Former Frankston City Council infrastructure manager Andrew Williamson has been jailed for 12 months.

The 45-year-old had been earning $175,000 a year.

But he was insecure and this wasn't enough to keep up with the facade of wealth he'd created for his partner.

Over eight months between 2016 and 2017, Williamson submitted fraudulent invoices worth a total of $460,870 on behalf of an electrician.

The work either wasn't done or its value was inflated significantly.

The electrician had previously done renovation work on the home Williamson shared with his partner.

After receiving a letter of demand for more than $8000 for the renovations, he appointed the electrician as an approved supplier and provider for the council.

Williamson kept $346,554 of rorted funds and the rest went to the electrician.

The senior council officer spent nearly $160,000 on a hydro-electric project his partner was working on for poverty-stricken Nepalese communities.

He used $70,096 to pay off credit card debt, and $76,000 to artificially boost his wage, and fund renovations, restaurant meals, cruises and weekends away.

Williamson also put $20,000 into a business venture that failed, repaid his mother for a $15,000 loan and settled for $5544 debt with Telstra.

Sentencing County Court Judge George Georgiou on Thursday labelled the man's conduct "reprehensible, and deserving of condemnation and punishment".

Williamson had developed an intense need to impress his girlfriend.

They started a relationship after Williamson in 2014 left his wife and family in Queensland and moved to Melbourne.

But he lied to his new partner, saying he was divorced and earned much more money than he actually did.

Williamson's financial state deteriorated and he was drinking up to 12 stubbies a night from the stress.

He pleaded guilty to misconduct in public office, obtaining property by deception and attempting to obtain property by deception.

None of the stolen money has been repaid.

Judge Georgiou said Williamson did not appear to have taken full responsibility for his crimes.

He must spend two-and-a-half-years on a community correction order when he gets out of jail.

Australian Associated Press