People called for action after hardcore-laden lorries followed by mobile homes arrived earlier this month in the Hovefields area of Wickford.
Basildon Council is taking legal action over alleged planning breaches.
Leader Phil Turner said they were dealing with "people who were prepared to defy a high court order".
The Hovefield site - which is subject to an injunction preventing further development - is less than three miles (5km) by road - from the Dale Farm traveller site in Wickford.
Dale Farm was Europe's largest traveller site before about 80 families were evicted from unlawful plots in 2011.
A committal hearing date will be held on 5 April, for an alleged breach of the injunction banning more development at Silva Lodge Kennels in Hovefields Avenue.
At a meeting on Thursday, Mr Turner claimed they were dealing with breaches on multiple sites, with various plots of land subject to different ownership and circumstances.
The only way they could be sure certain "green belt" plots at Hovefields were restored would be by "following the letter of the law" and gathering as much evidence as possible.
He said: "Regrettably we are dealing here with people who are prepared to defy a High Court Order, despite the potential consequences to themselves."
The Hovefields Residents Association ad previously warned that if the council did not act urgently, they could "have a Dale Farm II".
A council is to go the High Court over a traveller site in Essex that residents fear could become "Dale Farm II".