On 5 M ay 2008, storage within M ohale Dam was at 75.3% of its live storage capacity.

Observed storage levels are

high in M ohale Dam because

the LHDA did not release

the f lows during maintenace

of the dam wall as init ially

indicated.

2 On 2 June 2008, storage within M ohale Dam was at 76.5% of its live storage capacity.

3 On 7 July 2008, storage within M ohale Dam was at 79.2% of its live storage capacity.

4 On 4 August 2008, storage within M ohale Dam was at 77.3% of its live storage capacity.

5 On 1 September 2008, storage within M ohale Dam was at 69.2% of its live storage capacity

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On 6 October 2008, storage within M ohale Dam was at 61.1% of its live storage capacity. The observed storage levels in the dam has

dropped signif icant ly and is due to the fact that LHDA is releasing water to Katse Dam as they are busy with maintenance on the dam wall.

They are planning to lower the dam up to the level of 2053 and plan to release to Katse for the next 4 to 5 months depending on the rain

and the water levels in Katse dam.

On 3 November 2008, storage within M ohale Dam was at 67.3% of its live storage capacity and a reduct ion in storage is evident towards

the end of the month (52%) due to t ransfers to Katse Dam. (Also see Katse observed storage t rajectory)

The storage raised again towards the middle of January and then drop slight ly to end of January (55.5%), which could be due to t ransfers

to Katse following the steep rise in storage at Katse Dam.

On 6 April 2009, storage within M ohale Dam was at 69% of its live storage capacity and by the end of April 2009 the dam was at 66% of

its live storage capacity.

On 2 February 2009, storage within M ohale Dam was at 66.9% of its live storage capacity

On 2 M arch 2009, storage within M ohale Dam was at 72.6% of its live storage capacity

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1 Based on the storages as given on the individual sheets for Katse and M ohale.

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The combined storage is well above the median projected value due the above average rainfall as well

as result of the slight ly lower actual t ransfer than that included in the model for the M ay 2008 analysis

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1 Average monthly f low at Oranjedraai in M ay 2008 was 20.68 cumecs. Observed f low close to median.

2 Average monthly f low at Oranjedraai in June 2008 was 20.02 cumecs. Observed f low is above the median simulated f low.

3

4

5 Data for February and M arch 2009 is not yet available.

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Observed f low from July to Nov 2008 was below the median simulated f lows. In this period a signif icant drop can be seen in the

storage at Gariep Dam

For Dec and Jan the abserved f lows was clearly above the median projected f lows. This resulted in the signif icant recovery in

storage that occurred in Gariep Dam during Dec. and Jan.

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Flow at D1H009 ( Oranjedraai)

C omment s :

1 Average monthly f low at Aliwal North in M ay 2008 was 23.65 cumecs.

2 Average monthly f low at Aliwal North in June 2008 was 30.85 cumecs.

3 Average monthly f low at Aliwal North in July 2008 was 17.03 cumecs.

4 Average monthly f low at Aliwal North in August 2008 was 13.07 cumecs. Observed f low close to median simulated f low.

5

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7 Data for February and M arch 2009 is not yet available.

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For the period M ay to November relat ive low f lows were experienced which agree with those observed at Oranjedraai although

slight ly higher. This can be expexted due to contibutions from the incremental catchment.

For the months Dec & Jan the observed f lows at Aliwal is signif icanly lower than the f lows at Oranjedraai which can not be

possible. DWAF Regional of f ice indicated that changes were made to the Aliwal gauge and a new DT is required. The current

observed f lows from the Aliwal gauge can therefore not be regarded as accurate.

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Appendix E

Gariep and Vanderkloof hydro-power related operating rule

Appendix F

Additional Analysis Banking Options