r - part - usaid

exploratorf drfl3ing, and the objectives QP the Central
Rmgelands exploratory drilling progxan incllltdes the
c~nstruction of pruductian wells, The different variables which
axe assuned for the two programs are explained in detail below.
The w2ole operatfan of constructing a well is assurnod, 141"
costing purposes, to consist of six separate phases . These six
phases are hydraga03egy, drilling, well logging, well testing,
civil works construction, and pump installation, The m&al*s
treatment of each phase is described in some detail below, The
significance of each phase in terms of its contribution to the
total costs is shown in Pigures 2.4.1 and 2.4-2 fox the
construction of wells equipped with diesel pumps, and in Figures
2.4.3 and 2*4*4 far those equipped with hand pumps.
The proportion of total costs far labour, materials, and
transport and equfpaent, for wells equipped with diesel pumps,
is shown in figures 2-4.5 and 2.4.6 fox the two regions. Figure
2.4.7 shows these tot91 costs split between direct costs,
repairs ane nainte~ance charges, and capital recovery charges-
The model contains well over two hundred variables, all of
which are interrelated. The benefiss of a computer model axe
that it is dynamic, rather than static, and the figures
presented here should be viewed as the nost accurate avaifable
at this tine. Each of the Tab3es 1 throuqh 9 af Appendices
4.4.1 and 4.4.2 is supported by a set of notes. Many of the
variables are pib bedded i.kcbese notes. The nodel i s set up
zsing the Lotus ' SYMPHONY software package.
4 Overall Variables Used In the Model
The model is largely self-expla~atory, and will not be
described in extensive detai; here. A number of variables are,
however, worthy of sone discussion.
-
4.1.1.1. Currency Sxckai-i~e ~ zre
An exchange rate of So.Sh.83, ecgial to USS1 has been used
throughout. Three exc5ange rates are currently in use in
S~ma19a. The nafficial ratem of 61:f is used for all
governzent-to-govexnnent transactions. A "comercial rateM of
83;L is currently operaking, though the supply of funds at this
rate is scarce. The *$narket rateH is floatfng ot approximately
120:l. The local currency component is less than 4% of the
total program cost, so this is not z critical variable in the
node> (Appendix 4.4.1, Table 21).