The standing and importance of the subsector agronomy in regional economics as well as in strengthening of the social- economic processes in Zanjan province call for the means enabling one to make maximum use of the valuable capacities and potentials available in the above- mentioned subsector to enhance its development. One of those means to be strongly stressed upon is proper planning. Proper planning itself requires on identification and determination of the effective coefficients affecting the level of development in the subsector. Realizing the importance of the role of physical and developmental infrastructures in the development of the subsector agronomy, in the present study it is tried to make an evaluation of the effective factors as regards the credits allocated to water harness and transfer in the provinces,s rural areas. Other important affecting factors have also been taken into consideration and a final analysis of the obtained results made. Time series data released by Statistical Center of Iran Ministry of Agriculture, Agricultural Bank, Central Bank, Department of Energy, Meteorological Organization, as well as Budget and Planning Organization have been made use of in the ongoing research work. A combination of the methods of "Principal component Analysis" and "Numerical Taxonomy" was employed to find out the developmental level for any of the years within the time period of 1989-2008. The resulting figures as the dependent variable us. Factors effective in agricultural development as the independent variables were inserted in a regression model. This model came out to be indicative of the fact that the allocation of governments Developmental credits to "Water harness and transfer" in the rural areas of Zanjan Province has (with an exception of two time periods) positively and significantly affected the farming level of development. The result indicate that the combinatorial index of farming development has improved by 0.000717 units per 1000 billion Rials of increase in constructional credit investment in the field of "water harness and transfer". The closer the combinatorial index of farming development to Zero figure, the more developed the area is assumed to be.