Report of a committee on a plan for cleansing the drains of Black Town.

Date:
1856
Catalogue details

Licence: Public Domain Mark

Credit: Report of a committee on a plan for cleansing the drains of Black Town. Source: Wellcome Collection.

    96/105 (page 88)
    MEMORANDUM ON THE ADYAIi BASTS'. The total area of the basin is 21G square miles of which ffc„*a , , the hund of the old tank proposed to he restored, 88 ^ ^ Z , * 178 square miles ; hut in this area there are 61 ta J of various sizes from 20 an-tv-tR/■». i •■ preaas square mile. * °f * m,lc t0 G°° acres * H of a squai^irregat° °f ^ <>f all these tanks is about 13, Th^^ean dePth » Probably about 4 feet and their aggregate COn tents=|Xl3ix3)097,600=56 millions cubie yards. & The contents of the proposed new reservoirs will be about as follows :- Millions Cubic yard's. AT 7| by 3,097,600 by f= 31 ■New tank below the present one 2*] Old tank restored. Square Miles. J| by 3,097,600 by 2 = Total. 15% •46| From a ram table whieh has been calculated in this office by omitting he first half umh of every fall in order to aUow for absorption, ifc appears that the mean water supply of that portion of the basin which is situated above the old tank has been on an average of 49 years, from 1803 to 1852 as foflows :— The area of this portion of the basin being 178 square miles. The quantity in May has been 178 by 3,097,600 by 2-005 June July Aug. Sept. Oct. Nov. Dec. Jan. 3G- •812 Millions Cubic yards. 32 36- 2-084 178 by 3,097,600 by- 178 by 3,097,600 by- 3( 178 by 3,097,600 by— J 36' 178 by 3,097,600 hj~ 178 by 3,097,600 by-*- 178 by 3,097,600 by'958 36* 4-233 178 by 3,097,600 by 178 by 3,097,600 by-6^-- SIS' '— 36- '694 12i -L-'2 32 48 52 183 6<±i 104 Total... 578 The contents of all the reservoirs, those now existing and those proposed, being 102 millions cubic yards-we may judge from the foregoing calculation'