There seems to have been little coverage of this in the press, but with effect from 21st September 2014, DEWA (Dubai Electricity & Water Authority) has increased the security deposits required on taking up residency in a property.
The security deposit for an apartment has increased from AED 1,000 to AED 2,000 and for villas the amount has increased from AED 2,000 up to AED 4,000. In all cases an administration charge of AED 110 is also payable.
The application forms have also been changed so you need to ensure that you have the right ones as old forms are not being accepted at all DEWA offices. These new forms no longer ask for passport detail, but for your residency visa number instead
Link to DEWA website, although this has yet to be updated.