(a) This section applies only to the watermaster with jurisdiction over the Rio Grande and the water division for which that watermaster is appointed.
(b) The watermaster shall divide the water of the streams or other sources of supply of the division in accordance with the adjudicated water rights.

(c) The watermaster shall regulate or cause to be regulated the controlling works of reservoirs and diversion works in time of water shortage, as is necessary because of the rights existing in the streams of the division, or as is necessary to prevent the waste of water or its diversion, taking, storage, or use in excess of the quantities to which the holders of water rights are lawfully entitled.
(d) The watermaster may regulate the distribution of water from any system of works that serves users whose rights have been separately determined.
(e) The watermaster’s duties do not include activities that relate to other programs of the commission, except as provided by this section. The watermaster’s duties shall include activities that relate to situations of imminent threat to public health and safety or the environment. The commission shall adopt rules:
(1) defining situations of imminent threat under this section; and
(2) addressing the watermaster’s duties in response to terrorism.
(f) The watermaster may store in a reservoir for release at a later time water in transit that is being conveyed down the banks and bed of the Rio Grande under a permit issued by the commission and in accordance with rules prescribed by the commission. In this section, “water in transit” means privately owned water, not including state water, that a person has pumped from an underground reservoir and that is in transit between the point of discharge into the river and the place of use or the point of diversion by a person who has contracted with the owner of the water to purchase the water. The contract must specify that the contract is for the purchase and delivery of a specified amount of water less the carriage losses incurred in transit, as described and measured according to commission rules.
(g) The watermaster may store water under Subsection (f) only if the storage does not hinder the ability of any other holders of Rio Grande surface water rights to store the maximum authorized capacity in a reservoir as specified by commission rules and relevant permits, certified filings, or certificates of adjudication.
(h) Before granting a permit to convey water down the banks and bed of the Rio Grande, the commission shall adopt rules that provide for the methods and procedures by which the watermaster shall account for any discharge, delivery, conveyance, storage, diversion, or associated loss of water conveyed down the banks and bed of the Rio Grande. A permit to convey water down the banks and bed of the Rio Grande may not allow the permit holder to share in any beneficial state water inflows into the Rio Grande. The permit holder is entitled to convey only the amount of water specified in the permit, less the carriage losses incurred in transit, as described and measured according to commission rules. A rule adopted by the commission under this subsection must be consistent with the Treaty Relating to the Utilization of the Waters of the Colorado and Tijuana Rivers, and of the Rio Grande (Rio Bravo) from Fort Quitman, Texas, to the Gulf of Mexico, concluded by the United States and the United Mexican States on February 3, 1944, and with any minute order adopted by the International Boundary and Water Commission.
(i) In considering an application for a permit to convey water down the banks and bed of the Rio Grande, the commission shall consider the quality of the water to be conveyed. The commission may not issue a permit if it determines that the water to be conveyed would degrade the water quality of the Rio Grande.