Putah Creek hydrology affecting riparian cottonwood and willow tree survival

  • Mark E. GrismerEmail author


Creating or recruiting new riparian forests to improve Lower Putah Creek (LPC) ecosystem functions is challenging under the modified stream flow regime developed after historic gravel mining and installation of Monticello Dam upstream. Hydrologic connectivity between riparian trees, shallow groundwater, and the low flow channel is essential towards maintaining these forests and related habitats through the annual summer and multi-year drought periods typical in this Sacramento Valley region of California. Despite increased average summer flows, significant mature cottonwood and willow tree mortality along the LPC riparian areas below the Putah Creek diversion dam in 2014 raised concerns over the soil and hydrologic factors affecting riparian vegetation survival. A forensic analysis was conducted combining annual canopy coverage fractions and tree ring studies with daily soil-water balances, low flow records, and available groundwater level Information from the past few decades to determine the key hydrologic factors affecting riparian tree survival along the LPC. The 2011–2016 drought was linked with greater than prior average soil-water deficits in 2012–2015 and lower initial soil-water storage on March 1 of 2012 and 2014 that would be expected to stress the trees. However, such stress was not apparent in decreased tree ring spacing during this period from mature (40–50 years old), deceased, and living trees. Tree canopy coverage declined dramatically (by as much as 50% as compared to the previous decade average) only in the summer of the 2014 despite a ~ 35% increase in average summer flows from 2011 to 2014. However, the regional water table aquifer levels declined at an average rate of ~ 35 mm/day in 2014 (as compared to ~ 17 mm/day in previous decade) and by several meters overall between 2011 and 2016 suggesting that deceased trees lacked access to the water table aquifer or lateral stream seepage. The increased rates of water table decline and overall depth may be associated with a large increase in adjacent irrigated almond orchard areas in 2014–2016. Knowledge of the dynamic hydrologic factors controlling sustainability of riparian trees should better inform and guide future tree restoration efforts along the LPC.


Soil-water balance Hydrology Restoration ecology Groundwater Riparian trees 



The Solano County Water Agency (SCWA) with personal aid from the Lower Putah Creek Council and the Putah Creek Streamkeeper supported this research while various landowners along the Creek also provided insights and access to their property for measurements and observations.


  1. Amlin, N. M., & Rood, S. B. (2002). Comparative tolerances of riparian willows and cottonwoods to water-table decline. Wetlands, 22(2), 338–346.CrossRefGoogle Scholar
  2. Barbour, M.G. & Whitworth, V. (2001). Natural vegetation of the Putah-Cache.
  3. Brayshaw, T. C. (1996). Catkin-bearing plants of British Columbia. Victoria: Royal British Columbia Museum.Google Scholar
  4. Busch, D. E., Ingraham, N. L., & Smith, S. D. (1992). Water uptake in woody riparian phreatophytes of the southwestern United States, a stable isotope study. Ecological Applications, 2(4), 450–459.CrossRefGoogle Scholar
  5. Cooper, D. J., D'amico, D. R., & Scott, M. L. (2003). Physiological and morphological response patterns of Populus deltoides to alluvial groundwater pumping. Environmental Management, 31(2), 0215–0226.CrossRefGoogle Scholar
  6. Dawson, T. E., & Ehleringer, J. R. (1991). Streamside trees that do not use stream water. Nature, 350(6316), 335–337.CrossRefGoogle Scholar
  7. Gordon, N. D., McMahon, T. A., & Finlayson, B. L. (1992). Stream hydrology, an introduction for ecologists. Toronto: John Wiley and Sons Inc..Google Scholar
  8. Grismer, M. E., & Asato, C. (2012). Oak savanna versus vineyard soil-water use in Sonoma County, CA. California Agriculture, 66(4), 144–152.CrossRefGoogle Scholar
  9. Horton, J. L., & Clark, J. L. (2000). Water table decline alters growth and survival of Salix gooddingii and Tamarix chinensis seedlings. Forest Ecology and Management, 140, 243–251.Google Scholar
  10. Horton, J. L., & Clark, J. L. (2001). Water table decline alters growth and survival of Salix gooddingii and Tamarix chinensis seedlings. Forest Ecology and Management, 140, 239–247.CrossRefGoogle Scholar
  11. Horton, J. L., Kolb, T. E., & Hart, S. C. (2001). Responses of riparian trees to interannual variation in groundwater depths in a semi-arid river basin. Plant, Cell & Environment, 24, 293–304.CrossRefGoogle Scholar
  12. Hortscience. (1997). Putah creek riparian vegetation summary. Prepared for the SCWA.Google Scholar
  13. Irmak, S., Kabenge, I., Rudnick, D., Knezevic, S., Woodward, D., & Moravek, M. (2013). Evapotranspiration crop coefficients for mixed riparian plant community and transpiration crop coefficients for common reed, cottonwood and peach-leaf willow in the Platte River Basin, Nebraska-USA. Journal of Hydrology, 481, 177–190.CrossRefGoogle Scholar
  14. Johnson, W. C. (1994). Woodland expansion in the Platte River, Nebraska, patterns and causes. Ecological Monographs, 64, 45–84.CrossRefGoogle Scholar
  15. Johnson, W. C., Burgess, R. L., & Keammerer, W. R. (1976). Forest overstory vegetation and environment on the Missouri River floodplain in North Dakota. Ecological Monographs, 46, 59–84.CrossRefGoogle Scholar
  16. Katz, G. (2017). How riparian hydrology affects riparian trees on the rivers of the Great Plains. Colorado Water, p. 3–6.Google Scholar
  17. Kolb, T. E., Hart, S. C., & Amundson, R. (1997). Boxelder water sources and physiology at perennial and ephemeral stream sites in Arizona. Tree Physiology, 17, 151–160.CrossRefGoogle Scholar
  18. Kranjcec, J., Mahoney, J. M., & Rood, S. B. (1998). The responses of three riparian cottonwood species to water table decline. Forest Ecology and Management, 110, 77–87.CrossRefGoogle Scholar
  19. Krasny, M. E., Vogt, K. A., & Zasada, J. C. (1988). Establishment of four Salicaceae species on river bars in interior Alaska. Holarctic Ecology, 11, 210–219.Google Scholar
  20. Larsen, S., & Alp, M. (2014). Ecological thresholds and riparian wetlands, an overview for environmental managers. Limnology, 16, 1–9. Scholar
  21. Mahoney, J. M., & Rood, S. B. (1991). A device for studying the influence of declining water table on poplar growth and survival. Tree Physiology, 8, 305–314.CrossRefGoogle Scholar
  22. Mahoney, J. M., & Rood, S. B. (1992). Response of a hybrid poplar to water table decline in different substrates. Forest Ecology and Management, 54, 141–156.CrossRefGoogle Scholar
  23. Mahoney, J. M., & Rood, S. B. (1998). Streamflow requirements for cottonwood seedling recruitment—an integrative model. Wetlands, 18, 634–645.CrossRefGoogle Scholar
  24. Millers, L., Lachance, D., Burkman, W.G. & Allen, D.C. (1991). North American maple project cooperative field manual. USDA Forest Service General Technical Report NE-154.Google Scholar
  25. Nagler, P.L., Shafroth P.B., LaBaugh, J.W., Snyder, K.A., Scott, R.L., Merritt, D.M. and Osterberg, J. (2010). The potential for water savings through the control of salt cedar and Russian olive. In Shafroth, P.B., Brown, C.A., Merritt, D.M., (Eds.), Salt cedar and Russian olive control and demonstration act science assessment. U.S. Geological Survey Scientific Investigations Report 2009-5247. 143 pages.Google Scholar
  26. Norton, A.G. Katz, A., Eldeiry, R., Waskom, R. & Holtzer, T. (2016). SB14-195 Report to the Colorado Legislature South Platte phreatophyte study. Colorado Water Institute Special Report No. 30. December.
  27. Poff, N. L., Allen, J. D., Bain, M. B., Karr, J. R., Prestegaard, K. L., Richter, B. D., Sparks, R. E., & Stromberg, J. C. (1997). The natural flow regime. BioScience, 47, 769–784.CrossRefGoogle Scholar
  28. Rood, S. B., & Heinze-Milne, S. (1989). Abrupt downstream forest decline following river damming in southern Alberta, Canada. Canadian Journal of Botany, 67, 1744–1749.CrossRefGoogle Scholar
  29. Rood, S. B., & Mahoney, J. M. (1990). The collapse of riparian poplar forests downstream from dams on the western prairies, probable causes and prospects for mitigation. Environmental Management, 14, 451–464.CrossRefGoogle Scholar
  30. Rood, S. B., & Mahoney, J. M. (2000). Revised instream flow regulation enables cottonwood recruitment along the St. Mary River, Alberta, Canada. Rivers, 7, 109–125.Google Scholar
  31. Rood, S. B., Kalischuk, A. R., & Mahoney, J. M. (1998). Initial cottonwood seedling recruitment following flood of the century on the Oldman River, Alberta Canada. Wetlands, 18, 557–570.CrossRefGoogle Scholar
  32. Sanford, R.A. (2005). Conceptual framework of the lower Putah Creek riparian water availability forecasting model. Report prepared for the SCWA.Google Scholar
  33. Sanford, R.A. (2009). Update 2009, Lower Putah Creek Riparian water availability forecasting model. Report prepared for the SCWA.Google Scholar
  34. Sanford, R.A. (2011). Lake Solano seepage loss investigations 1958-2009. Report prepared for the SCWA.Google Scholar
  35. Schmidt, J. C., Webb, R. H., Valdez, R. A., Marzolf, G. R., & Stevens, L. F. (1998). Science and values in river restoration in the Grand Canyon. Bioscience, 48, 735–747.CrossRefGoogle Scholar
  36. Segelquist, C. A., Scott, M. L., & Auble, G. T. (1993). Establishment of Populus deltoides under simulated alluvial groundwater declines. American Midland Naturalist, 130, 274–285.CrossRefGoogle Scholar
  37. Shafroth, P. B., Auble, G. T., Stromberg, J. C., & Patten, D. T. (1998). Establishment of woody riparian vegetation in relation to annual patterns of streamflow, Bill Williams River, Arizona. Wetlands, 18, 577–590.CrossRefGoogle Scholar
  38. Shafroth, P. B., Stromberg, J. C., & Patten, D. T. (2000). Woody riparian vegetation response to different alluvial water table regimes. Western North American Naturalist, 60(1), 6.Google Scholar
  39. Shafroth, P. B., Stromberg, J. C., & Patten, D. T. (2002). Riparian vegetation response to altered disturbance and stress regimes. Ecological Applications, 12, 107–123.CrossRefGoogle Scholar
  40. Snyder, K. A., & Williams, D. G. (2000). Water sources used by riparian trees varies among stream types on the San Pedro River, Arizona. Agricultural and Forest Meteorology, 105, 227–240.CrossRefGoogle Scholar
  41. Sparks, R. E. (1995). Need for ecosystem management of large rivers and their floodplains. Bioscience, 45, 168–182.CrossRefGoogle Scholar
  42. Stanford, J. A., Ward, J. V., Liss, W. J., Frissell, C. A., Williams, R. N., Lichatowich, L. A., & Coutant, C. C. (1996). A general protocol for restoration of regulated rivers. Regulated Rivers: Research & Management, 12, 391–431.CrossRefGoogle Scholar
  43. Stromberg, J. C. (1993). Fremont cottonwood-Goodding willow riparian forests, a review of their ecology, threats, and recovery potential. Journal of the Arizona–Nevada Academy of Science, 26, 97–111.Google Scholar
  44. Stromberg, J. C., & Patten, D. T. (1990). Riparian vegetation instream flow requirements, a case study from a diverted stream in the eastern Sierra Nevada, California. Environmental Management, 14, 185–194.CrossRefGoogle Scholar
  45. Stromberg, J. C., Patten, D. T., & Richter, B. (1991). Flood flows and Sonoran riparian forests. Rivers, 2, 221–235.Google Scholar
  46. Stromberg, J. C., Tiller, R., & Richter, B. (1996). Effects of groundwater decline on riparian vegetation of semiarid regions, the San Pedro, Arizona. Ecological Applications, 64, 113–131.CrossRefGoogle Scholar
  47. Taylor, J. P., Wester, D. B., & Smith, L. M. (1999). Soil disturbance, flood management, and riparian establishment in the Rio Grande floodplain. Wetlands, 19, 372–382.CrossRefGoogle Scholar
  48. Thomasson, H.G., Olmsted, F.H. & LeRoux, E.F. (1960). Geology, water resources and usable ground-water storage capacity of part of Solano County, California. USGS Water Supply Paper No. 1464.Google Scholar
  49. Turner, R.M. (1974). Quantitative and historical evidence of vegetation changes along the upper Gila River, Arizona. USGS Professional Paper 655-H.Google Scholar
  50. Ware, G. H., & Penfound, W. T. (1949). The vegetation of the lower levels of the floodplain of the South Canadian River in central Oklahoma. Ecology, 30, 478–484.CrossRefGoogle Scholar

Copyright information

© Springer Nature Switzerland AG 2018

Authors and Affiliations

  1. 1.Hydrologic SciencesUC DavisDavisUSA

Personalised recommendations