Article

Climate and Water Monitoring at Amistad National Recreation Area: Water Year 2023

Four park staff members on a boat next to the shore of a reservoir surrounded by desert hills. The boat has writing that says, "National Park Service Resource Management."
Chihuahuan Desert Network monitoring crew and park staff at Amistad National Recreation Area. Amistad Reservoir receives water from basins in the U.S. and Mexico, including the Rio Grande, the Pecos River, and the Devils River.

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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 Amistad National Recreation Area (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 Amistad National Recreation Area, we monitor climate, groundwater, reservoir level, 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., WY2023 runs from October 2022 through September 2023). This web report presents the results of climate and water monitoring at Amistad National Recreation Area in WY2023.

Map of Amistad National Recreation Area showing 6 groundwater wells and one weather station in and around the park. Four wells and the weather station are along the reservoir, one is on the Devils River and one on the Pecos River.
Figure 1. Monitored weather station and groundwater wells at Amistad National Recreation Area.

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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), and 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

A National Oceanic and Atmospheric Administration Cooperative Observer Program (NOAA COOP) weather station (Amistad Dam #410225) has been operational at Amistad National Recreation Area since 1964 (Figure 1). This station provides a reliable, long-term climate dataset for analyses in this climate and water report. Data from this station are accessible through Climate Analyzer.

Two saucer shaped clouds over a desert hill.
Lenticular clouds at Amistad National Recreation Area.

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Results

Precipitation

Annual precipitation at Amistad Dam in WY2023 was 15.83″ (40.2 cm), 3.60″ (9.1 cm) less than the 1991–2020 annual average. Annual precipitation may be slightly underestimated because of 5 days of missing data in January. May received nearly twice the 1991–2020 average precipitation (Figure 2). Precipitation totals in October, November, March, and August were also above average. Substantially less precipitation occurred during December, February, July, and September, each receiving 8–14% of the 1991–2020 averages. Extreme daily rainfall events (≥ 1.00″; 2.54 cm) occurred on 6 days in WY2023 (Table 1), one more than the average annual frequency of 5.1 days.

Air Temperature

The mean annual maximum temperature at Amistad National Recreation Area in WY2023 was 83.4°F (28.5°C), 2.3°F (1.3°C) above the 1991–2020 average. The mean annual minimum temperature in WY2023 was 60.0°F (15.5°C), 1.9°F (1.1°C) above the 1991–2020 average. Mean monthly maximum and minimum temperatures in WY2023 differed by as much as 8.6°F (4.8°C; see January as an example) relative to the 1991–2020 monthly averages (Figure 2). Mean monthly maximum and minimum temperatures were variable relative to the 1991–2020 averages during the first part of the year (October–April). Temperatures from June through September were warmer than the 1991–2020 averages. Extremely hot temperatures (≥ 102.0°F; 38.9°C) occurred on 57 days in WY2023, over two and a half times the average frequency of 21.5 days. Extremely cold temperatures (≤ 35.0°F; 1.7°C) occurred on 17 days, slightly less than the average frequency of 20.1 days.

Climogram showing that overall max and min temperature averages for WY2023 from June through September are warmer than averages from 1991 to 2020.
Figure 2. Climogram showing monthly precipitation and mean maximum and minimum air temperatures in water year (WY) 2023 and the 1991–2020 averages at Amistad Dam weather station, Amistad National Recreation Area. 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 index for Amistad National Recreation Area indicates that WY2023 was drier than the 1991–2023 average for the third consectutive year from the perspective of both precipitation and potential evapotranspiration (Figure 3).

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

Figure 3. Bar graph showing that conditions during the three most recent water years are drier than the 1991 to 2023 average.
Figure 3. Reconnaissance drought index at Amistad Dam station in Amistad National Recreation Area, water years (WY) 1991–2023. Drought index calculations are relative to the time period selected (1990–2023). Choosing a different set of start/end points may produce different results. NA = insufficient data to generate reliable estimates. Data source: climateanalyzer.org.

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A large, rippling, blue lake lined by sheer rock cliffs topped by desert vegetation and a long bridge in the distance.
Amistad Reservoir

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Reservoir Level

The Amistad International Reservoir was formed by the construction of Amistad Dam between 1964 and 1969. Reservoir level is not a Chihuahuan Desert Network vital sign; however, it is included in this report because the reservoir level has implications for park resources throughout Amistad National Recreation Area, including groundwater and springs.

Methods

The International Boundary and Water Commission (IBWC) has operated a water level gage at Amistad Reservoir (International Amistad Reservoir Storage Station Number 08-4508.00) since 1968 when filling began. The gage is located at the downstream end of the reservoir. Every 15 minutes, the gage collects water level data, which are available from the IBWC and the Texas Water Development Board (TWDB).

Recent Findings 

In WY2023, mean reservoir level was 1,073.90 feet above mean sea level (ft amsl; 327.32 m amsl) with a range of 1,065.21 to 1,081.57 ft amsl (324.68 to 329.66 m amsl; Figure 4). During the entire year, reservoir level remained below the flood pool elevation of 1,140.4 ft amsl (347.59 m amsl; elevation of flood gates and emergency spillway) and the conservation pool elevation of 1,117.0 ft amsl (340.46 m amsl; maximum normal operating level, above which the storage is used to regulate floodwaters). Daily reservoir water level in WY2023 was on average 43.10 ft (13.14 m) below the conservation pool. Throughout the year, the reservoir ranged from 32–47% full. Throughout WY2023, the daily mean reservoir level was between the daily 1991–2020 average and minimum.

Figure 4. Line graph showing that the daily mean Amistad Reservoir level in WY2023 was between the 1991 and 2020 minimum and mean.
Figure 4. Daily Amistad Reservoir water level elevation in water year (WY) 2023 with the flood and conservation pool elevations and the 1991–2020 average daily mean, maximum, and minimum levels.

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Groundwater 

Groundwater is one of the most critical natural resources of the American Southwest. It provides drinking water, irrigates crops, and sustains rivers, streams, and springs throughout the region.  

Methods

Amistad National Recreation Area groundwater is monitored using six wells in or near the recreation area (Figure 1). Each well is monitored annually by the Texas Water Development Board (TWDB) and the data are available at the TWDB Database.

Results

Two wells could not be measured in WY2023: well 7122403 was not measured because we were unable to access the well site, and well 7140201 was not measured because of a possible well collapse. The other four wells were monitored in February. WY2023 groundwater levels increased in two wells compared to WY2022 measurements: wells 7033508 and 7140307. Both wells are near the south edge of the reservoir (Table 2, Figure 5). These results are consistent with a 12.46 ft (3.80 m) increase in reservoir level when groundwater was sampled in WY2023 compared to WY2022. Groundwater level in well 7017403 in WY2023 was nearly the same as the previous year, only 0.01 ft (0.003 m) lower. Well 7017403 is substantially higher than the reservoir level because it is up gradient of the reservoir, adjacent to the Devils River. Well 7033302 was the only well to show a large decrease from the previous year—a decrease of 18.83 ft (5.74 m). The cause of this drop is unclear, but nearby pumping could be responsible.

Figure 5. Line graph showing that water levels in four wells are lower than the reservoir water level and generally increase and decrease with the reservoir level. Water levels in two wells are higher than the reservoir and do not fluctuate as much.
Figure 5. Water level elevation in feet above mean sea level (ft amsl) in six groundwater monitoring wells and Amistad Reservoir at Amistad National Recreation Area, 1964–2023.

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Springs

Background

Springs, seeps, and tinajas (discrete 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., WY2023 runs from October 2022 through September 2023). WY2023 springs sampling at Amistad National Recreation Area occurred between 30 March and 03 April 2023. Water persistence is monitored continuously throughout the water year, but in this report we only present WY2023 persistence data up to the springs sampling visit date.

List of Springs

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

Big Satan Canyon Spring ǀ Dead Man's Canyon Spring ǀ Indian Springs Canyon Spring ǀ Mouth of the Pecos Spring

Figure 6. An elongated pool with algae covering approximately half of its surface, surrounded on three sides by white and grey rock dotted with patches of green vegetation.
Figure 6. Big Satan Canyon Spring at Amistad National Recreation Area, April 2023.

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Big Satan Canyon Spring

Big Satan Canyon Spring (Figure 6) is a rheocrene spring (a spring that emerges into one or more stream channels) located in Big Satan Canyon, a tributary to the Devil’s River. The spring emerges from multiple orifices created by small fissures in the bedrock-lined canyon and forms an elongated pool that has measured up to 32.5 m (106.6 ft) in length and is bounded on three sides by rock. The WY2023 visit occurred on 02 April 2023, and the spring was wetted (contained water). We did not collect data at Big Satan Canyon Spring in WY2022 because of logistical and time constraints.

Site Condition

In WY2023, we rated Big Satan Canyon Spring as slightly disturbed by drying because there were upland plant species in the vicinity of the springbrook (rated undisturbed to slightly disturbed in the past) and moderately disturbed by wildlife because of the presence of abundant droppings and evidence of grazing (rated undisturbed to slightly disturbed in the past). No other natural or human-caused disturbances were observed at Big Satan Canyon Spring in WY2023.

We did not observe the invasive non-native American bullfrog (Lithobates catesbeianus) at Big Satan Canyon Spring in WY2023. We observed five species of invasive non-native plants at the spring: scattered patches of giant reed (Arundo donax, not previously observed); a matrix of yellow bluestem (Bothriochloa ischaemum, scattered patches to evenly distributed patches found in 2018–2021); scattered patches of tree tobacco (Nicotiana glauca, 1–5 plants to scattered patches observed in 2017–2021); 1–5 sowthistle plants (Sonchus sp., not previously observed); and 1–5 lilac chastetree plants (Vitex agnus-castus, not previously observed).

We observed eight species of obligate/facultative wetland plants in WY2023: bluestem (Andropogon sp., a grass previously observed in 2019–2021); bulrush (Schoenoplectus sp., a sedge not previously observed); common buttonbush (Cephalanthus occidentalis, a shrub not previously observed); fogfruit (Phyla sp., a forb observed in 2018–2021); giant reed (Arundo donax; an invasive non-native grass not previously observed); mule-fat (Baccharis salicifolia, a shrub observed in 2021); rushes (Juncaceae, observed in 2018–2021); and spikerush (Eleocharis sp., a sedge observed in 2018–2021).

Water Quantity

Sensors are deployed and data are downloaded during our annual visit, which takes place in the middle of the water year; the dates of these visits are indicated by black diamonds in the persistence graph (Figure 7). A sensor malfunction resulted in only 31 days of measurements up to the WY2023 spring visit on 02 April 2023. The temperature sensor indicated that Big Satan Canyon Spring was wetted for 31 of 31 days (100%) measured. In prior water years, the spring was wetted 78.4–98.8% of the days measured across entire water years.

Water persistence graph showing Big Satan Canyon Spring was mostly wetted during the measured period (April 2021 to April 2023), except during the summer of 2022. The sensor malfunctioned in fall of 2022, resulting in missing data until the WY2023 visit.
Figure 7. Water persistence through 02 April 2023 in Big Satan Canyon Spring, Amistad National Recreation Area. White areas indicate dates before sensors were first deployed or after the WY2023 visit. Black diamonds indicate sensor deployment dates.

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Discharge measurements were last conducted at Big Satan Canyon Spring in WY2017, when discharge was estimated at 12.1 L/min (3.2 gal/min; Table 3). Since then, discharge has not been measurable at the site.

Wetted extent (a measure of length, width, and depth of surface water) was most recently assessed in WY2018 (Table 4), when the total brook length was 32.5 m (106.6 ft) and width averaged 11.4 m (37.4 ft). Depth measurements are not taken at Big Satan Canyon Spring because of safety and access concerns. We are evaluating alternative methods, such as GPS mapping, to systematically assess the wetted extent at this spring in the future.

Water Quality

Core water quality (Table 5) and water chemistry (Table 6) data were collected at the primary sampling location at the most upstream edge of the spring in WY2023. Levels of dissolved oxygen, specific conductivity, total dissolved solids, and pH were within the ranges of values previously recorded (2017–2021), while temperature was slightly lower. Alkalinity was within the range of past measurements. Calcium was higher than in the past, and chloride, magnesium, potassium, and sulphate were below prior measurements (2017–2018).

Big Satan Canyon Spring Data Tables

Figure 8. A hanging garden spring emerging from the side of a bedrock-lined drainage, forming pools at its base and contrasting with the white and grey limestone surroundings.
Figure 8. Dead Man’s Canyon Spring at Amistad National Recreation Area, April 2023.

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Dead Man's Canyon Spring

Dead Man’s Canyon Spring (Figure 8) is a hanging garden spring (a complex, multi-habitat spring that emerges along geologic contacts and seeps onto underlying walls). The spring is situated in Dead Man’s Canyon, a tributary of the Pecos River, where water seeps from the cliff face, trickling down the rocks and supporting a robust community of wetland plants clinging to the wall (Figure 9). Hidden grottos hold water and create pools behind the vegetation. The flow from this hanging garden converges with water from two other orifices inside the canyon bottom to form a channel that has extended over 100 m. The WY2023 visit occurred on 01 April 2023, and the spring was wetted (contained water).

Site Condition

In WY2023, we rated Dead Man’s Canyon Spring slightly disturbed by contemporary human use because of small amounts of trash in the immediate area (rated undisturbed to slightly disturbed in the past) and slightly disturbed by wildlife, with signs of browsing and droppings throughout the site (rated undisturbed to slightly disturbed in the past). No other natural or human-caused disturbances were observed at Dead Man’s Canyon Spring in WY2023.

We did not observe any invasive non-native American bullfrogs (Lithobates catesbeianus) at Dead Man’s Canyon Spring in WY2023. We observed four species of invasive non-native plants: evenly distributed patches of giant reed (Arundo donax; scattered patches observed in 2019–2022); scattered patches of yellow bluestem (Bothriochloa ischaemum; scattered patches observed in 2018–2019); 1–2 red brome plants (Bromus rubens; not previously observed); and scattered patches of Bermudagrass (Cynodon dactylon; scattered patches observed in 2017–2019).

We observed five species of obligate/facultative wetland plants at Dead Man’s Canyon Spring in WY2023: bulrush (Schoenoplectus sp., a sedge not previously observed); common buttonbush (Cephalanthus occidentalis, a shrub observed in 2019); giant reed (Arundo donax, a grass observed in 2018–2022); maidenhair fern (Adiantum sp., a fern observed in 2018–2022); and mule-fat (Baccharis salicifolia, a shrub observed in 2017–2019).

Figure 9. A person points to green vegetation on a cliff wall, where water seeps onto white rocks dotted with plants.
Figure 9. Close-up view of the hanging garden at Dead Man’s Canyon Spring at Amistad National Recreation Area, April 2023.

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Water Quantity

Sensors are deployed and data are downloaded during our annual visit, which takes place in the middle of the water year; the dates of these visits are indicated by black diamonds in the persistence graph (Figure 10). The temperature sensor indicated that Dead Man’s Canyon Spring was wetted for 183 of 183 days (100%) measured up to the WY2023 visit. In prior water years, the spring was wetted 54.1–100% of the days measured across entire water years.

Graph showing the spring was mostly wet from October 2017 to April 2023, except during summer 2022. Data are missing because of sensor loss or malfunction from the second half of WY2017 through the first half of WY2018 and from July 2020 to April 2022.
Figure 10. Water persistence through 01 April 2023 in Dead Man’s Canyon Spring, Amistad National Recreation Area. White areas indicate dates before sensors were first deployed or after the WY2023 visit. Black diamonds indicate sensor deployment dates.

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In WY2023, the estimated volumetric discharge was 4.3 ± 0.1 L/min (1.1 ± 0.03 gal/min), which falls within the historical range of 1.3 to 14.0 L/min at this sampling location where the flow converges below the hanging garden (2017–2022; Table 7).

Wetted extent was evaluated using a method for flowing water. In WY2023, the total springbrook length exceeded 100 m—the estimated total length was between 200–500 m (656–1,640 ft). In previous assessments, measured springbrook length ranged from 6.7 m (22.0 ft) to 31.8 m (104.3 ft). Width and depth within the first 100 m of springbrook length averaged 496.7 cm (195.6 in) and 10.5 cm (4.1 in), respectively (Table 8). Overall, the increases in length, width, and depth all greatly exceeded previous measurements, doubling (or more than doubling) past observations.

Water Quality

Core water quality (Table 9) and water chemistry (Table 10) data were collected at the primary sampling location, a pool at the base of the hanging garden. In WY2023, levels of dissolved oxygen, specific conductivity, and total dissolved solids were within previous value ranges (2017–2022), while water temperature was below and pH was slightly above past values. Calcium, magnesium, potassium, and sulphate values were consistent with prior years, while alkalinity was below and chloride was above previous measurements.

Dead Man's Canyon Spring Data Tables

Two people sitting and one person standing on the edge of a stream pointing at the orifice of the spring that emerges as moderate flow in a stream channel lined with cobbles. Two limestone ledges are seen along one side of the stream.
Figure 11. Orifice H at Indian Springs Canyon Spring in April 2023, Amistad National Recreation Area.

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Indian Springs Canyon Spring

Indian Springs Canyon Spring (Figure 11) is a rheocrene spring (a spring that emerges into one or more stream channels) in Indian Springs Canyon. The spring has a strong hydrologic connectivity to the water level of Amistad Reservoir, and as a result, the emergence location for this spring is highly variable. In WY2018, WY2019, and WY2020, the spring emerged 500 m upstream of the canyon’s mouth (orifice A; Figure 12). In WY2022, the spring emerged at the mouth of the canyon (orifice G), and in WY2023, it emerged about 100 m upstream of the canyon’s mouth (orifice H). Spring characteristics vary depending on emergence location, but the spring typically forms standing, elongated pools or a stream slowly flowing over cobble and bedrock. The springbrook has measured over 100 m in length in previous years. The WY2023 visit occurred on 03 April 2023, and the spring was wetted (contained water) at orifice H, but all other previously named spring orifices were dry.

A dry streambed with white, exposed bedrock along the bottom and side, with shrubs lining the banks.
Figure 12. Orifice A at Indian Springs Canyon Spring, dry at the time of the WY2023 visit.

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Site Condition

Site condition was assessed around orifice H, about 100 m upstream from the mouth of Indian Springs Canyon. In WY2023, We rated Indian Springs Canyon Spring moderately disturbed by contemporary human use, with the presence of trash (cans, shoes, etc.) and social trails (rated undisturbed to slightly disturbed in the past); moderately disturbed by drying because there was a dearth of obligate wetland species and the riparian area was choked by invasive plants (rated undisturbed to highly disturbed in the past); and moderately disturbed by wildlife based on tracks and sightings (rated undisturbed in the past). No other natural or human-caused disturbances were observed at Indian Springs Canyon Spring in WY2023.

We did not observe the invasive non-native American bullfrog (Lithobates catesbeianus) at Indian Springs Canyon Spring in WY2023. We observed six species of invasive non-native plants: evenly distributed patches of seaside petunia (Calibrachoa parviflora, not previously observed); 1–5 straggler daisy plants (Calyptocarpus vialis, not previously observed); scattered patches of bermudagrass (Cynodon dactylon, 1–5 plants to a matrix observed in 2018–2022); 1–5 little bur-clover plants (Medicago minima, not previously observed); scattered patches of tree tobacco (Nicotiana glauca, scattered patches observed in 2022); and a matrix of lilac chastetree (Vitex agnus-castus, 1–5 plants to scattered patches observed in 2017–2022).

We did not observe any obligate/facultative wetland plants at Indian Springs Canyon Spring in WY2023.

Water Quantity

Sensors are deployed and data are downloaded during our annual visit, which takes place in the middle of the water year; the dates of these visits are indicated by black diamonds in the persistence graph (Figure 13). From 2018 to 2023, water persistence was monitored at orifice A. The temperature sensor deployed in April 2022 was not found during the WY2023 visit, so persistence data are missing for WY2023. In prior water years, the spring was wetted 3.6–86.7% of the days measured.

Graph showing the spring stayed mostly wet between April 2019 and February 2020 but has otherwise been mostly dry with intermittent wet periods since monitoring began in WY2018. Data are missing from April 2022 to April 2023 because of sensor loss.
Figure 13. Water persistence through 03 April 2023 at orifice A in Indian Springs Canyon Spring, Amistad National Recreation Area. White areas indicate dates before sensors were first deployed or after the WY2023 visit. Black diamonds indicate sensor deployment dates.

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Discharge was not measurable at Indian Springs Canyon Spring in WY2023 because of a lack of surface flow. No prior discharge measurements are available.

Wetted extent was evaluated using a method for flowing water. The total springbrook length was 54.4 m (178.4 ft). In the past, measured springbrook length in WY2023 ranged from 27.0 m (88.6 ft) to an estimated 100–200 m (328–656 ft). Width and depth along the springbrook averaged 5.6 m (18.3 ft) and 19.6 cm (7.7 in), respectively. The springbrook in WY2023 was within the range of previous length measurements, but it was slightly wider and deeper on average (Table 11).

Water Quality

Core water quality (Table 12) and water chemistry (Table 13) data were collected at orifice H (sampling location 008). Values from WY2022, taken at orifice G (sampling location 007) are presented for context, but continued monitoring is needed before meaningful comparisons can be made.

Indian Springs Canyon Spring Data Tables

A person points to a dry area on the ground surrounded by large gray boulders and bright green vegetation.
Figure 14. Mouth of the Pecos Spring at Amistad National Recreation Area, March 2023. NPS.

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Mouth of the Pecos Spring

Mouth of the Pecos Spring (Figure 14) is a limnocrene spring (a spring that emerges to form one or more stagnant pools) located in a side canyon of the Lower Pecos River, just upstream from its confluence with Amistad Reservoir. When flowing, the spring emerges from two orifices to form small pools surrounded by boulders in the canyon bottom before dispersing into a marshy area populated by cattails. The WY2023 visit occurred on 30 March 2023, and the spring was dry. We did not collect data at Mouth of the Pecos Spring in WY2022 because of logistical and time constraints.

Site Condition

In WY2023, we rated Mouth of the Pecos Spring slightly disturbed by contemporary human use because of trash along the banks (rated slightly disturbed in the past); slightly disturbed by feral animals with horse/burro manure in the streambed (rated undisturbed to slightly disturbed in the past); slightly disturbed by wildlife because of tracks and scat (rated undisturbed to slightly disturbed in the past); moderately disturbed by roads/OHVs based on a parking area that is located less than 100 m from the site, though there was minimal to no impact on vegetation/soils (rated undisturbed to slightly disturbed in the past); and highly disturbed by drying since the spring was dry, but some wetland obligates were still present (rated undisturbed to highly disturbed in the past). No other natural or human-caused disturbances were observed at Mouth of the Pecos Spring in WY2023.

We did not observe the invasive non-native American bullfrog (Lithobates catesbeianus) at Mouth of the Pecos Spring in WY2023. We observed three species of invasive non-native plants: a matrix of giant reed (Arundo donax, evenly distributed patches to a matrix observed in 2018–2021); scattered patches of bermudagrass (Cynodon dactylon, scattered patches to a matrix observed in 2017–2021); and scattered patches of tamarisk (Tamarix sp, not previously observed).

We observed four species of obligate/facultative wetland plants at Mouth of the Pecos Spring in WY2023: cattail (Typhaceae, a grass observed in 2017–2021); giant reed (Arundo donax, a grass observed in 2018–2021); mule-fat (Baccharis salicifolia, a shrub observed in 2017–2021); and tamarisk (Tamarix sp., a tree/shrub observed in 2018).

Water Quantity

Sensors are deployed and data are downloaded during our annual visit, which takes place in the middle of the water year; the dates of these visits are indicated by black diamonds in the persistence graph (Figure 15). The temperature sensor indicated that Mouth of the Pecos Spring was wetted for 46 of 52 days (88.5%) measured up to the WY2023 visit. In prior water years, the spring was wetted 80.8–100% of the days measured.

Area chart showing the spring was wet from mid-WY2017 to mid-WY2021, before intermittent dry periods occurred in spring and summer of WY2021 and WY2022. Data are missing for about 3 months in WY2017 and about 4 months leading up to the WY2023 visit.
Figure 15. Water persistence through 30 March 2023 in Mouth of the Pecos Spring, Amistad National Recreation Area. White areas indicate dates before sensors were first deployed or after the WY2023 visit. Black diamonds indicate sensor deployment dates.

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Discharge was not measurable in WY2023 since the spring was dry at the time of the visit. Discharge estimates are available for one prior year (2019) when it was estimated at 23.1 L/min (6.10 gal/min; Table 14).

Wetted extent (a measure of length, width, and depth of surface water) was not measurable in WY2023 since the spring was dry, but wetted extent data for WY2019 are included in Table 15.

Water Quality

Core water quality (Table 16) and water chemistry (Table 17) data were not collected in WY2023 since the spring was dry. We report previous (2018–2019) values in the tables.

Mouth of the Pecos Spring Data Tables

Report Citation

Authors: Kara Raymond, Susan Singley

Raymond, K., and S. Singley. 2025. Climate and Water Monitoring at Amistad National Recreation Area: Water Year 2023. Chihuahuan Desert Network, National Park Service, Las Cruces, New Mexico.

Past Reports

Water Year 2022 Web Report
Water Year 2021 Web Report
Water Year 2018 Full Report

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Amistad National Recreation Area

Last updated: August 7, 2025