If the Council shall declare that it is expedient to construct, improve, enlarge, extend or repair the present electrical utility known as The Hart Hydro, the cost of which must be met by bond issues or loans, then the question of raising the amount required for any such purposes shall be submitted to the electors of the City at its next regular election or at a special election called for that purpose by the Council. The Council may make any improvements and extensions to the existing Hydro plant as the normal growth of the plant requires when the cost of such improvement and extension may be met by the expenditure of any accumulated surplus, and no expenditures for the improvement or extension of the Hydro plant shall be made in excess of this amount except by reference to the electors as herein provided.