(a) The commission by rule shall exempt the projects listed in Subsection (b) from any permit requirement or payment to the department for materials removed if the commission finds that the state will not be deprived of significant revenue and there will be no significant adverse effects on navigation, the coastal sediment budget, riverine hydrology, erosion, or fish and wildlife resources or their habitat.
(b) Projects that may be exempted under Subsection (a) include:
(1) projects resulting in insignificant takings or disturbances of marl, sand, gravel, shell, or mudshell;
(2) projects to restore or maintain the storage capacity of existing public water supplies;
(3) maintenance projects carried out by public utilities for noncommercial purposes; and
(4) public road projects contracted by the Texas Department of Transportation.

(b-1) In this subsection, “unconsolidated sedimentary material” means loose gravel, sand, or other sedimentary material that has been transported by the flow of the watercourse. The term does not include solid bedrock or earthen banks. A project results in an insignificant taking or disturbance of marl, sand, gravel, shell, or mudshell for purposes of Subsection (b)(1) if:
(1) the project is noncommercial;
(2) the project takes or disturbs less than 125 cubic yards of dry unconsolidated sedimentary material within a 12-month period;
(3) the project occurs within an on-channel impoundment created by a dam originally constructed on or before December 31, 1955, and the dam crest has not been increased in height by more than six inches since initial construction; and
(4) the taking or disturbance of unconsolidated sedimentary material does not occur outside of the impoundment in areas above dam crest elevation.
(c) The commission may require the performance of scientific studies as needed to determine the cumulative effect of permitted operations in a watershed on natural resources using the criteria described by Section 86.004 and may provide for permit holders to participate in the performance of those studies. The commission may reimburse a participating permit holder for costs incurred by the permit holder in performing the study in an amount equal to not more than one-fourth of all royalty fees paid by the permit holder to the commission. Total reimbursements to all participating permit holders may not exceed one-half the total cost of the study.