GCWA - Firm Yield & Water Rights Analysis

Beginning in 2010, Jordan Furnans has worked with the Gulf Coast Water Authority (GCWA) to manage its water rights and maximize water delivery and availability to customers. Initial efforts involved using the WAM to quantify GCWA’s run-of-river firm yield from its 3 Brazos River water rights (with 6 total priority dates), and to compare this yield against contract commitments. Additional efforts included adding “contract water” from the BRA into GCWA’s water portfolio and quantifying how much extra water is needed to meet customer needs during severe droughts. This required refinement of the Brazos WAM, and ultimately development of the Daily-Hydro model for GCWA, which allowed for WAM-style water availability assessments on a daily/operational basis using streamgauge records rather than naturalized flows (which were only accepted through 1999 and did not include the severe, controlling drought of 2011.). Jordan also performed WAM modeling to demonstrate to GCWA the benefits of the BRA systems-operation permit, and how it could result in increased water reliability for GCWA (through additional contract water purchases. This analysis also included assessments of yields of Allens Creek Reservoir, Gibbons Creek Reservoir, Cedar Ridge Reservoir, and other un-named potential reservoirs located upstream of GCWA within the Brazos River Basin. Modeling was performed to assess these potential reservoir yields with and without inclusion in the BRA’s systems-operations modeling framework. Current GCWA efforts include permit amendments, accounting plan development, and watershed modeling to assess how watermaster operations have enhanced or hindered GCWA yields. LRE Water is also actively monitoring basin conditions to aid water operation decisions by GCWA, subject to its adopted drought contingency plan.