(a) The Brazos River and its associated tributaries and bay and estuary system and the San Bernard River and its associated tributaries are healthy and sound ecological environments.(b) The commission finds that these sound ecological environments can best be maintained by a set of flow standards that implement a schedule of flow quantities that contain subsistence flow, base flow, and high flow pulses at defined measurement points. Minimum flow levels for these components will vary by season and by year since the amount of precipitation and, therefore, whether a system is in dry, average, or wet base flow conditions, will vary from year to year and within a year from season to season, and the number of pulses protected will also vary with the amount of precipitation and hydrologic conditions.