<xs:simpleType name="impFlow"> <xs:restriction base="xs:string"> <xs:enumeration value="US_gallonPerDay" /> <xs:enumeration value="IMP_gallonPerDay" /> <xs:enumeration value="cubicFeetDay" /> <xs:enumeration value="US_gallonPerMinute" /> <xs:enumeration value="IMP_gallonPerMinute" /> <xs:enumeration value="acreFeetDay" /> <xs:enumeration value="cubicFeetSecond" /> </xs:restriction> </xs:simpleType>