July 30, 2025

Water clarity was measured at eight locations in the Providence River and Seekonk River estuaries on July 30, 2025. In the five days prior to the survey, 1.91 inches of precipitation were recorded at TF Green. Secchi depth averaged 2.2 meters. The lowest clarity this week (1.5 meters) was measured at Phillipsdale Landing and Pawtuxet Cove, while the greatest clarity (3.7 meters) was measured at Point Street Bridge. There was no clear north-to-south gradient in water clarity among the sites this week. Overall, water clarity remained approximately the same from the previous measurements (data collected July 23, 2025).

May 26 – June 1, 2025

Phillipsdale Landing

Overall, water quality at Phillipsdale Landing was good this week. Weather conditions were slightly dryer this week than previous weeks, with a total of 0.53 inches recorded at T.F. Green, and the majority of rainfall occurring on the 31st.  The Blackstone River flow decreased throughout the week, but remained above the 20-year daily median for the entire week. Salinity at the surface averaged 4.4 ppt and ranged from 1.4 ppt to 15.6 ppt. At the bottom, salinity averaged 11.1 ppt and ranged from 2.0 ppt to 26.4 ppt. Temperatures this week averaged 17.0 °C at the surface and 16.0 °C at the bottom. Surface temperatures ranged from 13.2 °C to 19.5 °C, while bottom temperatures ranged from 12.6 °C to 19.3 °C.

Dissolved oxygen (DO) at Phillipsdale Landing remained above the hypoxia threshold (i.e., DO >2.9 mg/L) throughout the week. Surface DO averaged 8.8 mg/L and ranged from 6.8 -10.4 mg/L. Bottom water DO concentration averaged 7.8 mg/L and ranged from 5.5 mg/L to 10.4 mg/L. Chlorophyll was low, averaging 1.5 ug/L at the surface and 1.8 ug/L at the bottom. Maximum surface chlorophyll readings reached 4.4 ug/L in the early morning of May 31st. Please note that tidal fluctuations and Blackstone River flows greatly influence water column salinity, temperature, and DO at this location.

Bullock Reach

The Bullock Reach Buoy remains out of the water for the winter.  EM will coordinate with RIDEM to redeploy the buoy in late spring-early summer.

May 19 – May 25, 2025

Phillipsdale Landing

Overall, water quality at Phillipsdale Landing was fair to good this week. Weather conditions were wet this week, with a total of 2.31 inches recorded at T.F. Green, and the majority of rainfall occurring on the 26th.  The Blackstone River flow peaked on the 23rd and 24th, but remained above the 20-year daily median for the entire week. Salinity at the surface averaged 5.4 ppt and ranged from 0.3 ppt to 12.7 ppt. At the bottom, salinity averaged 12.3 ppt and ranged from 0.1 ppt to 37.2 ppt; however, the salinity data for the first part of the week also exhibits some anomalous behavior, and may be tied to a sensor malfunction. Temperatures this week averaged 14.6 °C at the surface and 13.7 °C at the bottom. Surface temperatures ranged from 12.0 °C to 19.1 °C, while bottom temperatures ranged from 12.2 °C to 18.0 °C.

Dissolved oxygen (DO) at Phillipsdale Landing remained above the hypoxia threshold (i.e., DO >2.9 mg/L) throughout the week. Surface DO averaged 9.2 mg/L and ranged from 7.1 -11.4 mg/L. Bottom water DO concentration averaged 7.6 mg/L and ranged from 3.4 mg/L to 11.3 mg/L. Chlorophyll was low, averaging 1.1 ug/L at the surface and 1.5 ug/L at the bottom. Maximum surface chlorophyll readings reached 2.4 ug/L. Please note that tidal fluctuations and Blackstone River flows greatly influence water column salinity, temperature, and DO at this location.

The bottom sonde had a malfunctioning depth sensor, thus no depth data is available for the bottom sonde until the sondes were swapped out on May 20th.

Bullock Reach

The Bullock Reach Buoy remains out of the water for the winter.  EM will coordinate with RIDEM to redeploy the buoy in late spring-early summer.

​May 12 – May 18, 2025

Phillipsdale Landing

Overall, water quality at Phillipsdale Landing was fair to good this week. Weather conditions were wet this week, with a total of 1.38 inches recorded at T.F. Green, and the majority of rainfall occurring on the 15th.  The Blackstone River flow peaked on the 16th and remained above the 20-year daily median for the entire week. Salinity at the surface averaged 1.8 ppt and ranged from 0.4 ppt to 4.2 ppt. At the bottom, salinity averaged 9.1 ppt and ranged from 0.0 ppt to 32.8 ppt; however, the salinity data for the first part of the week also exhibits some anomalous behavior, and may be tied to a sensor malfunction. Temperatures this week averaged 18.2 °C at the surface and 16.1 °C at the bottom. Surface temperatures ranged from 14.7 °C to 20.6 °C, while bottom temperatures ranged from 11.8 °C to 20.1 °C.

Dissolved oxygen (DO) at Phillipsdale Landing remained above the hypoxia threshold (i.e., DO >2.9 mg/L) throughout the week. Surface DO averaged 9.0 mg/L and ranged from 7.8 -10.4 mg/L. Bottom water DO concentration averaged 7.1 mg/L and ranged from 3.9 mg/L to 9.9 mg/L. Chlorophyll was low, averaging 0.9 ug/L at the surface and 2.7 ug/L at the bottom. Maximum surface chlorophyll readings reached 3.7 ug/L, recorded on the afternoon of May 12th. Please note that tidal fluctuations and Blackstone River flows greatly influence water column salinity, temperature, and DO at this location.

The bottom sonde had a malfunctioning depth sensor this week, thus no depth data is available for the bottom sonde. The salinity data for this week also exhibits some anomalous behavior, and may have been malfunctioning.

Bullock Reach

The Bullock Reach Buoy remains out of the water for the winter.  EM will coordinate with RIDEM to redeploy the buoy in late spring-early summer.

​May 5- May 11, 2025

Phillipsdale Landing

The Phillipsdale Landing sondes were deployed for the season on May 6, 2025. Overall, water quality at Phillipsdale Landing was fair to good this week. Weather conditions were wet this week, with a total of 3.51 inches recorded at T.F. Green, and the majority of rainfall occurring on the 5th, 6th, and 9th.  The Blackstone River flow increased on the 5th and remained above the 20-year daily median for the remainder of the week. Salinity at the surface averaged 2.2 ppt and ranged from 0.5 ppt to 6.2 ppt. At the bottom, salinity averaged 11.3 ppt and ranged from 0.0 ppt to 28.4 ppt. Temperatures this week averaged 16.9 °C at the surface and 15.0 °C at the bottom. Surface temperatures ranged from 14.2 °C to 19.6 °C, while bottom temperatures ranged from 11.8 °C to 18.3 °C.

Dissolved oxygen (DO) at Phillipsdale Landing remained above the hypoxia threshold (i.e., DO >2.9 mg/L) throughout the week. Surface DO averaged 9.3 mg/L and ranged from 7.9 -10.6 mg/L. Bottom water DO concentration averaged 7.1 mg/L and ranged from 3.9 mg/L to 10.3 mg/L. Chlorophyll was low, averaging 2.11 ug/L at the surface and 4.5 ug/L at the bottom. Maximum surface chlorophyll readings reached 20.8 ug/L, recorded on the morning of May 6th. Please note that tidal fluctuations and Blackstone River flows greatly influence water column salinity, temperature, and DO at this location.

The bottom sonde had a malfunctioning depth sensor this week, thus no depth data is available for the bottom sonde.

Bullock Reach

The Bullock Reach Buoy remains out of the water for the winter.  EM will coordinate with RIDEM to redeploy the buoy in late spring-early summer.

July 23, 2025

Water clarity was measured at seven locations in the Providence River and Seekonk River estuaries on July 23, 2025. In the five days prior to the survey, trace amounts of precipitation were recorded at TF Green. Secchi depth averaged 2.0 meters. The lowest clarity this week (1.7 meters) was measured at Edgewood Yacht Club and Pomham Rocks, while the greatest clarity (2.5 meters) was measured at Bullock’s Reach. There was no clear north-to-south gradient in water clarity among the sites this week. Overall, water clarity remained approximately the same from the previous measurements (data collected July 16, 2025).

 June 25, 2025

Nutrient samples were collected from seven river stations and seven bay stations on June 25th. All bay stations were sampled at the surface and bottom. In the five days prior to sampling, there were 0.01 inches of precipitation recorded at T.F. Green. 

Among the river stations sampled, the highest total nitrogen (TN) was observed at Blackstone River @ Stateline (917 ppb). The highest total dissolved nitrogen (TDN) and dissolved inorganic nitrogen (DIN) were observed at Woonasquatucket River @ Valley St. (TDN = 946 ppb, DIN = 734.5, average of duplicates). The lowest TN, TDN and DIN were observed at Pawtuxet River @ Broad St. (TN = 587 ppb, TDN = 349 ppb, DIN = 41.9 ppb).

Among the bay stations sampled, the highest surface TN was observed at Phillipsdale Landing (973 ppb). The highest TDN and DIN were observed at Pawtuxet Cove (TDN = 546 ppb, DIN = 319.7 ppb). The lowest surface TN was observed at India Point Park (468 ppb). The lowest surface TDN was observed at Bullock Reach Buoy (151 ppb). The lowest surface DIN was observed at five of seven bay stations (13 ppb, reflecting minimum detection limits for DIN).

The next scheduled sampling date is July 8th, 2025.​

December 9 – 15, 2024

Phillipsdale Landing

The sondes were retrieved this week on December 9th to finish up the 2024 season. Due to the Phillipsdale Landing sondes being removed, we only have data from the morning of December 9th. The sonde removal occurred before the rain reported that day (0.37 inches recorded at TF Green). Blackstone River flows remained stable and below the 20-year median statistic for the morning. Salinity at the surface averaged 22.1 ppt and ranged from 16.9 ppt to 24.6 ppt. At the bottom, salinity averaged 25.3 ppt and ranged from 20.2 ppt to 26.8 ppt. Temperatures averaged 6.4°C at the surface and 6.9°C at the bottom. Surface temperatures ranged from 5.6°C to 6.8°C, while bottom temperatures ranged from 6.1°C to 7.1°C.

Dissolved oxygen (DO) at Phillipsdale Landing remained above the hypoxia threshold of 2.9 mg/L at all depths throughout the week. Surface DO averaged 9.6 mg/L and ranged 9.0-10.4 mg/L. Bottom water DO concentration averaged 9.0 mg/L and ranged from 8.7 mg/L to 10.1 mg/L. Chlorophyll readings increased since last week, averaging 10.9 µg/L at the surface and 6.7 µg/L at the bottom. Maximum chlorophyll at the surface reached 21.7 µg/L at 8:01 December 9th. Please note that tidal fluctuations and Blackstone River flows greatly influence water column salinity, temperature, and DO at this location. Phillipsdale Landing sonde will be deployed again in the spring for the 2025 monitoring season.

Bullock Reach 

Bullock Reach sondes were removed on November 18th and will be deployed again in the spring for the 2025 monitoring season.

December 2 – 8, 2024

Phillipsdale Landing

Overall, the water quality at Phillipsdale Landing was good this week. Weather conditions included sporadic rain events, with 0.62 inches of precipitation recorded at T.F. Green. The Blackstone River flow fluctuated through the week in response to rain but remained below the 20-year daily median throughout the week. Surface salinity averaged 21.4 ppt and ranged from 11.7 ppt to 26.4 ppt. At the bottom, salinity averaged 25.3 ppt and ranged from 12.4 ppt to 29.0 ppt. Temperatures decreased this week, averaging 7.2°C at the surface and ranging 3.7°C – 9.2°C. At the bottom, temperatures averaged 8.1°C and ranged 4.7°C – 9.5°C.

Dissolved oxygen (DO) at Phillipsdale Landing remained above the hypoxia threshold of 2.9 mg/L at all depths throughout the week. Surface DO averaged 9.6 mg/L and ranged 8.0-11.7 mg/L. Bottom water DO concentration averaged 8.7 mg/L and ranged from 7.5 mg/L to 10.9 mg/L. Chlorophyll readings increased from last week, averaging 6.3 µg/L at the surface and 5.8 µg/L at the bottom. Maximum chlorophyll at the surface reached 50.7 µg/L on the morning of December 8th. Please note that tidal fluctuations and Blackstone River flows greatly influence water column salinity, temperature, and DO at this location. 

Bullock Reach 

Bullock Reach sondes were removed on November 18th and will be deployed again in the spring for the 2025 monitoring season.

November 25 – December 1, 2024

Phillipsdale Landing

Overall, the water quality at Phillipsdale Landing was good this week. Weather conditions included sporadic rain events, with 0.76 inches of precipitation recorded at T.F. Green. The Blackstone River flow fluctuated throughout the week in response to rain. Surface salinity averaged 18.9 ppt and ranged from 6.6 ppt to 25.6 ppt. At the bottom, salinity averaged 26.5 ppt and ranged from 14.5 ppt to 29.1 ppt. Temperatures continued to decrease this week, averaging 9.1°C at the surface and ranging 5.4°C – 10.3°C. At the bottom, temperatures averaged 10.1°C and ranged 8.6°C – 10.8°C.

Dissolved oxygen (DO) at Phillipsdale Landing remained above the hypoxia threshold (i.e., DO >2.9 mg/L) throughout the week. Surface DO averaged 8.5 mg/L and ranged 5.8-10.6 mg/L. Bottom water DO concentration averaged 7.5 mg/L and ranged from 6.4 mg/L to 8.9 mg/L. Chlorophyll readings increased from last week, averaging 2.5 µg/L at the surface and 2.3 µg/L at the bottom. Maximum chlorophyll at the surface reached 25.4 µg/L on the afternoon of December 1st. Please note that tidal fluctuations and Blackstone River flows greatly influence water column salinity, temperature, and DO at this location. 

Bullock Reach 

Bullock Reach sondes were removed on November 18th and will be deployed again in the spring for the 2025 monitoring season.

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