City presents new water-supply dashboard as drought threatens western reservoirs

Corpus Christi city officials on Tuesday unveiled a new public "water-supply dashboard" designed to show in one place how the city's raw and treated water supplies and demands interact amid an ongoing, multi-year drought.

The dashboard—presented by Corpus Christi Water Chief Operating Officer Drew Molly and hydrology consultant Michael Pinkney of Corollo Engineers—combines reservoir levels, inflows, Mary Rhodes Pipeline deliveries and expected new groundwater well output to project when the city's Western supplies would fall to drought thresholds. Molly said the tool answers community questions such as "When could we run out of water? When will our demands not meet supplies?" and shows the assumptions behind those answers.

Why it matters: Corpus Christi draws from both Western supplies (Choke Canyon and Lake Corpus Christi) and Eastern supplies delivered by the Mary Rhodes Pipeline from the Colorado River/Lake Texana system. With very low inflows into the Nueces watershed, the city faces a scenario in which Western reservoir percentages decline to levels that trigger higher stages of drought restrictions. The dashboard gives officials and the public a clearer, single-source view of that timeline and how new measures—pipeline operations, groundwater wells, or an unusually wet year—would change it.

The presentation and discussion

Molly said the dashboard uses the city's daily lake and delivery accounting, augmented this year to reflect potential future supplies and changing weather, and that he and staff have been working with the National Weather Service and the state climatologist to set realistic forecast windows. Corollo's Pinkney walked council through USGS streamflow data showing long-term declines in watershed inflows: "From 02/2008 to present, you have spent nearly every single year receiving less water than what has been in the historical average," Pinkney said, adding that some gauges now record flows at a fraction of earlier averages.

City staff showed March 2025 usage figures: roughly 96.2 million gallons per day total raw and treated water for the month, with about 59% of raw water supplied from the Mary Rhodes Pipeline, 35% from the Nueces River and the balance from Lake Corpus Christi for that month. Molly emphasized the pipeline's role: schedule 4 pumping is modeled at about 70–79 million gallons per day and that pipeline reliability is a central assumption in projections.

Key takeaways and clarifying details

- Current drought status: Large portions of the Nueces watershed and much of Texas remain in drought; some parts of the watershed have reached "extreme" or "exceptional" drought designations. - Historic inflows: Corollo showed that recent decades have delivered markedly lower annual inflows compared with a 1980–2009 baseline; some recent years rank in the lowest deciles of the 45‑year record. - Dashboard projections: The dashboard, using conservative low‑inflow assumptions based on 2024 hydrology, projects the Western supply hitting 15% in May (year referenced in the briefing), 10% later in the calendar year and shows an illustration that the next regulatory step—defined by staff as when demand exceeds supply (a Level 1 emergency)—occurs under the current assumptions in October 2026. Molly said the model is sensitive to rain: "If we have even just average rain, this next year, it is gonna drastically improve what this model is showing us today." - Additional supplies modeled: city staff included staged groundwater well output from Nueces County wells (modeled additions of ~3 million gallons per day in June 2025, another 3 MGD in September 2025 and a further 3 MGD in November 2025) and the full Mary Rhodes Pipeline schedule‑4 pumping. The model does not yet include all potential new supply options under evaluation. - Water-use snapshot: March 2025 total raw + treated water use was shown at about 96.22 MGD, with approximately 85 MGD treated at Owen Stevens WTP (numbers presented as monthly averages in the briefing).

Questions, concerns and next steps

Council members pressed staff for clarity and public messaging. Councilwoman Kalyn Paxton asked how the dashboard can present a quick snapshot (e.g., a single percentage for available supply) while still allowing drill‑downs; Molly and the city manager said staff would add callouts that quantify how much time new supplies (Mary Rhodes Phase 4, the modeled wells) buy and update daily text summaries sent to the council. Councilman Mark Scott asked for the inflow graphics to be re‑presented for the public; Pinkney and staff noted the USGS streamflow plots would be incorporated and that USGS had repaired a temporary gauge issue earlier in the month.

Several council members urged expanded public communication in plain English (and Spanish) and weekly updates while the city continues to add short‑term supplies and negotiate longer‑term options such as desalination or purchased interruptible supplies. City staff said they will revise the daily email to include dashboard highlights and will add Spanish translations to public materials.

Discussion vs. direction vs. decision

- Discussion: The council heard the data, model assumptions and alternatives; consultants described watershed inflow declines and the sensitivity of projections to rain and operational changes. - Direction: Staff was asked to add clearer callouts to the dashboard that show the effect of individual supply measures (for example: "with MRP schedule 4 and modeled wells, Level 1 is delayed by X days"), provide Spanish translations, incorporate USGS daily flows and revise daily council text summaries to include dashboard highlights. - Formal decision: None taken at the briefing; no regulatory restrictions were enacted at the meeting.

Speakers (selected)

- Drew Molly, Chief Operating Officer, Corpus Christi Water (city government). First referenced: 2025-04-15T09:20:22 (approx). Role: presented the dashboard, answered questions about modeling assumptions and pipeline operations. - Michael Pinkney, Corollo Engineers (consultant). First referenced: 2025-04-15T10:01:35 (approx). Role: presented watershed and streamflow analyses and percentile context for recent inflows. - Peter Zanoni, City Manager (city government). First referenced: 2025-04-15T08:01:30 (approx). Role: introduced the item and helped field council questions. - Councilmembers who asked substantive questions during the briefing: Kalyn Paxton (District 3), Eric Antu/Cantu (as listed in transcript), Mark Scott, Gil Hernandez, Sylvia Campos, Carolyn Vaughn, Everett Roy, Roland Barrera (titles: councilmembers; affiliation: city government). First references shown in transcript around 2025‑04‑15T12:47:00–14:00:00 (approx).

Clarifying details (structured)

- {"category":"monthly_usage","detail":"March 2025 total raw + treated water","value":96220000,"units":"gallons/day","approximate":false,"source_speaker":"Drew Molly"} - {"category":"mary_rhodes_pipeline","detail":"Modeled full schedule 4 pump capacity used in projections","value":"70-79","units":"million gallons/day","approximate":true,"source_speaker":"Drew Molly"} - {"category":"groundwater_phase_in","detail":"Modeled Nueces County groundwater additions","value":9,"units":"million gallons/day total (3 MGD phased in Jun, Sep, Nov 2025)","approximate":true,"source_speaker":"Drew Molly"} - {"category":"western_supply_thresholds","detail":"Projected dates per current assumptions","value":"15% in May, 10% in November; Level 1 (demand>supply) in Oct 2026","units":"percent / date","approximate":true,"source_speaker":"Drew Molly"}

Proper names

[{"name":"Mary Rhodes Pipeline","type":"other"},{"name":"Lake Corpus Christi","type":"location"},{"name":"Choke Canyon Reservoir","type":"location"},{"name":"Nueces River","type":"location"},{"name":"Corpus Christi Water","type":"agency"},{"name":"Owen Stevens Water Treatment Plant","type":"facility"},{"name":"Texas Commission on Environmental Quality","type":"agency"},{"name":"United States Geological Survey","type":"agency"},{"name":"National Weather Service","type":"agency"}]

Authorities

[{"type":"other","name":"United States Geological Survey (USGS) streamflow gauges","referenced_by":["water dashboard presentation"]},{"type":"other","name":"National Weather Service forecasts","referenced_by":["water dashboard presentation"]},{"type":"other","name":"Texas Commission on Environmental Quality (TCEQ) permitting and oversight","referenced_by":["discussion of groundwater well permitting and regulatory coordination"]},{"type":"policy","name":"City Drought Contingency Plan","referenced_by":["explanation of stages and triggers"]}]

Community relevance

- Geographies: Nueces River watershed, Choke Canyon, Lake Corpus Christi, Lavaca-Navidad watershed, Lake Texana, Mary Rhodes Pipeline service area. - Impact groups: all municipal water customers, industrial customers who rely on bulk water deliveries, partner wholesale customers (Alice, Beeville, Mathis, San Patricio MWD).

Meeting context

- Engagement level: extended briefing; multiple council members asked detailed technical and communications questions; the presentation prompted requests for additional public messaging and translations. - Implementation risk: medium — projections depend on pipeline operations, successful permitting and well development, and on rainfall. - History: staff has previously provided daily lake-level updates; the dashboard consolidates that information with modeled projections.

Searchable_tags:["water","drought","Mary_Rhodes_Pipeline","Choke_Canyon","groundwater","Corpus_Christi_Water","drought_dashboard"]

Provenance:{"transcript_segments":[{"block_id":"s:3514.6","local_start":0,"local_end":180,"evidence_excerpt":"Okay. Good morning, Mayor, council. I think it's still morning. Is it morning? What time is it? Okay. It's afternoon. Officially afternoon. Drew Molly, Chief Operating Officer for Corpus Christi Water. The purpose of today's briefing, is to provide you with an overview of the water supply dash weeks, as well as, provide some background information on the ongoing drought conditions for our Nueces River, watershed.","reason_code":"topicintro"},{"block_id":"s:8252.1045","local_start":0,"local_end":120,"evidence_excerpt":"So we'll follow-up on a few things. But other than that, Drew, thank you very much. And thank you to the team. I am going to, pass the consent agenda item.","reason_code":"topicfinish"}]},