You should have Manual mode. This will enable you to engage bulb for the shutter speed, up to a maximum of 5 mins. You need to hold down the shutter button all this time though.
And aperture wise, you can go down to f8 on wide angle. Were you using a tripod? Mebbe you'd wanna consider the remote cable for this type of long exposure shots too.
For your current picture, what do you wish to portray? I believe the larger aperture (F4) may have caused all those bright spots for the street lamps. Mebbe you'd like to try out a few more shots at different shutter speeds, apertures, etc to see which would give you your best effect of this Pandan reservoir.