High-frequency Monitoring of Delta Island Drainage Waters Active
Land reclamation has transformed the Sacramento-San Joaquin Delta
The landscape of the Delta has gone from a network of shifting waterways and tidal marshland to channels and islands fixed in position by hardened levees.
Island Drainage
Water collected in networks of drainage ditches is routed to where it can be pumped off the islands and back into adjacent channels.
Impacts on water quality and the aquatic ecosystem
Water returned to Delta waterways by pumping may contain carbon, nutrients, phytoplankton, trace elements, and contaminants.
From the second half of the 19th century, land reclamation has transformed the Sacramento-San Joaquin Delta (Delta). The landscape of the Delta has gone from a network of shifting waterways and tidal marshland to channels and islands fixed in position by hardened levees.
Decades of agricultural practices have caused Delta islands to subside to levels well below those of surrounding channels. This causes the water entering, either by levee seepage, precipitation, or irrigation, to accumulate in island interiors at rates faster than it is removed by evaporation and transpiration.
To both prevent flooding and to maintain lower water levels on subsided Delta islands in order for crops to grow, accumulated water is collected in networks of drainage ditches and then routed to where it can be pumped off the islands and back into adjacent channels. This is practice is called island drainage.
The Problem
This continuous water cycling through the Delta by island drainage affects both the aquatic and terrestrial portions of the Delta environment. The evaporation and transpiration of water entering Delta islands via seepage and deliberate irrigation, results in the net depletion of water from Delta waterways. And water that is returned to Delta waterways by pumping may contain carbon, nutrients, phytoplankton, trace elements, and contaminants. This affects water quality and how the aquatic ecosystem functions.
Water pumped from Delta islands can also result in the loss of carbon, including dissolved organic carbon (DOC), dissolved inorganic carbon (DIC), and particulate organic carbon (POC). This is important to limit. Carbon losses from DOC alone may comprise more than 10% of whole ecosystem carbon budgets. These losses may also be contributing to further island mass loss and subsidence.
What is Being Done
Efforts are being made to combat subsidence and greenhouse gas emissions and to restore the Delta island ecosystems by shifting cultivation patterns from dry soil crops, such as corn and wheat, to flooded soil crops, such as rice. Work to convert less productive agricultural land to managed wetland habitats is also being undertaken. A carbon credit system to counteract the loss of agricultural revenue by these measures is also being evaluated. Studying the impact of restoration on Delta island water cycling and, specifically, on island drainage water quality and carbon export, will be important in determining its effectiveness.
Advances in sensor and data handling technology have enabled continuous and autonomous high-frequency measurement of an increasing number of water quality parameters. These range from basic field parameters (temperature, specific conductivity, turbidity, pH, dissolved oxygen) to advanced water quality parameters (nitrate, dissolved organic matter, chlorophyll, phycocyanin). The USGS California Water Science Center has established a network of water quality parameter sensors at numerous locations throughout the Delta. The high-frequency data from this network have yielded insight into water quality and biogeochemical processes in the time-sensitive Delta environment far beyond that available with traditional episodic discrete sampling approaches. Continuous and autonomous high-frequency measurement are ideal for characterizing Delta island drainage water quality, which is thought to be highly variable in response to natural and human-caused mechanisms.
Science Plan
The focus of this study is to establish and maintain continuous high-frequency water quality monitoring of Delta island drainage on two islands: Twitchell Island and Staten Island. Two monitoring stations have been established on Staten Island and one monitoring station has been established on Twitchell Island. These islands were chosen because of their contrasting land use and management practices. Both Twitchell Island and Staten Island are located in the heavily subsided central portion of the Delta.
Continuous Monitoring Station Links:
| Staten Island East Pump Station (SIE): USGS 380924121301901 STATEN ISLAND NR TERMINOUS CA |
| Staten Island South Pump Station (SIS): USGS 380711121323401 STATEN ISLAND DRAIN NR TERMINOUS CA |
| Twitchell Island Pump Station: (TWI): USGS 380548121390501 TWITCHELL ISLAND DR A PUMP STATION NR RIO VISTA CA |
Land use on Twitchell Island is increasingly devoted to wetland restoration and flooded soil agriculture projects, with a 15-acre pilot scale wetland completed in 1997, a 600-acre rice research facility completed in 2008, and a 750-acre restored wetland completed in 2013.
In contrast, land use on Staten Island is primarily devoted to dry soil row crops whose fields are flooded after harvest to provide seasonal migratory bird habitat. However, Staten Island land use is currently changing. Efforts are underway to convert a part of the island to rice cultivation. A study has also been completed assessing the conversion of a 1000-acre portion of the island to restored wetland habitat.
Continuous high-frequency water quality monitoring of island drainage on these islands will provide insight into how both current differences and future changes in land use and management practices are impacting and will affect water quality at these two contrasting locations.
References:
Kraus, T. E. C., O'Donnell, K., Downing, B. D., Burau, J. R., and Bergamaschi, B. A. (2017b). Using Paired In Situ High Frequency Nitrate Measurements to Better Understand Controls on Nitrate Concentrations and Estimate Nitrification Rates in a Wastewater-Impacted River. Water Resources Research, 53(10), 8423-8442. https://doi.org/10.1002/2017WR020670
Downing, B.D., Bergamaschi, B.A., and Kraus, T.E.C., (2017). Synthesis of data from high-frequency nutrient and associated biogeochemical monitoring for the Sacramento–San Joaquin Delta, northern California: U.S. Geological Survey Scientific Investigations Report 2017–5066, 28 p., https://doi.org/10.3133/sir20175066.
Kraus, T.E.C, Bergamaschi, B.A. and Downing, B.D. (2017a) An introduction to high-frequency nutrient and biogeochemical monitoring for the Sacramento–San Joaquin Delta, northern California, USGS Scientific Investigations Report 2017–5071. US Geological Survey, p. 41. https://doi.org/10.3133/sir20175071
Pellerin, B. A., Stauffer, B. A., Young, D. A., Sullivan, D. J., Bricker, S. B., Walbridge, M. R., … Shaw, D. M. (2016). Emerging tools for continuous nutrient monitoring networks: Sensors advancing science and water resources protection. Journal of the American Water Resources Association, 52, 993–1008. https://doi.org/10.1111/1752-688.1238
Ingebritsen, S. E., Ikehara, M. E., Galloway, D. L., and Jones, D. R. (2000). Delta subsidence in California: the sinking heart of the state. US Department of the Interior, US Geological Survey. https://doi.org/10.3133/fs00500
CM Richardson, JK Fackrell, TEC Kraus, M Young, A Paytan (2022). Nutrient and Trace Element Contributions from Drained Islands in the Sacramento–San Joaquin Delta, California
San Francisco Estuary and Watershed Science 20 (2) https://doi.org/10.15447/sfews.2022v20iss2art5
CM Richardson, JK Fackrell, TEC Kraus, MB Young, A Paytan (2020). Lateral Carbon Exports From Drained Peatlands: An Understudied Carbon Pathway in the Sacramento‐San Joaquin Delta, California
Journal of Geophysical Research: Biogeosciences 125 (12), e2020JG005883 https://doi.org/10.1029/2020JG005883
Flow and Water Quality Data in the San Francisco Estuary
From the second half of the 19th century, land reclamation has transformed the Sacramento-San Joaquin Delta (Delta). The landscape of the Delta has gone from a network of shifting waterways and tidal marshland to channels and islands fixed in position by hardened levees.
Decades of agricultural practices have caused Delta islands to subside to levels well below those of surrounding channels. This causes the water entering, either by levee seepage, precipitation, or irrigation, to accumulate in island interiors at rates faster than it is removed by evaporation and transpiration.
To both prevent flooding and to maintain lower water levels on subsided Delta islands in order for crops to grow, accumulated water is collected in networks of drainage ditches and then routed to where it can be pumped off the islands and back into adjacent channels. This is practice is called island drainage.
The Problem
This continuous water cycling through the Delta by island drainage affects both the aquatic and terrestrial portions of the Delta environment. The evaporation and transpiration of water entering Delta islands via seepage and deliberate irrigation, results in the net depletion of water from Delta waterways. And water that is returned to Delta waterways by pumping may contain carbon, nutrients, phytoplankton, trace elements, and contaminants. This affects water quality and how the aquatic ecosystem functions.
Water pumped from Delta islands can also result in the loss of carbon, including dissolved organic carbon (DOC), dissolved inorganic carbon (DIC), and particulate organic carbon (POC). This is important to limit. Carbon losses from DOC alone may comprise more than 10% of whole ecosystem carbon budgets. These losses may also be contributing to further island mass loss and subsidence.
What is Being Done
Efforts are being made to combat subsidence and greenhouse gas emissions and to restore the Delta island ecosystems by shifting cultivation patterns from dry soil crops, such as corn and wheat, to flooded soil crops, such as rice. Work to convert less productive agricultural land to managed wetland habitats is also being undertaken. A carbon credit system to counteract the loss of agricultural revenue by these measures is also being evaluated. Studying the impact of restoration on Delta island water cycling and, specifically, on island drainage water quality and carbon export, will be important in determining its effectiveness.
Advances in sensor and data handling technology have enabled continuous and autonomous high-frequency measurement of an increasing number of water quality parameters. These range from basic field parameters (temperature, specific conductivity, turbidity, pH, dissolved oxygen) to advanced water quality parameters (nitrate, dissolved organic matter, chlorophyll, phycocyanin). The USGS California Water Science Center has established a network of water quality parameter sensors at numerous locations throughout the Delta. The high-frequency data from this network have yielded insight into water quality and biogeochemical processes in the time-sensitive Delta environment far beyond that available with traditional episodic discrete sampling approaches. Continuous and autonomous high-frequency measurement are ideal for characterizing Delta island drainage water quality, which is thought to be highly variable in response to natural and human-caused mechanisms.
Science Plan
The focus of this study is to establish and maintain continuous high-frequency water quality monitoring of Delta island drainage on two islands: Twitchell Island and Staten Island. Two monitoring stations have been established on Staten Island and one monitoring station has been established on Twitchell Island. These islands were chosen because of their contrasting land use and management practices. Both Twitchell Island and Staten Island are located in the heavily subsided central portion of the Delta.
Continuous Monitoring Station Links:
| Staten Island East Pump Station (SIE): USGS 380924121301901 STATEN ISLAND NR TERMINOUS CA |
| Staten Island South Pump Station (SIS): USGS 380711121323401 STATEN ISLAND DRAIN NR TERMINOUS CA |
| Twitchell Island Pump Station: (TWI): USGS 380548121390501 TWITCHELL ISLAND DR A PUMP STATION NR RIO VISTA CA |
Land use on Twitchell Island is increasingly devoted to wetland restoration and flooded soil agriculture projects, with a 15-acre pilot scale wetland completed in 1997, a 600-acre rice research facility completed in 2008, and a 750-acre restored wetland completed in 2013.
In contrast, land use on Staten Island is primarily devoted to dry soil row crops whose fields are flooded after harvest to provide seasonal migratory bird habitat. However, Staten Island land use is currently changing. Efforts are underway to convert a part of the island to rice cultivation. A study has also been completed assessing the conversion of a 1000-acre portion of the island to restored wetland habitat.
Continuous high-frequency water quality monitoring of island drainage on these islands will provide insight into how both current differences and future changes in land use and management practices are impacting and will affect water quality at these two contrasting locations.
References:
Kraus, T. E. C., O'Donnell, K., Downing, B. D., Burau, J. R., and Bergamaschi, B. A. (2017b). Using Paired In Situ High Frequency Nitrate Measurements to Better Understand Controls on Nitrate Concentrations and Estimate Nitrification Rates in a Wastewater-Impacted River. Water Resources Research, 53(10), 8423-8442. https://doi.org/10.1002/2017WR020670
Downing, B.D., Bergamaschi, B.A., and Kraus, T.E.C., (2017). Synthesis of data from high-frequency nutrient and associated biogeochemical monitoring for the Sacramento–San Joaquin Delta, northern California: U.S. Geological Survey Scientific Investigations Report 2017–5066, 28 p., https://doi.org/10.3133/sir20175066.
Kraus, T.E.C, Bergamaschi, B.A. and Downing, B.D. (2017a) An introduction to high-frequency nutrient and biogeochemical monitoring for the Sacramento–San Joaquin Delta, northern California, USGS Scientific Investigations Report 2017–5071. US Geological Survey, p. 41. https://doi.org/10.3133/sir20175071
Pellerin, B. A., Stauffer, B. A., Young, D. A., Sullivan, D. J., Bricker, S. B., Walbridge, M. R., … Shaw, D. M. (2016). Emerging tools for continuous nutrient monitoring networks: Sensors advancing science and water resources protection. Journal of the American Water Resources Association, 52, 993–1008. https://doi.org/10.1111/1752-688.1238
Ingebritsen, S. E., Ikehara, M. E., Galloway, D. L., and Jones, D. R. (2000). Delta subsidence in California: the sinking heart of the state. US Department of the Interior, US Geological Survey. https://doi.org/10.3133/fs00500
CM Richardson, JK Fackrell, TEC Kraus, M Young, A Paytan (2022). Nutrient and Trace Element Contributions from Drained Islands in the Sacramento–San Joaquin Delta, California
San Francisco Estuary and Watershed Science 20 (2) https://doi.org/10.15447/sfews.2022v20iss2art5
CM Richardson, JK Fackrell, TEC Kraus, MB Young, A Paytan (2020). Lateral Carbon Exports From Drained Peatlands: An Understudied Carbon Pathway in the Sacramento‐San Joaquin Delta, California
Journal of Geophysical Research: Biogeosciences 125 (12), e2020JG005883 https://doi.org/10.1029/2020JG005883