Article

Climate and Water Monitoring at Big Bend National Park: Water Year 2022

Big Bend National Park

Fluffy clouds and patches of sun on rugged desert mountains and hills.
Big Bend National Park

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Overview

Together, climate and hydrology shape ecosystems and the services they provide, particularly in arid and semi-arid ecosystems. Understanding changes in climate, groundwater, and surface water is key to assessing the condition of park natural resources—and often, cultural resources.

At Big Bend National Park (Figure 1), Chihuahuan Desert Inventory and Monitoring Network scientists study how ecosystems may be changing by taking measurements of key resources, or “vital signs,” year after year—much as a doctor keeps track of a patient’s vital signs. This long-term ecological monitoring provides early warning of potential problems, allowing managers to mitigate them before they become worse. At Big Bend National Park, we monitor climate, groundwater, and springs, among other vital signs.

Surface water and groundwater conditions are closely related to climate conditions. Because they are better understood together, we report on climate in conjunction with water resources. Reporting is by water year (WY), which begins in October of the previous calendar year and goes through September of the water year (e.g., WY2022 runs from October 2021 through September 2022). This article reports the results of climate and water monitoring at Big Bend National Park (Figure 1) in WY2022.

Map of Big Bend National Park showing 5 weather stations throughout the park.
Figure 1. Monitored weather stations at Big Bend National Park.

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Climate and Weather

There is often confusion over the terms “weather” and “climate.” In short, weather describes instantaneous meteorological conditions (e.g., it’s currently raining or snowing, it’s a hot or frigid day). Climate reflects patterns of weather at a given place over longer periods of time (seasons to years). Climate is the primary driver of ecological processes on earth. Climate and weather information provide context for understanding the status or condition of other park resources.

Methods

We report on five National Oceanic and Atmospheric Administration Cooperative Observer Program (NOAA COOP) weather stations at Big Bend National Park (Figure 1):

  • Chisos Basin (#411715) at an elevation of 5,300 ft (1,615 m), operational since 1943;
  • Panther Junction (#416792) at an elevation of 3,740 ft (1,140 m), operational since 1955;
  • Persimmon Gap (#416959) at an elevation of 2,870 ft (875 m), operational since 1952;
  • Castolon (#411524) at an elevation of 2,170 ft (661 m), operational since 1947; and
  • Rio Grande Village Texas (#417624) at an elevation of 1,857 ft (566 m), operational since 2006.
These stations provide reliable, long-term climate datasets used for analyses in this climate and water report. The long-term averages used for comparison in this report are from NOAA and are based on 1991–2020 data. The exception is the Rio Grand Village Texas station, where we use long-term averages from the period of record for this station (2006–2020). Data from these stations are accessible through Climate Analyzer.
Storms and a rainbow above a desert valley with mountains in the background.
Storms over Big Bend National Park

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Results for Water Year 2022

For precipitation and temperature monitoring results, scroll down or click on a weather station here:

Chisos Basin (COOP) ǀ Panther Junction (COOP) ǀ Persimmon Gap (COOP) ǀ Castalon (COOP) ǀ Rio Grande Village Texas (COOP)

Jump to drought index monitoring results.

Precipitation and Air Temperature—Chisos Basin

Annual precipitation at Chisos Basin in WY2022 was 10.76″ (27.3 cm; Figure 2), 7.57″ (19.2 cm) less than the 1991–2020 average. Only June and September had rainfall totals greater than the 1991–2020 averages. Rainfall amounts in all other months were less than average, with no rain occurring in January, March, and April. Extreme daily rainfall events
(≥ 1″; 2.54 cm) occurred on 2 days, half the 1991–2020 average annual frequency of 4 days. Extreme rainfall events occurred on 01 June 2022 (1.00″; 2.5 cm) and 15 June 2022 (1.05″; 2.7 cm).

The mean annual maximum temperature at Chisos Basin in WY2022 was 75.6°F (24.2°C), 2.1°F (1.2°C) above the 1991–2020 average. The mean annual minimum temperature in WY2022 was 53.9°F (12.2°C), 1.6°F (0.9°C) above the 1991–2020 average. Mean monthly maximum and minimum temperatures in WY2022 were warmer than the 1991–2020 monthly averages for eight months of the year, differing by as much as 10.2°F (5.7°C; see December as an example) relative to the 1991–2020 monthly averages (Figure 2). Substantially cooler than average temperatures only occurred in February. Extremely hot temperatures (≥ 90°F; 32.2°C) occurred on 47 days in WY2022, over twice the 1991–2020 average frequency of 22.1 days. Extremely cold temperatures (≤ 30°F; −1.1°C) occurred on 21 days, slightly more than the average frequency of 18.9 days.

Bar and line graph showing monthly precipitation totals in water year 2022 are lower than the long-term average in all months except June and September. Max and min temperatures for water year 2022 were above or similar to average most of the year.
Figure 2. Climogram showing monthly precipitation and mean maximum and minimum air temperatures in water year 2022 (WY2022) and the 1991–2020 averages at Chisos Basin weather station, Big Bend National Park. Data Source: climateanalyzer.org.

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Precipitation and Temperature—Panther Junction

Annual precipitation at Panther Junction in WY2022 was 8.69″ (22.1 cm; Figure 3), 4.31″ (10.9 cm) less than the 1991–2020 annual average. Rainfall totals in December, February, June, August, and September of WY2022 were similar to the 1991–2020 monthly averages. Rainfall totals in all other months were less than average, with no rain occurring in March and April. Extreme daily rainfall events (≥ 1″; 2.54 cm) occurred on 2 days, similar to the 1991–2020 average annual frequency of 2.5 days. Extreme rainfall events occurred on 09 June 2022 (1.01″; 2.6 cm) and 05 July 2022 (1.10″; 2.8 cm).

The mean annual maximum temperature at Panther Junction in WY2022 was 82.7°F (28.2°C), 4.0°F (2.2°C) above the 1991–2020 average. The mean annual minimum temperature in WY2022 was 56.6°F (13.7°C), 2.5°F (1.4°C) above the 1991–2020 average. Mean monthly maximum and minimum temperatures in WY2022 were generally warmer than or near average for most of the year and differed by as much as 12.9°F (7.2°C; see December as an example) relative to the 1991–2020 monthly averages (Figure 3). Substantially cooler than average temperatures only occurred in February. Extremely hot temperatures (≥ 98°F; 36.7°C) occurred on 43 days in WY2022, substantially more than the 1991–2020 average frequency of 25 days. Extremely cold temperatures (≤ 31°F; −0.6°C) occurred on 20 days, slightly less than the average frequency of 22.1 days.

bar and line graph showing monthly precipitation totals in water year 2022 are lower than the long-term averages in all months except December, June, August, and September. Max and min temperatures were above or similar to average for most of the year.
Figure 3. Climogram showing monthly precipitation and mean maximum and minimum air temperatures in water year 2022 (WY2022) and the 1991–2020 averages at Panther Junction weather station, Big Bend National Park. Data Source: climateanalyzer.org.

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Precipitation and Air Temperature—Persimmon Gap

Annual precipitation at Persimmon Gap in WY2022 was 9.23″ (23.4 cm; Figure 4), 1.62″ (4.1 cm) less than the 1991–2020 annual average. Rainfall totals in February, June, August, and September were 30–146% greater than the 1991–2020 monthly averages. December rainfall was similar to the 1991–2020 average. Rainfall totals in all other months were less than average, with no rain occurring in January, March, and April. Extreme daily rainfall events (≥ 1″; 2.54 cm) occurred on 1 day, less than the 1991–2020 average annual frequency of 2.4 days. A single extreme rainfall event occurred on 02 June 2022 (1.92″; 4.9 cm).

The mean annual maximum temperature at Persimmon Gap in WY2022 was 85.6°F (29.8°C), 2.6°F (1.4°C) above the 1991–2020 average. The mean annual minimum temperature in WY2022 was 54.7°F (12.6°C), 1.1°F (0.6°C) above the 1991–2020 average. Mean monthly maximum and minimum temperatures in WY2022 were generally warmer than or near average for most of the year and differed by as much as 11.6°F (6.4°C; see December as an example) relative to the 1991–2020 monthly averages (Figure 4). However, substantially cooler than average temperatures occurred in February. Extremely hot temperatures (≥ 103°F; 39.4°C) occurred on 31 days in WY2022, more than the 1991–2020 average frequency of 22.2 days. Extremely cold temperatures (≤ 28°F; −2.2°C) occurred on 21 days, more than the average frequency of 16.6 days.

Bar and line graph showing monthly precipitation totals in water year 2022 are lower than the long-term averages in all months except February, June, August, and September. Max and min temperatures were above or similar to averages for most of the year.
Figure 4. Climogram showing monthly precipitation and mean maximum and minimum air temperatures in water year 2022 (WY2022) and the 1991–2020 averages at Persimmon Gap weather station, Big Bend National Park. Data Source: climateanalyzer.org.

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Precipitation and Air Temperature—Castolon

Annual precipitation at Castolon in WY2022 was 7.20″ (18.3 cm; Figure 5), 2.66″ (6.8 cm) less than the 1991–2020 average. Rainfall totals in June and August were 40% and 69% greater than the 1991–2020 averages, respectively. Rainfall totals in October and September were similar to averages. Rainfall totals in all other months were less than average, with no rain occurring in December, January, March, and April. Extreme daily rainfall events (≥ 1″; 2.54 cm) occurred on 3 days, more than the 1991–2020 average annual frequency of 2.1 days. Extreme rainfall events occurred on 01 June 2022 (1.55″; 3.9 cm), 18 August 2022 (1.32″; 3.4 cm), and 01 September 2022 (1.23″; 3.1 cm).

The mean annual maximum temperature at Castolon in WY2022 was 88.7°F (31.5°C), 0.4°F (0.2°C) above the 1991–2020 average. The mean annual minimum temperature in WY2022 was 58.2°F (14.6°C), 1.0°F (0.6°C) above the 1991–2020 average. Mean monthly maximum and minimum temperatures in WY2022 were generally warmer than average and differed by as much as 8.8°F (4.9°C; see December as an example) relative to the 1991–2020 averages, but temperatures during several months were near average or substantially cooler (Figure 5). Substantially cooler than average temperatures occurred in February. Extremely hot temperatures (≥ 108°F; 42.2°C) occurred on 22 days in WY2022, slightly less than the 1991–2020 average frequency of 24.7 days. Extremely cold temperatures (≤ 30°F; −1.1°C) occurred on 13 days, less than the average frequency of 18.7 days.

Bar and line graph showing monthly precipitation totals in water year 2022 are lower than the long-term averages in all months except October, June, and August. Max and min temperatures were above or similar to averages for most of the year.
Figure 5. Climogram showing monthly precipitation and mean maximum and minimum air temperatures in water year 2022 (WY2022) and the 1991–2020 averages at Castolon weather station, Big Bend National Park. Data Source: climateanalyzer.org.

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Precipitation and Air Temperature—Rio Grande Village Texas

Annual precipitation at Rio Grande Village Texas in WY2022 was 6.30″ (16.0 cm; Figure 6), 5.76″ (14.6 cm) less than the 2006–2020 average. Rainfall in November was 2.08″ (5.3 cm), four times the 2006–2020 average. Rainfall totals in October and February were similar to average. Rainfall totals in all other months were less than average, with no rain occurring in January, March, and April. Extreme daily rainfall events (≥ 1″; 2.54 cm) occurred on 2 days, similar to the 2006–2020 average annual frequency of 1.5 days. Extreme rainfall events occurred on 22 October 2021 (1.09″; 2.8 cm) and 28 November 2021 (2.05″; 5.2 cm).

The mean annual maximum temperature at Rio Grande Village Texas in WY2022 was 91.9°F (33.3°C), 2.4°F (1.3°C) above the 2006–2020 average. The mean annual minimum temperature in WY2022 was 54.7°F (12.6°C), 0.2°F (0.1°C) above the 2006–2020 average. Mean monthly maximum temperatures in WY2022 were generally warmer than average for most of the year and differed by as much as 11.4°F (6.3°C; see December as an example) relative to the 2006–2020 monthly averages (Figure 6). Mean monthly minimum temperatures were more variable relative to average. Extremely hot temperatures (≥ 109°F; 42.8°C) occurred on 48 days in WY2022, much more than the 2006–2020 average frequency of 30 days. Extremely cold temperatures (≤ 26°F; −3.3°C) occurred on 26 days, slightly more than the average frequency of 24.3 days.

bar and line graph showing monthly precipitation totals in water year 2022 are lower than the long-term averages in all months except October, November, and February. Max and min temperatures were above or similar to averages for most of the year.
Figure 6. Climogram showing monthly precipitation and mean maximum and minimum air temperatures in water year 2022 (WY2022) and the 2006–2020 averages at Rio Grande Village Texas weather station, Big Bend National Park. Data Source: climateanalyzer.org.

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Drought

Reconnaissance drought index (Tsakiris and Vangelis 2005) provides a measure of drought severity and extent relative to the long-term climate. It is based on the ratio of average precipitation to average potential evapotranspiration (the amount of water loss that would occur from evaporation and plant transpiration if the water supply was unlimited) over short periods of time (seasons to years). The reconnaissance drought indices for all five weather stations at Big Bend National Park indicate that WY2022 was drier than the long-term averages from the perspective of both precipitation and potential evapotranspiration (Figure 7, Chisos Basin station; Figure 8, Panther Junction station; Figure 9, Persimmon Gap station; Figure 10, Castolon station; Figure 11, Rio Grande Village Texas station).

Reference: Tsakiris G., and H. Vangelis. 2005. Establishing a drought index incorporating evapotranspiration. European Water 9: 3–11.

Bar graph showing that water year 2022 is drier than the long-term average and the drought index was quite variable over the years.
Figure 7. Reconnaissance drought index for Chisos Basin weather station in water years 1991–2022, Big Bend National Park. Drought index calculations are relative to the time period selected (1990–2022). Choosing a different set of start/end points may produce different results. “N/Aˮ = insufficient data to generate reliable estimates. Data source: climateanalyzer.org.

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Bar graph showing that water years 2020 through 2022 were drier than the long-term average.
Figure 8. Reconnaissance drought index for Panther Junction weather station in water years 1991–2022, Big Bend National Park. Drought index calculations are relative to the time period selected (1990–2022). Choosing a different set of start/end points may produce different results. “N/Aˮ = insufficient data to generate reliable estimates. Data source: climateanalyzer.org.

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Bar graph showing water years 2020 through 2022 were drier than the long-term average.
Figure 9. Reconnaissance drought index for Persimmon Gap station in water years 1991–2022, Big Bend National Park. Drought index calculations are relative to the time period selected (1990–2022). Choosing a different set of start/end points may produce different results. “N/Aˮ = insufficient data to generate reliable estimates. Data source: climateanalyzer.org.

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Bar graph showing water years 2020 through 2022 are drier than the long-term average.
Figure 10. Reconnaissance drought index for Castolon station in water years 1991–2022, Big Bend National Park. Drought index calculations are relative to the time period selected (1990–2022). Choosing a different set of start/end points may produce different results. “N/Aˮ = insufficient data to generate reliable estimates. Data source: climateanalyzer.org.

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Bar graph showing water years 2020 through 2022 are drier than the long-term average.
Figure 11. Reconnaissance drought index for Rio Grande Village Texas weather station in water years 2006–2022, Big Bend National Park. Drought index calculations are relative to the time period selected (1990–2022; note there are no drought data for this station prior to 2006). Choosing a different set of start/end points may produce different results. “N/Aˮ = insufficient data to generate reliable estimates. Data source: climateanalyzer.org.

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Groundwater 

Groundwater is one of the most critical natural resources of the American Southwest, providing drinking water, irrigating crops, and sustaining rivers, streams, and springs throughout the region.  

Groundwater results for WY2022 are not currently available. We will report results when the data are acquired and processed.

Springs

Background

Springs, seeps, and tinajas (small pools in a rock basin or impoundments in bedrock) are small, relatively rare biodiversity hotspots in arid lands. They are the primary connection between groundwater and surface water and are important water sources for plants and animals. For springs, the most important questions we ask are about persistence (How long was there water in the spring?) and water quantity (How much water was in the spring?). Springs reporting is by water year (WY), which begins in October of the previous calendar year and goes through September of the current calendar year (e.g., WY2022 runs from October 2021 through September 2022). Springs sampling for WY2022 at Big Bend National Park occurred between 06 February and 04 March 2022, except for water persistence, which is monitored continuously throughout the water year.

List of Springs

Scroll down or click on a spring below to view monitoring results.

Bois D'Arc Spring ǀ Cattail Falls ǀ Chilicotal Spring Complex ǀ De La Ho Spring ǀ Government Spring ǀ Grapevine Spring ǀ Lorn Spring ǀ Lower Croton Spring ǀ Mule Ears Spring ǀ Painted Hills Spring ǀ Peña Spring 1 ǀ Red Ass Spring ǀ Rough Spring B ǀ Screwbean Spring ǀ Shelf Spring ǀ Solis Spring ǀ Tiptoe Spring ǀ Water Boy Tinaja

A person pointing at a dry depression filled with soil and dried plants next to bedrock in a drainage.
Figure 12. Bois D'Arc Spring at Big Bend National Park, February 2022.

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WY2022 Findings at Bois D'Arc Spring

Bois D’Arc Spring (Figure 12 above) is a rheocrene spring (a spring that emerges into one or more stream channels) located within a bedrock canyon on the north side of the Chisos Mountains. When the WY2022 visit occurred on 17 February 2022, the spring was dry. In previous years, the spring formed an intermittently wetted (contained water) channel that was up to 40 m in length.

Site Condition

In WY2022, Bois D’Arc Spring was highly disturbed by drying (the spring was completely dry; rated undisturbed to highly disturbed in the past). We rated the spring slightly disturbed by wildlife (scat and tracks; rated undisturbed to moderately disturbed in the past). No other natural or human-caused disturbances were observed at Bois D'Arc Spring in WY2022.

We did not observe invasive aquatic animals (e.g., crayfish or American bullfrogs [Lithobates catesbeianus]) in WY2022. Similar to prior visits, we detected the invasive, perennial Lehmann lovegrass (Eragrostis lehmanniana) in evenly distributed patches. This grass was slightly denser than in prior visits. Despite drying, we observed sedges (Cyperaceae) and rushes (Juncaceae) around previously wetted areas, but monkey flower (Mimulus sp.), observed in wetted years, was not present.

Water Quantity

Water persistence data are missing for WY2022 due to a temperature sensor battery malfunction in July 2021. A new sensor was deployed during the February 2022 visit. In prior water years, the spring was wetted 6.2–88.5% of the days measured (Figure 13).

Area chart showing that the spring has had dry periods in summer and fall since 2018 and missing data periodically including all of water years 2017 and 2022 and half of 2018.
Figure 13. Water persistence in Bois D'Arc Spring, Big Bend National Park.

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Discharge and wetted extent were not measurable in WY2022 because the spring was dry during our visit.

Water Quality

Core water quality and water chemistry data could not be collected in WY2022 since the spring was dry.

Figure 14. A large pool of water at the base of a steep rock wall where water flows into the pool. Water flows from the pool out of sight.
Figure 14. Cattail Falls at Big Bend National Park, February 2022.

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WY2022 Findings at Cattail Falls

Cattail Falls (Figure 14 above) is a rheocrene spring (a spring that emerges into one or more stream channels) located in Cattail Canyon on the northwest side of the Chisos Mountains. The WY2022 visit occurred on 18 February 2022, and the spring was wetted (contained water) at the time of sampling. The spring begins high in the mountains and flows over a steep pouroff into a wide pool. A channel flows out of the pool and continues for approximately 100 m, forming plunge pools surrounded by boulders and dense vegetation.

Site Condition

In WY2022, Cattail Falls was slightly disturbed by flow modification (a diversion pipe leading down and away from the stream; rated undisturbed to slightly disturbed in the past), slightly disturbed by wildlife (tracks and browsing; rated undisturbed to slightly disturbed in the past), slightly disturbed by windthrow (downed trees; rated undisturbed to moderately disturbed in the past), moderately disturbed by hiking trails (popular trail leading to the spring; rated moderately to highly disturbed in the past), and moderately disturbed by contemporary human use (trampling and heavy trail use; rated moderately to highly disturbed in the past). No other natural or human-caused disturbances were observed at Cattail Falls in WY2022.

We did not observe invasive aquatic animals (e.g., crayfish or American bullfrogs [Lithobates catesbeianus]) and no invasive plants at Cattail Falls in WY2022. As in prior years, we observed the following obligate/facultative wetland plants: bluestem (Andropogon sp.), cattails (Typhaceae), maidenhair fern (Adiantum sp.), rushes (Juncaceae), sedges (Cyperaceae), and spikerush (Eleocharis sp.).

Water Quantity

The temperature sensor indicated that Cattail Falls was wetted for 141 of 141 days measured (100% of days) up to the WY2022 visit (Figure 15). In prior water years, the spring was wetted 96.3–100% of the days measured.

Area chart showing that Cattail Falls has year-round water persistence with one period of dryness in August 2018 and missing data from April 2020 to April 2021.
Figure 15. Water persistence in Cattail Falls, Big Bend National Park.

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We estimated discharge at 40.4 ± 1.5 L/min (10.7 ± 0.4 gal/min) in WY2022 (Table 1). When compared with prior years, WY2022 discharge was within the range of prior values (40.1–72.1 L/min; 2018–2021), but near the low end of the range.

Wetted extent was evaluated using a method for flowing water. The total brook length was 95.6 m (313.6 ft). Width and depth averaged 3.0 m (9.8 ft) and 6.1 cm (2.4 in), respectively (Table 2). Length was within the range of 2018–2021 values, while width and depth were slightly lower in WY2022.

Water Quality

Core water quality (Table 3) data were collected at the primary sampling location on the edge of the main pool at the base of the falls. Dissolved oxygen, temperature, and pH were lower than in previous years, total dissolved solids were within the range of prior samples, and specific conductivity was higher than previously observed. Core water chemistry data (Table 4) were also collected at the primary sampling location. Chloride, magnesium, and potassium were within the range of prior values, while alkalinity, calcium, and sulphate were slightly higher than in previous years. The results are presented in the following tables along with ranges of prior values (2018–2021).

Cattail Falls Data Tables

A cross-view of a scoured drainage containing a spring complex and the intermittently wetted channel in a hilly area with desert shrubs..
Figure 16. Chilicotal Spring Complex at Big Bend National Park, February 2022.

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WY2022 Findings at Chilicotal Spring Complex

Chilicotal Spring Complex (Figure 16 above) is a rheocrene spring (a spring that emerges into one or more stream channels) located inside a drainage in the desert shrublands northeast of Chilicotal Mountain. The WY2022 visit occurred on 07 February 2022, and the spring was wetted (contained water) at the time of sampling. The spring emerges from the side of a steep and densely vegetated bank, forming a small stream that goes underground intermittently inside a gravelly channel.

Site Condition

In WY2022, Chilicotal Spring Complex was highly disturbed by recent flooding (rated undisturbed in the past). The marshy, cattail-filled pool that characterized this spring complex since 2018 has been heavily scoured, removing all emergent vegetation; large debris and gravel deposits have now filled the area that previously was a pool. The primary orifice now feeds into the main wash in a narrow, slow-flowing stream (Figure 17). The spring was slightly disturbed by wildlife use (javelina, bear, and other tracks throughout the spring-affected area; rated undisturbed to slightly disturbed in the past). No other natural or human-caused disturbances were observed at Chilicotal Spring Complex in WY2022.

We did not observe invasive aquatic animals (e.g., crayfish or American bullfrogs [Lithobates catesbeianus]), but did observe three invasive plants in the vicinity of the spring: bermudagrass (Cynodon dactylon) in scattered patches, 1–5 Lehmann lovegrass (Eragrostis lehmanniana) plants, and 1–5 tamarisk (Tamarix sp.) plants. Overall, invasive plant density was similar to prior visits. Numerous obligate/facultative wetland plants were observed at Chilicotal Spring Complex, including cattails (Typhaceae), flatsedge (Cyperus sp.), mule-fat (Baccharis salicifolia), rushes (Juncaceae), spikerush (Eleocharis sp.), tamarisk (Tamarix sp.), and willow (Salix sp.).

A person pointing to a small stream flowing in a scoured drainage lined by desert shrubs.
Figure 17. The scoured wash and narrow, trickling stream where a large cattail pool held water until a recent flood event. This is part of the Chilicotal Spring Complex at Big Bend National Park.

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Water Quantity

The temperature sensor, deployed in WY2021 for monitoring water persistence, could not be found (it was likely washed away or buried under sediment from the flood event). Therefore, temperature data that are used to estimate water persistence from February 2021 to February 2022 were lost. A new sensor was deployed at the orifice in February 2022. In prior water years, the spring was wetted (contained water) 51.4–99.4% of the days measured (Figure 18).

Bar graph of water persistence showing the spring is generally wetted October to April with periods of drying in summer with large sections of missing data in water years 2018 and 2021, and all of 2017 and 2022.
Figure 18. Water persistence in Chilicotal Spring Complex, Big Bend National Park.

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Discharge was estimated at 25.9 ± 1.3 L/min (6.8 ± 0.3 gal/min) in WY2022. Due to the flood event, we utilized a new sampling location for discharge in WY2022 and previous measurements are unavailable for comparison (Table 5).

Wetted extent was measured over the first 100 m using a method for flowing water. Total brook length was estimated at > 500 m (> 1,640 ft). Width and depth averaged 102.1 cm (40.2 in) and 2.0 cm (0.8 in), respectively (Table 6). Compared to prior years, the measured springbrook was narrower and shallower in WY2022. The longer brook length in WY2022 reflects the accessibility of a longer reach of the channel and does not reflect an actual increase in springbrook length.

Water Quality

Core water quality data (Table 7) were collected at the primary sampling location near the orifice. Specific conductivity, total dissolved solids, and pH were within the range of values previously observed at the spring. Dissolved oxygen was higher, and temperature was lower than prior measurements. Core water chemistry data (Table 8) were also collected at the primary sampling location. Alkalinity, chloride, and potassium were within range of prior measurements. Calcium and sulphate values were higher, while magnesium was slightly lower. The results are presented in the following tables along with ranges of prior values (2018–2021).

Chilicotal Spring Complex Data Tables

Person crouching on a drainage bank pointing at stagnant water that is barely discernable beneath thick brush.
Figure 19. De La Ho Spring at Big Bend National Park, March 2022.

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WY2022 Findings at De La Ho Spring

De La Ho Spring (Figure 19 above) is a helocrene spring (a spring that emerges into marshy, wet meadow settings—low-gradient wetlands) located about 3 km southeast of Cerro Castolon. The WY2022 visit occurred on 04 March 2022, and the spring was wetted (contained water) at the time of sampling. De La Ho Spring is a shallow pool guarded by a dense thicket on the edge of a wash and confined by a rock wall on one edge of the pool.

Site Condition

In WY2022, De La Ho Spring was slightly disturbed by livestock (mule tracks and scat around the spring; rated undisturbed in the past), slightly disturbed by flow modification (a rock embankment near the primary orifice; rated undisturbed to highly disturbed in the past), slightly disturbed by drying (a decrease in the pool size compared to prior years; rated undisturbed to slightly disturbed in the past), and slightly disturbed by wildlife use (tracks and scat; rated slightly disturbed in the past). No other natural or human-caused disturbances were observed at De La Ho Spring in WY2022.

Several native anurans were observed in the pool, but we did not find any invasive aquatic animals (e.g., crayfish or American bullfrogs [Lithobates catesbeianus]). One invasive plant, tree tobacco (Nicotiana glauca), was present in scattered patches that were similar in density to prior visits. We observed the following obligate/facultative wetland plants: mule-fat (Baccharis salicifolia), willow (Salix sp.), and rushes (Juncaceae).

Water Quantity

The temperature sensor indicated that De La Ho Spring was wetted for 155 of 155 days measured (100% of days) up to the WY2022 visit (Figure 20). In prior water years, the spring was wetted 100% of the days measured.

An area chart showing that the spring has been consistently wet from February 2018 through February 2022. There are missing data from water year 2017 through the middle of water year 2018.
Figure 20. Water persistence in De La Ho Spring, Big Bend National Park.

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As in past years, there was no measurable discharge in WY2022. Wetted extent was measured using a method for standing water. Pool width averaged 3.32 m (10.89 ft), length averaged 5.34 m (17.52 ft), and depth averaged 2.0 cm (0.8 in). Compared to prior years (2018–2021), the pool was smaller and shallower in WY2022 (Table 9).

Water Quality

Core water quality data (Table 10) were collected at the edge of the pool near a rock wall. Dissolved oxygen, temperature, and pH were within the range of prior observations (2018–2021). Specific conductivity and total dissolved solids were higher than the range of prior measurements. Core water chemistry data (Table 11) were collected at the same sampling location. The values for alkalinity, chloride, potassium, magnesium, and sulphate were within range of prior observations, while calcium was higher. The results are presented in the following tables along with ranges of prior values (2018–2021).

De La Ho Spring Data Tables

A 7 meter by 5 meter pool of water surrounded by dried grasses and leafless trees.
Figure 21. Government Spring at Big Bend National Park, February 2022.

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WY2022 Findings at Government Spring

Government Spring (Figure 21 above) is a limnocrene spring (a spring emerging as a pool) located near an established campsite and the intersection of Grapevine Hills Road and the main park road. The WY2022 visit occurred on 17 February 2022, and the spring was wetted (contained water) at the time of sampling. The spring is diverted into a locked springbox. The spring also forms a pool located 15–20 m downslope of the springbox, with no surface channel connecting the two. Water in the springbox and pool is cool and clear with significant leaf litter from surrounding trees.

Site Condition

In WY2022, Government Spring was slightly disturbed by roads/OHV trails (a road < 50 m away from the spring; rated undisturbed in the past), slightly disturbed by drying (a decrease in the pool size compared to 2019–2021 visits; rated undisturbed to slightly disturbed in the past), and slightly disturbed by wildlife use (deer and javelina tracks around the pool; rated slightly to moderately disturbed in the past). The spring was also moderately disturbed by hiking trails (social trails from a nearby campsite; rated moderately to highly disturbed in the past), moderately disturbed by contemporary human use (boot prints and trash in the area surrounding the spring; rated moderately to highly disturbed in the past), moderately disturbed by exotic plant removal (presence of tree stumps across more than half of the spring-affected area; rated undisturbed to moderately disturbed in the past), and highly disturbed by flow modification (confinement of the spring to a springbox; rated highly disturbed in the past). No other natural or human-caused disturbances were observed at Government Spring in WY2022.

We did not observe invasive aquatic animals (e.g., crayfish or American bullfrogs [Lithobates catesbeianus]), but did observe invasive plants in scattered patches: Lehmann lovegrass (Eragrostis lehmanniana) and horehound (Marrubium vulgare). We found the following obligate/facultative wetland plants: common buttonbush (Cephalanthus occidentalis), cottonwood (Populus sp.), and mule-fat (Baccharis salicifolia).

Water Quantity

The temperature sensor inside the springbox indicated that Government Spring was wetted for 99 of 140 days measured (70.7% of days) up to the WY2022 visit (Figure 22). In prior water years, the springbox contained water 59.2–84.9% of the days measured.

Area chart showing the spring mostly wet with intermittent dry periods from April 2019 to April 2020. After that, the spring was predominantly wet in fall/winter and dry in summer/spring with intermittent wet periods.
Figure 22. Water persistence in Government Spring, Big Bend National Park.

NPS

As in past years, there was no measurable discharge in WY2022. Wetted extent of the pool was measured using the method for standing water. Pool width averaged 2.42 m (7.94 ft), length averaged 3.64 m (11.94 ft), and depth averaged 10.0 cm (3.9 in). Compared to prior years (2019–2021), the wetted area was smaller in WY2022 (Table 12).

Water Quality

Core water quality data (Table 13) were collected inside the springbox at Government Spring. Dissolved oxygen was higher than prior years, while specific conductivity, temperature, total dissolved solids, and pH were slightly lower than prior years. Core water chemistry data were also collected inside the springbox (Table 14). Alkalinity, calcium, and chloride were slightly higher than prior years, while magnesium, potassium, and sulphate were within range of past values. The results are presented in the following tables along with ranges of prior of values (2019–2021).

Government Spring Data Tables

A blue-green pool of water surrounded and somewhat obscured by overhanging dry vegetation on the banks and bright green plants growing in and next to the water channel flowing from the pool.
Figure 23. Grapevine Spring at Big Bend National Park, February 2022.

NPS

WY2022 Findings at Grapevine Spring

Grapevine Spring (Figure 23 above) is a rheocrene spring (a spring that emerges into one or more stream channels) located northeast of the Grapevine Hills. The WY2022 visit occurred on 09 February 2022, and the spring was wetted (contained water) at the time of sampling. The spring emerges from an undercut bank inside a wash, forming a narrow channel with slow flow, and a series of small, shallow pools. Aquatic plants and animals are abundant at the spring.

Site Condition

In WY2022, Grapevine Spring was slightly disturbed by recent flooding (significant erosion surrounds the pool at the primary orifice, stripping away some of the surrounding vegetation; rated undisturbed to slightly disturbed in the past), slightly disturbed by drying (a decrease in channel length compared to the 2018–2021 visits; rated undisturbed to slightly disturbed in the past), and moderately disturbed by wildlife (tracks, scat, and a deer carcass at the spring; rated slightly disturbed in the past). No other natural or human-caused disturbances were observed at Grapevine Spring in WY2022.

We observed several native anurans at the spring, but no invasive aquatic animals (e.g., crayfish or American bullfrogs [Lithobates catesbeianus]) and no invasive plants. We observed the following obligate/facultative wetland plants: bluestem (Andropogon sp.), maidenhair fern (Adiantum sp.), mule-fat (Baccharis salicifolia), spikerush (Eleocharis sp.), and willow (Salix sp.), all of which had been observed in the past.

Water Quantity

The temperature sensor indicated that Grapevine Spring was wetted for 120 of 132 days measured (90.9% of days) up to the WY2022 visit (Figure 24). In prior water years, the spring was wetted 72.6–100% of the days measured.

Area chart showing that the spring has been wet since February 2018 with a dry period between June and October of 2021, and no data prior to February 2018.
Figure 24. Water persistence in Grapevine Spring, Big Bend National Park.

NPS

Spring discharge was estimated at 3.9 ± 0.0 L/min (1.0 ± 0.0 gal/min) in WY2022. We utilized a new sampling location for discharge in WY2022 and previous measurements are unavailable for comparison (Table 15).

Wetted extent was evaluated using the method for flowing water. The total brook length was 15.1 m (49.5 ft), and width and depth averaged 67.0 cm (26.4 in) and 20.3 cm (8.0 in), respectively (Table 16). Compared to prior years (2018–2021), the springbrook was shorter in WY2022.

Water Quality

Core water quality data (Table 17) were collected at the primary sampling location, 2–3 m away from the actual orifice, where the pool becomes safely accessible. Dissolved oxygen was higher than prior years (2018–2021), while specific conductivity, total dissolved solids, and water temperature were lower. The pH value was within range of prior values. Core water chemistry data (Table 18) were taken at the same sampling location. The values for alkalinity, chloride, magnesium, potassium, and sulphate were within range of prior values, while calcium was slightly higher. The results are presented in the following tables along with ranges of prior values (2018–2021).

Grapevine Spring Data Tables

Bright green plants and ferns hanging on a cliff wall that trickles water under the ferns down into a pool of water surrounded by large boulders and gravel deposits.
Figure 25. Lorn Spring at Big Bend National Park, February 2022.

NPS

WY2022 Findings at Lorn Spring

Lorn Spring (Figure 25 above) is a hanging garden spring (complex, multi-habitat spring that emerges along geologic contacts and seeps onto underlying walls) located inside a wash northwest of the Grapevine Hills. The WY2022 visit occurred on 09 February 2022, and the spring was wetted (contained water) at the time of sampling. Lorn Spring slowly drips from a rock face covered in maidenhair fern (Adiantum sp.) at the base of a north-facing pouroff. Water from the hanging garden collects into small pools of cool, clear water at the base of the cliff.

Site Condition

In WY2022, Lorn Spring was slightly disturbed by recent flooding (presence of flood debris and impacts to vegetation; rated slightly to highly disturbed in the past), and slightly disturbed by wildlife (javelina and deer tracks in the spring-affected area; rated undisturbed to moderately disturbed in the past). No other natural or human-caused disturbances were observed at Lorn Spring in WY2022.

We did not observe invasive aquatic animals (e.g., crayfish or American bullfrogs [Lithobates catesbeianus]). We found one invasive plant in scattered patches, Lehmann lovegrass (Eragrostis lehmanniana). We found the following obligate/facultative wetland plants: common buttonbush (Cephalanthus occidentalis), maidenhair fern (Adiantum sp.), and mule-fat (Baccharis salicifolia).

Water Quantity

The temperature sensor indicated that Lorn Spring was wetted for 126 of 132 days measured (95.5% of days) up to the WY2022 visit (Figure 26). In prior water years, the spring was wetted 42.1–83.8% of the days measured.

Area chart showing the spring is wet in fall and winter months and regular periods of dryness that vary in length during summer. Water year 2020 was mostly dry while summer of 2021 had intermittent dry periods. There are no data prior to February 2020.
Figure 26. Water persistence in Lorn Spring, Big Bend National Park.

NPS

Discharge was estimated at 0.6 ± 0.1 L/min (0.16 ± 0.03 gal/min) in WY2022. Compared to previous measurements, discharge was near the upper end of the range of historical values (Table 19).

Wetted extent was evaluated using a method for standing water. Width averaged 119.2 cm (46.9 in), length averaged 1.51 m (4.95 ft), and depth averaged 6.3 cm (2.5 in). These measurements were within the range of previous values (Table 20).

Water Quality

Core water quality data (Table 21) were collected at the primary sampling location in the deepest part of the largest pool at the base of the hanging garden. The values for pH and dissolved oxygen were within the range of prior observations, while specific conductivity, water temperature, and total dissolved solids were slightly lower. Core water chemistry data (Table 22) were collected at the same sampling location. Potassium and sulphate were within the range of prior values. Calcium was higher, while magnesium, alkalinity, and chloride were lower. The results are presented in the following tables along with ranges of prior values (2019–2021).

Lorn Spring Data Tables

A large pond that is so dense with dried cattails that the water is obscured. Mineral deposits line the banks due to evaporative drying.
Figure 27. Lower Croton Spring at Big Bend National Park, February 2022.

NPS

WY2022 Findings at Lower Croton Spring

Lower Croton Spring (Figure 27 above) is a helocrene spring (a spring that emerges into marshy, wet meadow settings—low-gradient wetlands) located north of the Chisos Mountains and south of Croton Peak. The WY2022 visit occurred on 08 February 2022, and the spring was wetted (contained water) at the time of sampling. The spring forms a pool about 20 m wide and 20 m long that is populated by a dense stand of cattails (Typhaceae).

Site Condition

In WY2022, Lower Croton Spring was slightly disturbed by hiking trails (a trail that leads to the spring from a nearby campsite; rated slightly to moderately disturbed in the past), slightly disturbed by contemporary human use (recent tracks on the trail to the spring; rated slightly to moderately disturbed in the past), slightly disturbed by wildlife use (tracks in the mud surrounding the spring; rated slightly to moderately disturbed in the past), and moderately disturbed by drying (withering of cattails at the site and mineral deposits on the banks resulting from evaporation; rated undisturbed to highly disturbed in the past). No other natural or human-caused disturbances were observed at Lower Croton Spring in WY2022.

We did not observe invasive aquatic animals (e.g., crayfish or American bullfrogs [Lithobates catesbeianus]), but did observe two invasive plants: bermudagrass (Cynodon dactylon) in a matrix and Russian thistle (Salsola sp.) in scattered patches. We also observed the following obligate/facultative wetland plants: cattail, mule-fat (Baccharis salicifolia), and rushes (Juncaceae).

Water Quantity

The temperature sensor indicated that Lower Croton Spring was wetted for 131 of 131 days measured (100% of days) up to the WY2022 visit (Figure 28). In prior water years, the spring was wetted 29.1–100% of the days measured.

Area chart of water persistence showing the spring has been consistently wet since March of 2019 and previous to that, there were long periods of intermittent wet and dry periods.
Figure 28. Water persistence in Lower Croton Spring, Big Bend National Park.

NPS

As in past years, there was no measurable discharge. Wetted extent was evaluated using a method for standing water. Width averaged 15.48 m (50.79 ft), length averaged 16.92 m (55.51 ft), and depth averaged 7.3 cm (2.9 in). Compared to prior years, the pool was slightly shorter in length (Table 23) but comparable in width and depth in WY2022.

Water Quality

Core water quality data (Table 24) were collected at the primary sampling location near the edge of the pool. The value for total dissolved solids was within range of prior values, while dissolved oxygen was slightly higher. Specific conductivity, temperature, and pH were lower than prior values. Water chemistry data (Table 25) were collected at the same sampling location. Alkalinity, calcium, chloride, potassium, and sulphate were within range of prior values, while magnesium was slightly lower. The results are presented in the following tables along with ranges of prior values (2018–2021).

Lower Croton Spring Data Tables

A trickle of water flowing through ferns growing off the adjacent boulders in a drainage filled with large boulders.
Figure 29. Mule Ears Spring at Big Bend National Park, March 2022.

NPS

WY2022 Findings at Mule Ears Spring

Mule Ears Spring (Figure 29 above) is a hanging garden spring (a complex, multi-habitat spring that emerges along geologic contacts and seeps onto underlying walls) located north of the Mule Ears Peaks. The WY2022 visit occurred on 03 March 2022, and the spring was wetted (contained water) at the time of sampling. The primary orifice seeps from a rock face and creates a small pool bounded by boulders. Spring flow continues out of the pool and into a narrow channel, collecting input from more seeps along the adjacent wall as it flows through dense vegetation.

Site Condition

In WY2022, Mule Ears Spring was slightly disturbed by contemporary human use (hiking trail leading to the spring; rated undisturbed to moderately disturbed in the past) and moderately disturbed by hiking trails (heavy use of the trail; rated moderately to highly disturbed in the past). No other natural or human-caused disturbances were observed at Mule Ears Spring in WY2022.

We observed Rio Grande leopard frogs at the spring, but no invasive aquatic animals (e.g., crayfish or American bullfrogs [Lithobates catesbeianus]). We did observe the following invasive plants: bermudagrass (Cynodon dactylon) in evenly distributed patches, 1–5 tree tobacco (Nicotiana glauca) plants, and 1–5 sowthistle (Sonchus sp.) plants. We also observed the following obligate/facultative wetland plants: bluestem (Andropogon sp.), cattail (Typhaceae), lobelia (Lobelia sp.), maidenhair fern (Adiantum sp.), mule-fat (Baccharis salicifolia), and willow (Salix sp.), all of which had been observed at Mule Ears Spring during previous visits.

Water Quantity

The temperature sensor indicated that Mule Ears Spring was wetted for 154 of 154 days measured (100% of days) up to the WY2022 visit (Figure 30). In prior water years, the spring was wetted 100% of the days measured.

Area chart of water persistence showing that the spring has been consistently wet since March of 2019 when monitoring began.
Figure 30. Water persistence in Mule Ears Spring, Big Bend National Park.

NPS

Discharge was estimated at 1.6 ± 0.1 L/min (0.42 ± 0.03 gal/min) in WY2022. This measurement was taken at a new sampling location directly at the primary orifice. Prior discharge data from WY2018–2021 ranged from 3.2–13.7 L/min, but discharge was sampled further downstream, likely capturing water from multiple orifices (Table 26).

Wetted extent was evaluated using a method for flowing water. The total brook length was 23.7 m (77.8 ft). Width and depth averaged 52.9 cm (20.8 in) and 8.5 cm (3.3 in), respectively (Table 27). The pool was somewhat narrower than in prior years (2018–2021), but comparable in length and depth.

Water Quality

Core water quality data (Table 28) were collected at the primary sampling location in a small pool fed by the primary orifice. Dissolved oxygen and pH were within the range of prior values, while specific conductivity, temperature, and total dissolved solids were lower. Core water chemistry data (Table 29) were collected at the same sampling location. Alkalinity and sulphate were within the range of prior values, while magnesium was five times higher than the previous highest observation. Continued annual monitoring at this location will clarify if the unusually high value was due to a sample processing error, transient spike, or lasting shift. The value for chloride was excluded for not meeting the Chihuahuan Desert Network’s data quality standards as outlined in the protocol. Calcium and potassium were slightly lower than prior years. Results are presented in the following tables along with ranges of prior values (2018–2021).

Mule Ears Spring Data Tables

Very small pools and wet sandy areas on the side of a larger drainage in a desert shrubland.
Figure 31. Painted Hills Spring at Big Bend National Park, February 2022.

NPS

WY2022 Findings at Painted Hills Spring

Painted Hills Spring (Figure 31 above) is a rheocrene spring (a spring that emerges into one or more stream channels) located in a small wash on the northern edge of the Painted Hills. The WY2022 visit occurred on 18 February 2022, and the spring was wetted (contained water) at the time of sampling. Painted Hills Spring is a small seep emerging from two distinct bedrock seams inside a wash, creating a short (4 m long), brook consisting of isolated pools/puddles with no visible nexus between pools and no discernable flow.

Site Condition

In WY2022, Painted Hills Spring was slightly disturbed by drying. The primary orifice and sampling location had completely dried out, and the secondary orifice was damp but not flowing (rated slightly to moderately disturbed in the past). The spring was slightly disturbed by wildlife use (tracks and scat; rated undisturbed to slightly disturbed in the past), and highly disturbed by livestock use (mule droppings and tracks; rated undisturbed to slightly disturbed in the past). No other natural or human-caused disturbances were observed at Painted Hills Spring in WY2022.

We did not observe invasive aquatic animals (e.g., crayfish or American bullfrogs [Lithobates catesbeianus]), but observed the following invasive plants: bermudagrass (Cynodon dactylon) in evenly distributed patches and Lehmann lovegrass (Eragrostis lehmanniana) in scattered patches. We also observed the following obligate/facultative wetland plants: cottonwood (Populus sp.), mule-fat (Baccharis salicifolia), and willow (Salix sp.).

Water Quantity

The temperature sensor indicated that Painted Hills Spring was wetted for 1 of 131 days measured (0.8% of days) up to the WY2022 visit (Figure 32). In prior water years, the spring was wetted 3.6–94.1% of the days measured.

Area chart of water persistence showing the spring mostly wetted between February 2018 and June 2019, but since then, it has been mostly dry with periods of spring flow mostly in the winter and spring and missing data in WY2017 and half of WY2018.
Figure 32. Water persistence in Painted Hills Spring, Big Bend National Park.

NPS

As in past site visits, there was no measurable discharge. Wetted extent was evaluated using a method for flowing water. The wetted extent was comparable in length and width to prior years, and slightly deeper. The total brook length was 5.0 m (16.4 ft). Width and depth averaged 70.8 cm (27.9 in) and 1.1 cm (0.4 in), respectively (Table 30).

Water Quality

Core water quality (Table 31) and water chemistry (Table 32) data could not be collected at the primary sampling location (001) because it was dry. Instead, water quality measurements were taken < 2 m away at sampling location 003. Our results may be influenced by this shift in location. The values for dissolved oxygen and pH were higher than prior observations, while specific conductivity, water temperature, and total dissolved solids were lower. Calcium, chloride, magnesium, potassium, and sulphate were within range of prior values, while alkalinity was lower. Results are presented in the following tables along with ranges of prior values (2017–2021).

Painted Hills Spring Data Tables

A person crouched down holding a water bottle sample by a shallow water channel in a vegetation filled depression.
Figure 33. Peña Spring 1 at Big Bend National Park, March 2022.

NPS

WY2022 Findings at Peña Spring 1

Peña Spring 1 (Figure 33 above) is a rheocrene spring (a spring that emerges into one or more stream channels) that emerges inside a drainage near the Chimneys Trail, east of Old Maverick Road. The WY2022 visit occurred on 03 March 2022, and the spring was wetted (contained water) at the time of sampling. Multiple orifices and a hanging garden inside the wash contribute to a springbrook that flows for more than 100 m. Steep banks and trees overhang the channel. Aquatic life is abundant, including anurans, macroinvertebrates, and a host of wetland plants.

Site Condition

In WY2022, Peña Spring 1 was slightly disturbed by wildlife use (various tracks and a javelina sighting near the site; rated slightly to highly disturbed in the past). No other natural or human-caused disturbances were observed at Peña Spring 1 in WY2022.

We did not observe invasive aquatic animals (e.g., crayfish or American bullfrogs [Lithobates catesbeianus]) and did not find any invasive plants. We found the following obligate/facultative wetland plants: bluestem (Andropogon sp.), flatsedge (Cyperus sp.), maidenhair fern (Adiantum sp.), mule-fat (Baccharis salicifolia), spikerush (Eleocharis sp.), and willow (Salix sp.).

Water Quantity

The temperature sensor failed shortly after deployment in WY2021; therefore, no persistence data are available for WY2022. In prior water years, the spring was wetted 100% of the days measured (Figure 34).

Area chart of water persistence showing the spring has been wet since March 2018 but with missing data from April 2021 through the water year 2022 visit.
Figure 34. Water persistence in Peña Spring 1, Big Bend National Park.

NPS

Discharge was not measurable in WY2022 because of the braided and low-gradient nature of the channel. Discharge data for WY2021 are in Table 33.

Wetted extent was evaluated using a method for flowing water. The total brook length was estimated at 100–200 m (328–656 ft). Width and depth averaged 177.2 cm (69.8 in) and 9.7 cm (3.8 in), respectively, within the first 100 m (Table 34). In prior years, measurements ended when the channel became unsafe to measure at approximately 50 m, but in WY2022 the channel was measurable up to 100 m. Therefore, the increase in brook length does not necessarily reflect an increase in actual length.

Water Quality

Core water quality (Table 35) and water chemistry (Table 36) data were collected at the primary sampling location in a small pool near the primary orifice. Values for dissolved oxygen, temperature, and pH were within the range of prior values, while specific conductivity and total dissolved solids were lower. Alkalinity, chloride, potassium, and sulphate were within the range of prior values, while calcium was slightly lower. The value for magnesium was excluded because it did not meet the Chihuahuan Desert Network’s data quality standards as outlined in the protocol. The results are presented in the tables below along with a range of prior values (2018–2021).

Peña Spring 1 Data Tables

A sparse desert landscape with reddish soil, dried grasses, and mineral deposits alongside a drainage that contains the springbrook.
Figure 35. Red Ass Spring at Big Bend National Park, February 2022.

NPS

WY2022 Findings at Red Ass Spring

Red Ass Spring (Figure 35 above) is a rheocrene spring (a spring that emerges into one or more stream channels) located in a drainage near the Chimneys formation. Several distinct orifices emerge within a 200 m radius, creating a complex of springs and channels in the vicinity, including multiple hanging gardens and a pouroff. We monitor one orifice and channel within the complex. The WY2022 visit occurred on 19 February 2022, and the spring was wetted (contained water) at the time of sampling. The primary orifice emerges inside a drainage and forms a shallow, silty-bottomed channel that has ranged from 7.5–12.8 m long at annual visits.

Site Condition

In WY2022, Red Ass Spring was slightly disturbed by drying (shorter brook length than previous years; rated undisturbed to moderately disturbed in the past), and moderately disturbed by wildlife use (tracks and trampling in the brook and on the banks; rated undisturbed to slightly disturbed in the past). No other natural or human-caused disturbances were observed at Red Ass Spring in WY2022.

We did not observe invasive aquatic animals (e.g., crayfish or American bullfrogs [Lithobates catesbeianus]) or invasive plants. We found the following obligate/facultative wetland plants: centaury (Centaurium sp.), cottonwood (Populus sp.), and rushes (Juncaceae).

Water Quantity

The temperature sensor indicated that Red Ass Spring was wetted for 142 of 142 days measured (100% of days) up to the WY2022 visit (Figure 36). In prior water years, the spring was wetted 28.7–66.3% of the days measured.

Area chart of water persistence showing the spring was wetted during the winter of 2019, 2021, and 2022 and prolonged dry periods in spring and summer 2018 to 2021 and winter 2019 to 2020.
Figure 36. Water persistence in Red Ass Spring, Big Bend National Park.

NPS

Discharge was estimated at 0.9 ± 0.1 L/min (0.24 ± 0.03 gal/min) in WY2022, which was within the range of prior measurements (Table 37).

Wetted extent was evaluated using a method for flowing water. The total brook length was 7.5 m (24.6 ft). Width and depth averaged 54.1 cm (21.3 in) and 1.5 cm (0.6 in), respectively (Table 38). Compared to prior years (2018–2021), brook length was somewhat shorter in WY2022, while width and depth were within the range of past measurements.

Water Quality

Core water quality (Table 39) data were collected at the primary sampling location in a small pool at the orifice. The values for specific conductivity, temperature, and total dissolved solids were within range of prior values. The value for pH was lower, while dissolved oxygen was higher than prior years. Core water chemistry (Table 40) data were collected at the same sampling location. Alkalinity, calcium, chloride, magnesium, and potassium were within range of prior values, while sulphate was slightly higher. The results are presented in the tables below along with ranges of prior values (2018–2021).

Red Ass Spring Data Tables

A desert area with exposed bedrock and shrubs and cactus. The drainage is full of shrubs covering the water from the spring.
Figure 37. Rough Spring B at Big Bend National Park, March 2022.

NPS

WY2022 Findings at Rough Spring B

Rough Spring B (Figure 37 above) is a rheocrene spring (a spring that emerges into one or more stream channels) located inside a drainage on the north slopes of the Chisos Mountains. The WY2022 visit occurred on 04 March 2022, and the spring was wetted (contained water). Rough Spring B emerges from under thick shrubs inside a bedrock-lined drainage. The spring forms a narrow, intermittent channel about 12 m long with minimal surface flow.

Site Condition

In WY2022, Rough Spring B was slightly disturbed by wildlife use (bear and other wildlife tracks and scat; rated undisturbed to slightly disturbed in the past), and moderately disturbed by drying (shorter and shallower springbrook when compared with previous years; rated undisturbed to moderately disturbed in the past). No other natural or human-caused disturbances were observed at Rough Spring B in WY2022.

We did not observe invasive aquatic animals (e.g., crayfish or American bullfrogs [Lithobates catesbeianus]). One invasive plant, Lehmann lovegrass (Eragrostis lehmanniana), was observed in scattered patches. Poison oak (Toxicodendron sp.) continues to line the banks around the primary orifice. We observed the following obligate/facultative wetland plants: centaury (Centaurium sp.), cottonwood (Populus sp.), mule-fat (Baccharis salicifolia), rushes (Juncaceae), and sedges (Cyperaceae).

Water Quantity

The temperature sensor indicated that Rough Spring B was wetted for 155 of 155 days measured (100% of days) up to the WY2022 visit (Figure 38). In prior water years, the spring was wetted 99.5–100% of the days measured.

Area chart of water persistence showing the spring consistently wet year round since February 2018, but with missing data from February 2020 to March 2021.
Figure 38. Water persistence in Rough Spring B, Big Bend National Park.

NPS

Discharge was not measurable in WY2022. Discharge values are only available for one recent year, WY2019 (Table 41).

Wetted extent was evaluated using a method for flowing water. The total brook length was 12.1 m (39.7 ft). Width and depth averaged 67.6 cm (26.6 in) and 3.4 cm (1.3 in), respectively. Compared to prior years (2018–2021), brook length was shorter in WY2022, while width and depth were within the range of past measurements (Table 42).

Water Quality

Core water quality (Table 43) data were collected at the primary sampling location, near the orifice. Specific conductivity, temperature, and total dissolved solids were within the range of prior values, while pH was lower and dissolved oxygen was higher. Core water chemistry (Table 44) data were collected at the same sampling location. Alkalinity, calcium, chloride, potassium, and sulphate were within the range of prior values, while magnesium was lower. The results are presented in the tables below along with ranges of prior values (2018–2021).

Rough Spring B Data Tables

Leafless mesquite trees behind shallow channels winding through dried grasses leading to wet, muddy depressions.
Figure 39. Screwbean Spring at Big Bend National Park, February 2022.

NPS

WY2022 Findings at Screwbean Spring

Screwbean Spring (Figure 39 above) is a rheocrene spring (a spring that emerges into one or more stream channels) located on a floodplain near an active, channelized wash along Black Gap Road. The WY2022 visit occurred on 06 February 2022, and the spring was wetted (contained water) at time of sampling. The spring flows from several orifices and forms small, braided channels that meander into a wetland with dense grasses and screwbean mesquite trees (Prosopis pubescens). Multiple intermittently wetted seeps are present in the surrounding area.

Site Condition

In WY2022, Screwbean Spring was slightly disturbed by drying (drying of one of the previously flowing orifices and water-stressed vegetation surrounding the spring; rated slightly to moderately disturbed in the past). The spring was also slightly disturbed by wildlife (tracks in the spring-affected area; rated undisturbed to moderately disturbed in the past). No other natural or human-caused disturbances were observed at Screwbean Spring in WY2022.

We did not observe invasive aquatic animals (e.g., crayfish or American bullfrogs [Lithobates catesbeianus]). One invasive plant, tamarisk (Tamarix sp.), was present (1–5 individual plants). We found the following obligate/facultative wetland plants: bluestem (Andropogon sp.), spikerush (Eleocharis sp.), and tamarisk (Tamarix sp.).

Water Quantity

The temperature sensor indicated that Screwbean Spring was wetted for 129 of 129 days measured (100% of days) up to the WY2022 visit (Figure 40). In prior water years, the spring was wetted 89.2–100% of the days measured.

Area chart of water persistence showing the spring has been wet all year round since monitoring began in 2018 except for dry period summer 2018.
Figure 40. Water persistence in Screwbean Spring, Big Bend National Park.

NPS

Discharge was not measureable in WY2022 because of a lack of surface flow. Discharge values for 2018–2021 can be found in Table 45.

We have switched from a standing water method for wetted extent at Screwbean Spring to a flowing water method. Standing water wetted extent measurements for WY2018–WY2019 can be found in Table 46, and flowing water wetted extent values for WY2020 onward can be found in Table 47. The total brook length in WY2022 was 20.3 m (66.6 ft). Width and depth averaged 62.5 cm (24.6 in) and 2.8 cm (1.1 in), respectively.

Water Quality

Core water quality (Table 48) data were collected at the primary sampling location near the orifice. Dissolved oxygen, specific conductivity, temperature, total dissolved solids, and pH were all within the range of prior values. Core water chemistry (Table 49) data were collected at the same sampling location. The values for alkalinity, calcium, magnesium, and sulphate were within range of prior values. Chloride was lower than prior observations, and potassium was higher. The results are presented in the tables below along with ranges of prior values (2018–2021).

Screwbean Spring Data Tables

A rock face covered in green plants (a hanging garden) where water trickles out and down towards green shrubs and trees.
Figure 41. Shelf Spring at Big Bend National Park, February 2022.

NPS

WY2022 Findings at Shelf Spring

Shelf Spring (Figure 41 above) is a hanging garden spring (complex, multi-habitat spring that emerges along geologic contacts and seeps onto underlying walls) that forms a channel in a drainage north of Black Gap Road. The WY2022 visit occurred on 06 February 2022, and the spring was wetted (contained water) at the time of sampling. The hanging garden produces very little flow (Figure 42), and that flow goes subsurface at the base of the rock face. The spring re-emerges about 5 m away to form a narrow stream that flows intermittently for approximately 30 m.

A person pointing at the wet area of a hanging garden (green vegetation on the cliff face).
Figure 42. Closeup view of the hanging garden at Shelf Spring.

NPS

Site Condition

In WY2022, Shelf Spring was slightly disturbed by wildlife use (tracks and game trails in the spring-affected area; rated slightly disturbed in the past). No other natural or human-caused disturbances were observed at Shelf Spring in WY2022.

We did not observe invasive aquatic animals (e.g., crayfish or American bullfrogs [Lithobates catesbeianus]) or invasive plants. We found the following obligate/facultative wetland plants: bluestem (Andropogon sp.), maidenhair fern (Adiantum sp.), and mule-fat (Baccharis salicifolia).

Water Quantity

The temperature sensor indicated that Shelf Spring was wetted for 129 of 129 days measured (100% of days) up to the WY2022 visit (Figure 43). In prior water years, the spring was wetted 100% of the days measured.

Area chart of water persistence showing the spring was continuously wet since February 2019 but with missing data before February 2019 and from February 2020 to February 2021.
Figure 43. Water persistence in Shelf Spring, Big Bend National Park.

NPS

Discharge was not measured in WY2022 due to lack of flow at the primary sampling location. Wetted extent was evaluated using a method for flowing water. The total brook length was 29.8 m (97.8 ft). Width and depth averaged 17.2 cm (6.8 in) and 0.5 cm (0.2 in), respectively (Table 50). Overall, wetted extent at Shelf Spring in WY2022 was comparable to prior years (2018–2021).

Water Quality

Core water quality (Table 51) data were collected at the primary sampling location, which is the pool closest to the hanging garden. Dissolved oxygen and pH values were within the range of prior values, while specific conductivity, temperature, and total dissolved solids were lower. Core water chemistry (Table 52) data were collected at the same sampling location. Alkalinity and magnesium were within the range of prior values, while calcium, potassium, and sulphate were higher. The value for chloride was lower than previously observed. The results are presented in the tables below along with ranges of prior values (2018–2021).

Shelf Spring Data Tables

Two people standing in an area with mineral covered soil and dried grasses and plants on a slope where the primary orifice is above a narrow, sandy drainage.
Figure 44. Solis Spring at Big Bend National Park, February 2022.

NPS

WY2022 Findings at Solis Spring

Solis Spring (Figure 44 above) is a rheocrene spring (a spring that emerges into one or more stream channels) located inside a drainage southeast of Talley Mountain. The WY2022 visit occurred on 08 February 2022, and the spring was wetted (contained water) at the time of sampling. Solis Spring is a complex of small seeps on the edge of a drainage, forming shallow, silt-bottomed pools along the bank. At higher flows, the seeps may form small channels that join and flow into the main drainage, but at lower flows, the surface water is stagnant. Thick mineral deposits line the banks surrounding Solis Spring.

Site Condition

In WY2022, Solis Spring was slightly disturbed by drying (drying out of one of the previously flowing orifices and presence of water-stressed wetland plants, including spikerush (Eleocharis sp.) and cattails (Typhaceae); rated undisturbed to moderately disturbed in the past). The spring was also slightly disturbed by wildlife use (tracks and browsing on the wetland plants; rated undisturbed to moderately disturbed in the past). No other natural or human-caused disturbances were observed at Solis Spring in WY2022.

We did not observe invasive aquatic animals (e.g., crayfish or American bullfrogs [Lithobates catesbeianus]). Two invasive plants were noted: 1–5 tree tobacco (Nicotiana glauca) plants and 1–5 tamarisk (Tamarix sp.) plants. We observed the following obligate/facultative wetland plants: cattails (Typhaceae), centaury (Centaurium sp.), rushes (Juncaceae), spikerush (Eleocharis sp.), and tamarisk (Tamarix sp.), all of which have been observed at this site in the past.

Water Quantity

The temperature sensor indicated that Solis Spring was wetted 131 of 131 days measured (100% of days) up to the WY2022 visit (Figure 45). In prior water years, the spring was wetted 83.5–100% of the days measured.

Area chart of water persistence showing the spring was wet all year round since monitoring began in 2018 except for a dry period from April to May of 2018. There are no data prior to 2018.
Figure 45. Water persistence in Solis Spring, Big Bend National Park.

NPS

Discharge was not measured in WY2022. Wetted extent was evaluated using a method for flowing water. The total brook length was 12.8 m (42.0 ft). Width and depth averaged 14.0 cm (5.5 in) and 1.5 cm (0.6 in), respectively (Table 53).

Water Quality

Core water quality (Table 54) data were collected at the primary sampling location (002) and water chemistry (Table 55) data were collected at an alternate sampling location (001). These sampling locations are within a few meters of each other on the same bank. Values for specific conductivity and total dissolved solids were much higher than prior values (nearly five times higher), while dissolved oxygen and temperature were lower. The value for pH was 9.62, higher than the range of previous measurements. Continued annual monitoring at this location will clarify if the unusually high values were due to sampling or sensor errors, transient spikes, or a lasting shift. Chloride, magnesium, and potassium were within the range of prior values, while alkalinity was lower. Calcium and sulphate were higher than prior values. The results are presented in the tables below along with ranges of prior values (2018–2021).

Solis Spring Data Tables

A person crouching by two small pools of water holding a water quality instrument in the water in a muddy drainage surrounded by dried grasses and steep slopes.
Figure 46. Tiptoe Spring at Big Bend National Park, February 2022.

NPS

WY2022 Findings at Tiptoe Spring

Tiptoe Spring (Figure 46 above) is a rheocrene spring (a spring that emerges into one or more stream channels) in a drainage on the east side of Hannold Hill. The WY2022 visit occurred on 09 February 2022, and the spring was wetted (contained water) at time of sampling. The spring emerges inside a wash lined with shrubs and boulders. Depending on flow, the spring may form a slowly flowing channel, or a series of stagnant, shallow, silty pools.

Site Condition

In WY2022, Tiptoe Spring was moderately disturbed by wildlife use (tracks and trampling throughout the spring-affected area; rated slightly to moderately disturbed in the past). No other natural or human-caused disturbances were observed at Tiptoe Spring in WY2022.

We did not observe invasive aquatic animals (e.g., crayfish or American bullfrogs [Lithobates catesbeianus]) or invasive plants. We found the following obligate/facultative plants: bluestem (Andropogon sp.), centaury (Centaurium sp.), rushes (Juncaceae), and spikerush (Eleocharis sp.).

Water Quantity

The temperature sensor indicated that Tiptoe Spring was wetted for 133 of 137 days measured (97.1% of days) up to the WY2022 visit (Figure 47). In prior water years, the spring was wetted 50–100% of the days measured.

Area chart of water persistence showing spring wet from February 2021 to February 2022, 1st half WY2019, and 2nd half WY2018. Dry periods were 1st half WY2020 and 2nd half WY2019. Data missing prior to February 2018 and April 2020 to February 2021.
Figure 47. Water persistence in Tiptoe Spring, Big Bend National Park.

NPS

Discharge was not measured in WY2022 due to a lack of flow. Data from prior years are included in Table 56. Wetted extent was evaluated using a method for flowing water. The total brook length was 58.0 m (190.3 ft). Width and depth averaged 29.5 cm (11.6 in) and 0.6 cm (0.2 in), respectively (Table 57). The wetted area was within the range of previous measurements.

Water Quality

Core water quality data were collected in the largest pool near the orifice (Table 58). Sample results from previous visits were excluded because of not meeting the Chihuahuan Desert Network’s data quality standards, as outlined in the protocol. Water chemistry data were sampled approximately 2 m downstream of the orifice (Table 59). The values for alkalinity, calcium, chloride, and potassium were within the range of prior values. Magnesium was higher than prior values, and sulphate was lower. The results are presented in the tables below along with ranges of prior values (2018–2021).

Tiptoe Spring Data Tables

Scientists near a giant pool of water in a bedrock basin in a steep, rock-lined drainage and evidence (water marks) that water flows from above into the pool and out from the pool down the drainage.
Figure 48. Water Boy Tinaja at Big Bend National Park, February 2022.

NPS

WY2022 Findings at Water Boy Tinaja

Water Boy Tinaja (Figure 48 above) is a bedrock pool in a bedrock canyon on the northeast edge of the Chisos Mountains. The WY2022 visit occurred on 17 February 2022, and the tinaja was wetted (contained water) at the time of sampling. The tinaja is about 5.5 m long by 4.5 m wide and 0.5 m deep. Water Boy Tinaja collects runoff from the surrounding canyon, and at times, a channel flows out of the pool and continues down the canyon, pooling intermittently in low-gradient areas.

Site Condition

In WY2022, Water Boy Tinaja was slightly disturbed by wildlife use (browsing of vegetation in the immediate area; rated undisturbed to slightly disturbed in the past), and moderately disturbed by drying (lower water level in the tinaja than during the previous visit and the lack of inflow or outflow; rated undisturbed in the past). No other natural or human-caused disturbances were observed at Water Boy Tinaja in WY2022.

We did not observe invasive aquatic animals (e.g., crayfish or American bullfrogs [Lithobates catesbeianus]). Lehmann lovegrass (Eragrostis lehmanniana), an invasive plant, was observed near the spring (1–5 individual plants). We observed the following obligate/facultative wetland plants: rushes (Juncaceae) and sedges (Cyperaceae).

Water Quantity

The temperature sensor indicated that Water Boy Tinaja was wetted for 140 of 140 days measured (100% of days) up to the WY2022 visit (Figure 49). In prior water years, the spring was wetted 67.9–100% of the days measured.

Area chart of water persistence showing the spring was wet all year round since early water year 2017, except for a dry period during 1st half of water year 2018 and brief dry periods during summer and fall from 2017 to 2019.
Figure 49. Water persistence in Water Boy Tinaja, Big Bend National Park.

NPS

Discharge was not measurable in WY2022. Wetted extent was evaluated using a method for standing water. Width averaged 4.6 m (15.1 ft), length averaged 5.6 m (18.4 ft), and depth averaged 48.2 cm (19.0 in; Table 60). Compared to prior years, the tinaja was smaller in WY2022.

Water Quality

Core water quality (Table 61) data were collected at the primary sampling location in the center of the tinaja. Dissolved oxygen, pH, specific conductivity, and temperature were within the range of prior values, while total dissolved solids were lower. Core water chemistry (Table 62) data were collected at the same sampling location. The values for alkalinity, calcium, potassium, and sulphate were within the range of prior values, while chloride and magnesium were lower. The results are presented in the tables below along with ranges of prior values (2017–2021).

Water Boy Tinaja Data Tables

Report Citation

Authors: Susan Singley, Kara Raymond, Andy Hubbard

Singley, S., K. Raymond, and A. Hubbard. 2024. Climate and Water Monitoring at Big Bend National Park: Water Year 2022. Chihuahuan Desert Network, National Park Service, Las Cruces, New Mexico.

Past Reports

Water Year 2019 Climate and Water Monitoring at Big Bend National Park

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Last updated: March 19, 2025