Funding of £139,000 has so far been secured for the project, centred on the Old River Bed in the Bagley area of Shrewsbury, with a licence application set to be submitted next week to Natural England.
The new arrivals will be released into a large enclosure and will be the first beavers in Shropshire since the species was hunted to extinction in the UK in the 16th century.
The industrious mammals have already been reintroduced to several other areas of the country in recent years, including Machynlleth in Powys.
Shrewsbury Town Council and Shropshire Wildlife Trust, which are working together on the project, say the beavers will boost biodiversity and help to combat flooding.
Speaking at a meeting of the town council’s new climate change committee, clerk Helen Ball said: “As an extinct but native species, beavers are integral to a part of Europe’s ecosystem.
“They are known as a ‘keystone species’, so they have the ability to engineer their surroundings and create niches for a high variety of other species, from plants and fungi to fish and birds.
“Studies have shown they filter pollution from the water, they can lock up carbon, they prevent flooding and they maintain nitrogen and other chemical cycles.”
Work on creating the enclosure and boardwalks on the 30-acre site is expected to start in November and be completed by June next year, with the beavers due to arrive between July and October 2022.
Veolia has committed £65,000 to the project, Severn Trent £64,000 and the town council £10,000.
Ms Ball told members it was likely more funding would need to be obtained, but that exact figures would not be known until tenders had been received for the work and a contractor appointed.
In a report to the committee, Ms Ball said: “There is significant work required to the site to make it suitable for containing beavers.
“The old and defunct post-wire fencing around the perimeter of the site has mostly been removed by our staff and volunteers in recent months.
“This needs replacing with beaver-proof fencing.
“This is a similar height to stock fencing with a backward turned ground skirt of mesh to prevent digging, and an angled top to discourage climbing.
“The total length of this is around two kilometres. Various access gates and culvert guards are required along this.
“We are also proposing a boardwalk along the southern section of the site, to allow easier fence inspections and to create an accessible public circular route around the whole perimeter.
“The ground conditions and limited access mean that this is a specialist job.”
The town council is inviting tenders for the construction of the enclosure until August 6.