In the case of an apparent emergency which requires an immediate purchase of supplies, services or construction, the city manager shall be empowered to secure by open market procedures, at the lowest obtainable price, any supplies, services or construction, regardless of the amount of the expenditure, when such procurement is essential to prevent delays in the work of the city which may vitally affect the life, health or welfare or convenience of the citizens. A full report of the circumstances of an emergency purchase shall be filed by the city manager with the city council at the next regular city council meeting following the purchase, shall be entered in the minutes of the city council and shall be open to inspection.