700 kPa is the pressure of a reservoir of water placed at an height of 70 metres over the turbine that is free flow at the output. You can place it in the formula as 70 metres of head. Power is generated by the loss of energy of water when it comes down from 70 metres or when loses 700 kPa when driven by a pump. The formula you quoted gives W/s but 10 kW is generally meant as 10 kW/hkWh to get quantity of water required in an hour.