Claims and encumbrances limited by amount and purpose of allotment. The agency shall not create any claim or encumbrance for the future disbursement of appropriated moneys unless the proposed expenditure as estimated, together with expenses theretofore paid from or encumbered against such allotment, is within the total amount and for the purposes specified in the notice of allotment transmitted to such agency

ORS 291.250 — under Chapter 291.