Mrs Baker-Hogan said the restructuring was expected to take place in the next few months.
She said the current administration would make way for a more streamlined operation "tasked with representing Wanganui's changing community needs and expectations".
She said Ms Timpany and her staff were helping the board work through the transition.
Meanwhile, the Wanganui office of Craigs Investment Partners has been appointed to provide investment advice to the foundation after a number of organisations were invited to tender for the role.
Mrs Baker-Hogan said a range of community stakeholders were involved in the review which looked at all the foundation's work including grants, investments and community initiatives that benefited individuals and groups each year. But she emphasised the core grants system and funding work of the foundation would not be changed.
"Under the Community Trust Act 1988, community organisations and other benefactors will continue to benefit from the foundation's support of charitable, cultural, philanthropic and recreational activities in the wider Wanganui area," Mrs Baker-Hogan said.
The Whanganui Community Foundation is one of 12 such trusts across the country, established after the Government restructured the trustee savings banks in 1988. It began as the Trust Bank Wanganui Community Trust but changed its name to Whanganui Community Foundation in 2000.
In 1994 and again two years later, the community trusts sold their shares and ended any relationship with the former trust bank. Proceeds from the sale of those shares were invested and continue to provide the income used by the foundation to make grants, provide professional development and other activities for the community.
The foundation's total equity (at March 31, 2013) was $35,179,881. That included $23 million invested through United States-based international investment company State Street Global Assets, $2.2 million in bonds and $7 million in term deposits.
Chester Borrows, MP for Whanganui, said he was pleased to see the foundation had carried out the review.
"I have been concerned about its performance for some time and members of the public have continually raised similar concerns with me."
Mr Borrows would not detail what those concerns were "but I'm keen to see what developments follow this review".
However, he said he did question why the foundation needed the administrative support it had when the Powerco Wanganui Trust, delivering significant grants, operated "with just a secretary" and a board.
Appointments to the foundation's board are made by the Associate Finance Minister Jonathan Coleman and Mr Borrows said previously he had put forward names of potential appointees, as did the Ministry for Women's Affairs and the board itself.
"But the Minister is the final arbiter in those appointments."
The foundation will make four funding rounds this year. In 2013 it made 150 grants totalling $973,000.
Grants are available for not-for-profit organisation in Wanganui, Waimarino, Rangitikei, Waverley and Patea districts.