North Coastal Area Action Program: A Study of the Smith River Basin and Plain

California Department of Water Resources (DWR) | December 17th, 1970

The 770-square-mile Smith River Basin and Plain in the northwestern corner of California has adequate water supplies overall, but a problem exists in distributing the w

The 770-square-mile Smith River Basin and Plain in the northwestern corner of California has adequate water supplies overall, but a problem exists in distributing the water to the areas of use. The present water needs are now met, and can probably continue to be met, from groundwater pumping and direct diversion of unregulated streamflow. The Bertsch Tract and surrounding area near Crescent City has experienced serious groundwater problems such as low well yields, high iron content, bad taste, and sewage contamination. Existing and proposed subdivision development around Lakes Earl and Talawa could eventually pose a water quality threat to the lakes and ground water if individual septic systems are used for sewage disposal. The Smith River Basin, including Lakes Earl and Talawa, is subject to periodic flooding which does considerable damage to roads, bridges, and agricultural land. Urban encroachment onto floodplain lands would increase the damages of these floods tremendously. A large part of the study area's projected water demand will come from areas near Crescent City that could be served by the Crescent City system. The Department of Water Resources recommends that Del Norte County encourage the extension of Crescent City water service to such areas, including the Bertsch Tract. The Department further recommends that the water in Lakes Earl and Talawa be tested periodically to determine if pollution from septic systems is reaching the lakes, that a floodplain management program be developed for the Smith River, that adequate water well construction and sealing standards be adopted and enforced, and that all levels of government make a concerted effort to preserve the outstanding natural beauty and aesthetic character of the Smith River Basin.

Petaluma Valley Historical Hydrology and Ecology Study

San Francisco Estuary Institute (SFEI) | March 1st, 2018

This study examines the historical hydrology and ecology of the Petaluma River watershed prior to major Euro-American modification, and analyzes landscape changes over th

This study examines the historical hydrology and ecology of the Petaluma River watershed prior to major Euro-American modification, and analyzes landscape changes over the past two centuries. Synthesizing information from hundreds of archival documents, the research reconstructs the historical form and function of wetland, riparian, and aquatic habitats and stream channels throughout the watershed, providing insights into habitat extent and distribution, streamflow and sediment dynamics, vegetation composition, wildlife support, and landscape change. Findings from this research can be used to help set restoration targets and to prioritize multi-benefit opportunities to restore wildlife habitat, enhance flood protection, increase groundwater recharge, and improve sediment management. This Executive Summary highlights key findings from the study. 

Primary Production in the Delta: Then and Now

University of California, Davis (UC Davis) | October 3rd, 2016

To evaluate the role of restoration in the recovery of the Delta ecosystem, we need to have clear targets and performance measures that directly assess ecosystem function

To evaluate the role of restoration in the recovery of the Delta ecosystem, we need to have clear targets and performance measures that directly assess ecosystem function. Primary production is a crucial ecosystem process, which directly limits the quality and quantity of food available for secondary consumers such as invertebrates and fish. The Delta has a low rate of primary production, but it is unclear whether this was always the case. Recent analyses from the Historical Ecology Team and Delta Landscapes Project provide quantitative comparisons of the areal extent of 14 habitat types in the modern Delta versus the historical Delta (pre-1850). Here we describe an approach for using these metrics of land use change to: (1) produce the first quantitative estimates of how Delta primary production and the relative contributions from five different producer groups have been altered by large-scale drainage and conversion to agriculture; (2) convert these production estimates into a common currency so the contributions of each producer group reflect their food quality and efficiency of transfer to consumers; and (3) use simple models to discover how tidal exchange between marshes and open water influences primary production and its consumption. Application of this approach could inform Delta management in two ways. First, it would provide a quantitative estimate of how large-scale conversion to agriculture has altered the Delta's capacity to produce food for native biota. Second, it would provide restoration practitioners with a new approach—based on ecosystem function—to evaluate the success of restoration projects and gauge the trajectory of ecological recovery in the Delta region.

Primary Production in the Sacramento-San Joaquin Delta: A Science Strategy to Quantify Change and Identify Future Potential

San Francisco Estuary Institute (SFEI) | May 20th, 2019

Today’s Sacramento-San Joaquin Delta is an unusually low-productivity estuary. The constraints on primary production and the relative importance of different production

Today’s Sacramento-San Joaquin Delta is an unusually low-productivity estuary. The constraints on primary production and the relative importance of different production sources to the food web are major ecological uncertainties in the Delta system. Understanding how the extensive historical changes in the Delta landscape have altered primary production has the potential to inform restoration planning and management across the region.  The Delta Landscapes Project (SFEI-ASC 2014) has recently produced information that allows us, for the first time, to answer questions about historical primary production and carrying capacity from quantified changes in the areal extent and spatial configuration of habitat types in the Delta since the mid-19th century. Our focus is on estimating primary production because the potential capacity of ecosystems to support fish, bird and other wildlife populations is set by primary production – the supply of food required to produce animal biomass. 

Punctuated Sediment Discharge during Early Pliocene Birth of the Colorado River: Evidence from Regional Stratigraphy, Sedimentology, and Paleontology

Sedimentary Geology (Elsevier) | January 1st, 2018

The Colorado River in the southwestern U.S. provides an excellent natural laboratory for studying the origins of a continent-scale river system, because deposits th

The Colorado River in the southwestern U.S. provides an excellent natural laboratory for studying the origins of a continent-scale river system, because deposits that formed prior to and during river initiation are well exposed in the lower river valley and nearby basinal sink. This paper presents a synthesis of regional stratigraphy, sedimentology, and micropaleontology from the southern Bouse Formation and similar-age deposits in the western Salton Trough, which we use to interpret processes that controlled the birth and early evolution of the Colorado River. The southern Bouse Formation is divided into three laterally persistent members: basal carbonate, siliciclastic, and upper bioclastic members. Basal carbonate accumulated in a tide-dominated marine embayment during a rise of relative sea level between ~ 6.3 and 5.4 Ma, prior to arrival of the Colorado River. The transition to green claystone records initial rapid influx of river water and its distal clay wash load into the subtidal marine embayment at ~ 5.4–5.3 Ma. This was followed by rapid southward progradation of the Colorado River delta, establishment of the earliest through-flowing river, and deposition of river-derived turbidites in the western Salton Trough (Wind Caves paleocanyon) between ~ 5.3 and 5.1 Ma. Early delta progradation was followed by regional shut-down of river sand output between ~ 5.1 and 4.8 Ma that resulted in deposition of marine clay in the Salton Trough, retreat of the delta, and re-flooding of the lower river valley by shallow marine water that deposited the Bouse upper bioclastic member. Resumption of sediment discharge at ~ 4.8 Ma drove massive progradation of fluvial-deltaic deposits back down the river valley into the northern Gulf and Salton Trough. These results provide evidence for a discontinuous, start-stop-start history of sand output during initiation of the Colorado River that is not predicted by existing models for this system. The underlying controls on punctuated sediment discharge are assessed by comparing the depositional chronology to the record of global sea-level change. The lower Colorado River Valley and Salton Trough experienced marine transgression during a gradual fall in global sea level between ~ 6.3 and 5.5 Ma, implicating tectonic subsidence as the main driver of latest Miocene relative sea-level rise. A major fall of global sea level at 5.3 Ma outpaced subsidence and drove regional delta progradation, earliest flushing of Colorado River sand into the northern Gulf of California, and erosion of Bouse basal carbonate and siliciclastic members. The lower Colorado River valley was re-flooded by shallow marine waters during smaller changes in global sea level ~ 5.1–4.8 Ma, after the river first ran through it, which requires a mechanism to stop delivery of sand to the lower river valley. We propose that tectonically controlled subsidence along the lower Colorado River, upstream of the southern Bouse study area, temporarily trapped sediment and stopped delivery of sand to the lower river valley and northern Gulf of California for ~ 200–300 kyr. Massive progradation of the fluvial-deltaic system back down the river valley into the Salton Trough starting ~ 4.8–4.5 Ma apparently was driven by a huge increase in sediment discharge that overwhelmed the sediment-storage capacity of sub-basins along the lower river corridor and established the fully integrated river channel network.

Reconstructing the Mediaeval low stands of Mono Lake, Sierra Nevada, California, USA

Holocene (Sage Journals) | December 1st, 2019

Palaeosimulations of Mono Lake covering the past 2 kyr have been conducted using a water balance model forced with tree-ring derived inflow estimates. The results show tw

Palaeosimulations of Mono Lake covering the past 2 kyr have been conducted using a water balance model forced with tree-ring derived inflow estimates. The results show two low stands, during the ninth to tenth and twelfth to thirteenth centuries, that agree well in timing and magnitude with those described by Stine (1987, 1990, 1994) on the basis of geomorphic evidence and relict trees and shrubs exposed on Mono Lake's artificially exposed shorelands. The lake simulation provides independent corroboration of the timing and magnitude of Stine's drought-induced low stands and supports the accuracy of tree-ring-derived estimates of Mediaeval precipitation and runoff reductions in the central Sierra Nevada. Specifically, we estimate that during the two Mediaeval droughts, centennial average precipitation and river runoff in the central Sierra Nevada reached as low as 75% of the twentieth century values, with multidecade averages as low as 60—65%. In both magnitude and duration, these droughts far exceed anything experienced in the region during modern times. An analysis of the spatial patterns of reconstructed drought indices shows that the particular `two drought' Mono Lake low stand signal was focused over central and southern California, indicating the dominant role of boreal winter precipitation deficits. In this respect, the `Great Sierra Nevada droughts' were somewhat distinct from the more general Great Basin/far western Plains pattern of Mediaeval aridity over the western USA.

Report of the Board of Commissioners on the Irrigation of the San Joaquin, Tulare, and Sacramento Valleys of the State of California

U.S. Geological Survey (USGS) | July 15th, 1874

Report of the Commissioners of Fisheries for the State of California for the Years 1883-4

State of California | January 31st, 1885

Report of the Commissioners of Fisheries of the State of California for the Year 1880

State of California | January 31st, 1881

Report of the Commissioners of Fisheries of the State of California for the Years 1870 and 1871

State of California | January 31st, 1872