The volunteer-only Katherine Junior Rugby League has been told to pay more than $500 to Katherine Town Council for the use of their own storage shed.

The league secured a NT Government Community Benefit Grant of almost $90,000 to build the multi-purpose shed at the Town Oval.

They then set about hiring contractors and negotiating with the council to build the shed, which is designed to help other community sporting groups wanting secure storage, at the sportsground.

But when treasurer of the junior sport group, Annette Schefe, passed over the keys to the Katherine Town Council for the finished project she said she was informed she would be charged the same as other sporting groups.

"We are a local community group who have gone to the trouble of building it.

"We went and did all the work, organised the builders, put in the plans, collected support letters and quotes.

"I was under the impression we'd be able to use it free of charge.

"It is pretty rough."

Construction of the new five bay shed was completed earlier this year to handle the increasing amount of sport groups using the oval.

Space was tight at the Don Dale Pavilion with many of the sporting groups needing space to store their equipment.

Despite plans to upgrade the pavilion with the $4.4 million NT Government investment, announced last year in July, Mrs Schefe said the council agreed to the extra building.

KTC has awarded a national firm of architects almost $300,000 to design the Sportsground upgrades.

Hames Sharley Architects will "deliver the design of a new sports pavilion facility between the existing ovals, safety enhancements to the entry road infrastructure, landscaping and parking improvements".

"I had a verbal agreement with council that we would build the shed and get to use it," Mrs Schefe said.

Run solely on volunteers, Katherine Junior Rugby League will now have to come up with just over $500 to store their sporting goods in one of the bays, and they want to use two.

"[The council] didn't have storage facilities for us to use," Mrs Schefe said.

"We don't charge a huge amount for our players to play.

"And now we will have to put all this money away from raffles and canteen sales to hire the shed we built.

"We are a small little league, we can't afford it."

According to a KTC spokeswoman, "the additional shed was identified from the user groups as a need and is complimentary to the ($4.4M) upgrade.

"It was identified that this was needed as the Sportsground has such large usage, especially after the closure of the Sports and Rec Club with all of the rugby union, rugby league and touch users now at the Sportsground."

She said the construction of the storage shed was with "strong support from the KTC Sportsground Advisory Group".

"By agreement with KTC and Katherine Junior Rugby League, KJR have two storage bays (generally restricted to one per club) and only one storage bay has been incorporated into the hire costs because of the grant.

"This facility is multi-purpose and is now directly benefiting four separate community sporting groups.

"Use of the storage bays is incorporated into the overall season hire of the facility by each sporting group which also include; ablutions, canteen facilities, further storage, field usage, office facilities and change rooms.

"Charges for community groups/non-for profits of the council facilities are on a user contributes basis which ensures affordable access to as many community groups as possible."

To celebrate the official opening of the new shed, Katherine Junior Rugby League will be playing their first round on April 28.

Kick off is at 8.30am, with the official opening at 9.30am.

For more information about the event, head to their Facebook page.