X2H036: KOMATI RIVER AT KOMATIPOORT:

• Access road has been damaged and a stretch of 300 meters needs to be repaired. Preferable, the road surface must be treated with a soil-cement mixture to ensure proper access during all conditions. Costs involved is estimated at R 80 000.

• The station was equipped with a cell-phone communication system and was, together with all other measuring equipment (Logger, probe, cable, mechanical recorder, solar panel, regulator and modem), destroyed since it was submerged by more than 3.0 meter of floodwaters. Estimation of costs involved for the replacement of the equipment is R 60 000.

• Structural damage could not be evaluated since it was completely submerged. Conclusions made from photo material gave an indication of damages on both riverbanks and reparations could run into thousands. Depending on the degree of damage, reparations are estimated at R 150 000. Experience has learned that the crest irons on the structure are damaged with every flood and since this will be no exception, the replacing thereof will definitely be necessary. Costs is estimated on R 50 000 and will include the repairing of some concrete erosion.

X3H021: SABIE RIVER AT KRUGER GATE

 FLOOD PEAK CALCULATED AT 6 864 M³/S 

• The road to the station is completely inaccessible and photo coverage was obtained from a helicopter flight over the station. Indications from these photos are that the station has been outflanked on both sides and will have to be repaired with masses of soil or alternatively, reinforced concrete walls. The total cost including reparations to the access road, is estimated at approximately R 1 000 000.

• The international status of this station requires the availability of real time data and therefore it was equipped with a satellite transmission system. Indications are that this equipment together with the entire other standard measuring devices were flooded and destroyed. Replacing all these equipment could cost as much as R 150 000.

• Except for some erosion damages on the concrete surface of the structure, not many other damages are suspected.

 FLOOD PEAK CALCULATED AT 2 750 M³/S 

• As in the case of the Sabie River weir, access to this station was also not possible but photo coverage obtained from a helicopter flight, helped to evaluate possible flood damages. (See photo on next page) The main issue at this station could be the repairing of the access road since several tributaries must be crossed on the way to the gauging weir. Although tourists use these roads as well, the Department will have to contribute to a certain extend, especially in the repairing of the last 500 meters to the station.

• Structural repair works will include the raising of a 150 meter long flank wall and is estimated to be R 70 000.

• The station has a history of silt/sand problems and heavy equipment will be needed to clean the upstream pool. Possible cost could be R 50 000.

• Instrumentation consisted of a mechanical recorder, electronic logger and a cell-phone communication system. Replacing this equipment will cost approximately R 50 000.

COST ESTIMATION TO GET STATION OPERATIONAL AGAIN: R 600 000

X3H006: SABIE RIVER AT PERRY’S FARM

• The station, which is situated 20 meters downstream of the bridge, was by-passed on both banks and besides the extensive damage to the weir, the recorder hut was totally demolished. Structural damage to the rest of the weir is difficult to assess since it was submerged during the time of observations. Repairing the flanks will be very costly and is estimated at R 250 000.

• A complete relocation of the recorder tower will be required and together with the replacing of the necessary equipment, costs can be as much as R 200 000.

• The station has a history of being outflanked on the left bank and huge sums of money were spent to overcome this problem. The photo clearly indicates that the problem repeated itself and, in order to divert the river to the weir, it will require the construction of a cut-off wall from the weir to the upstream diversion wall. This wall was previously constructed in order to direct the flow towards the weir and a similar method must be applied. Alternatively, the reconstruction of the weir at the upstream wall should be investigated. Civil works to get the station operational again could be as high as R 1 400 000.

• Expensive communication equipment was installed at this station since it has both an important international and operational status regarding flood warning and water distribution. Therefore, the station was furnished with expensive satellite and cell-phone communication systems. Replacing thereof is essential and will cost approximately R 120 000.

• The exact extent of the structural damage was difficult to assess but precautionary measures such as installing Armour-flex must be taken to ensure the stability of both flank walls. Cost is estimated at approximately R 50 000.

• This station was previously outflanked on the Right Bank and various precautionary measures were taken to prevent the repetition thereof. In spite of those measures, the station was completely outflanked again, resulting in a complete demolishing of the right flank cut-off wall. The replacing costs of the wall will be approximately R 120 000 which is necessary if measurements are to be continued.

• Two recorder towers were washed away together with R 50 000 worth of instrumentation. The replacing costs thereof is estimated at R 100 000.

X3H011: MARITE RIVER AT INYAKA (DOWNSTREAM OF INYAKA DAM)

• Two recorder towers including instrumentation worth R 65 000 were washed away. The replacement thereof, including two reinforced concrete towers, could amount to R 160 000.

• Again, an accurate assessment of structural damages was not possible during above observation but both riverbanks need protection against further erosion. Depending on the area that needs to be protected, the cost could amount to R 25 000.

• The access road is badly eroded and needs to be treated with a cement and soil mixture for proper access to the station at all time. Costs is estimated at R 75 000.

X3H015: SABIE RIVER LOWER SABIE CAMP (K. N. P.)

 FLOOD PEAK CALCULATED AT 12 000 M³/S 

• Both the left and Right Bank recorder towers were flooded, resulting in the complete destruction of the electronic logger and mechanical recorder. The 100 meters vented data cable connected to the logger was swept away and must be replaced. Since the electronic equipment consisted of an OTT-log and compliant equipment, the estimated replacing costs can be as much as R 82 000.

• Although damages on the Right Bank are still difficult to assess, recent photo coverage indicated a definite damage of the left bank and the Armour-flex protection must be replaced. Depending on the damaged area, a preliminary cost estimation is in the order of R 100 000.

• Further structural damage is not yet possible to assess but, indications are that the stilling well for the probe is broken and must be replaced. Possible cost is estimated at R 24 000

TOTAL ESTIMATION FOR REPAIR WORKS: R 800 000

X3H004: NORTH SAND RIVER AT DE RUST (HAZYVIEW)

• The recorder tower including measuring instrumentation worth R 26 000 are washed away.

• Exact structural damage is not yet possible to assess but indications are that the station has been outflanked on both sides. Reparation costs can be as much as R 60 000 including erosion protection and the replacing of certain damaged sections of the gauging weir.

• The recorder tower will have to be raised by approximately 2.0 meters to limit future damage of expensive instrumentation may cost a additional R 60 000.

• The national Road Bridge was also by-passed on both sides but must be repaired by the Provincial Roads Department.

TOTAL ESTIMATED REPAIR COST: R200 000

FLOOD DAMAGES IN THE CATCHMENT OF THE UPPER ELEPHANTS RIVER

B2H015: WILGE RIVER AT ZUSTERSTROOM:

• The recorder tower was flooded and the electronic instrumentation was damaged beyond repair. Replacing the equipment will cost R 20 000.

• Raising the tower by 2.0 meters and replacing the existing steel hut with a reinforced concrete hut, will cost approximately R50 000.

TOTAL ESTIMATED COSTS: R 70 000

B3H017: ELEPHANTS RIVER AT LOSKOP DAM (DOWN STREAM

• The access bridge to the recorder tower was washed away and must be replaced. Estimated costs is R 32 000. The instrumentation was also damaged and will cost R 22 000 to be replaced.

TOTAL ESTIMATED REPAIR COST: R 54 000

PRELIMINARY ESTIMATION OF THE TOTAL DAMAGES CAUSED BY THE RECENT FLOODS CAN BE SUMMARIZED AS FOLLOWS:

INSTRUMENTATION  :   R 930 000

R 4 975 000

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