Okla. Stat. tit. 82, § 82-612

The board of directors may at any time, when necessary to

fulfill the objects for which the district was created alter or add

to the official plan, and when such alterations or additions are

formally approved by the board and by the court, and are filed with

the secretary, they shall become a part of the official plan, but

they shall neither materially modify the general character of the

work, nor materially increase resulting damages for which the board

is not able to make amicable settlement, nor increase the cost more

than ten per cent (10%), no action other than a resolution of the

Board of directors shall be necessary for the approval of such

alterations or additions. In case the proposed alterations or

additions materially modify the resulting damages or materially

reduce the benefits, for which the board is not able to make

amicable settlement, or materially increase the benefits in such a

manner as to require a new appraisal, or increase the cost more than

ten per cent (10%), the court shall direct the board of appraisers

(which may be the original board, or a new board appointed by the

court on petition of the board of directors or otherwise) to

appraise the property to be taken, benefited or damaged, by the

proposed alterations or additions. Upon the completion of the report

of the Board of appraisers, notice shall be given in the same manner

as in the case of the original report of the board of appraisers,

Oklahoma Statutes - Title 82. Waters and Water Rights Page 102

and the same right of appeal shall exist. Provided, that where few

land owners are affected, if found to be more economical and

convenient, personal notice of the pendency of the report of said

appraisers shall be given instead of notice by publication; and

provided, that if the only question at issue is additional damages

or reduction of benefits to property, due to modifications or

additions to the plans, the board of directors, may, if they find it

practicable, make settlements with the owners of the property

damaged instead of having appraisals made by the board of

appraisers. In case such settlements are made, notice and hearing

need not be had. After bonds have been sold, in order that their

security may not be impaired, no reduction shall be made in the

amount of benefits appraised against property in the district, but

in lieu of such reduction in benefits, if any are made, the amount

shall be paid to the party in cash. This provision shall apply to

all changes in appraisals under this act.