New '\\'ati:i{\\(>i;ks itti; Poirr Ki.izAitinir, Soi'iii Afi.tca. 7'> 



frc'iu the Pi»rt Eliz.iln'th Tow ii Hall. Tlif liulk Kivcr KestM\ oii- lius a 

 capacitv of 124 milliuii gallons, aiul is sitiiutod on the Bulk l^iver 

 about 30 miles from the Poit Elizabeth Town Hall. The dam for the 

 former reservoir is built of cyclopean rubble and is straight on plan, 

 while the latter is built of cyclopean rubble with concrete block facing 

 and is curved upstream to a radius of 300 ft. Both dams ha\e been 

 reinforced with iron rods and railway metals to take up temjierature 

 strains. The filter plants, which are i)laced as near the dams as pos- 

 sible, are known as the Candy Automatic Air Compressing and Aerating 

 Polarite Filters. The filter plant is designed of steel cylinders 8 ft. 



ins. diameter and !> ft. 6 ins. high, which contain sand, gravel and 

 polarite or oxidium : the water enters at the to^T on a perforated plate 

 and then falls through a colunui of air on to another perforated plate 

 immediately above the top layer of sand. The filter is cleansed by 

 reversing the flow and passing filtered water upwards through the 

 beds, thus washing away all scum and dirt into a washout pipe ; this 

 only takes fron^ 10 to 15 minutes. The six filters at Sand River deal 

 vith 1 million gallons, and the three filters at Bulk River with 



1 million gallons per da)'. Both sets of filters are housed, the former 

 in a concrete building with iron roof and the latter in an iron 

 building. The pipe line is about 40 miles long and passes through 

 Aery rugged country for about 20 miles : this necessitated a large 

 number of river and kloof crossings and a tunnel lined with concrete 

 a little o\er a quarter of a iiiile in length. On one section of the 

 line it was necessary to carry the pipes on piers for a considerable 

 distance ; in this case the pipes were carried on delta metal I'ollers 

 and were covered with a hood, while expansion joints were fixed 

 every 300 to 400 feet. The pipes are of mild steel and are joined with 

 Kimberley collars. Tiie pipes were double dipped before lea-sing 

 England, and repainted, where the coating was damaged during 

 transit or la3'ing, after the pipes were laid in the trench. The covered 

 service reservoir in St. George's Park, Port Elizabeth, is of an orna- 

 mental character and has a capacity of 2 million gallons. It is 200 ft. 

 diameter and the water is 10 ft. 6 ins. deep. The roof is reinforced on 

 the Kahn sj^stem, and the floor is made of concrete with bitumen 

 sheeting sandwiched in between two layers 4 ins. and 5 ins. thick 

 lespectiveh'. The municipality has purchased nearly 22,000 acres of 

 land, the greater portion of wliich is on the catchment area. Ct)m- 

 pensation has been paid for water-rights to the extent of £25,000. 

 The estimated cost of the scheme was ,£360,000, but was carried out 

 departmentallv to the designs of and by the author for the sum of 

 £320,000. 



