Difference between revisions of "The Carmel River Watershed"
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The [[Carmel River]] connects to the Pacific Ocean through the [[Carmel River Lagoon]] in winter months when flows are high. A sandbar forms and closes the river mouth during the late spring and summer months <ref> [http://www.parks.ca.gov/?page_id=25124 California State Parks] </ref>. | The [[Carmel River]] connects to the Pacific Ocean through the [[Carmel River Lagoon]] in winter months when flows are high. A sandbar forms and closes the river mouth during the late spring and summer months <ref> [http://www.parks.ca.gov/?page_id=25124 California State Parks] </ref>. | ||
Revision as of 23:30, 9 April 2013
![](/wiki/images/thumb/7/79/CarmelRiverWatershed.jpg/400px-CarmelRiverWatershed.jpg)
Nestled between the Sierra de Salinas and Santa Lucia Mountain Ranges on the Central California Coast, the Carmel River Watershed is composed of countless small tributaries that all drain into the Carmel River, eventually forming the Carmel River Lagoon at Carmel River beach, which periodically breaches into the Pacific Ocean.[1]
Contents
Location
The Carmel River Watershed encompasses 255 square miles in Monterey County on the Central Coast of California. The watershed drains into the Carmel River which runs through Carmel Valley and the City of Carmel before reaching the Pacific Ocean. The Santa Lucia mountains create the southern border of the watershed, and the Sierra de Salinas mountains are to the north. [2].
Watershed Components
Main Stem
The Carmel River main stem is 36 miles long. With its headwaters in the Ventana Wilderness, the upper river is characterized by steep canyons and is relatively undeveloped. The lower 16 miles of river run through moderate to highly developed areas along the alluvial valley before reaching the Carmel River Lagoon [3]. River flow is monitored by the Monterey Peninsula Water Management District at four main stem gaging sites.
Dams
There are two dams on the Carmel River:
Subwatersheds
For ease of study, smaller drainages within the Carmel River Watershed have been identified. These drainages, or subwatersheds, are divided by topographic and hydraulic features [1]. Listed below are links to some of the subwatersheds with prominent issues:
- Pine Creek
- Miller Creek
- Los Padres Creek
- Rana Creek
- Mid-Carmel River
- Hitchcock Canyon
- Las Garzas Creek
- Robinson Canyon
Tributaries
The Monterey Peninsula Water Management District maintains stream gages on several of the tributaries. There are numerous tributaries feeding the Carmel River including but not limited to:
- Cachagua Creek
- Pine Creek
- San Clemente Creek
- Tularcitos Creek
- Hitchcock Creek
- Garzas Creek
- Robinson Canyon Creek
- Potrero Creek
- San Jose Creek
Lagoon
The Carmel River connects to the Pacific Ocean through the Carmel River Lagoon in winter months when flows are high. A sandbar forms and closes the river mouth during the late spring and summer months [5].
paraphrase:Artificial breaching of the sandbar (Fig. 63) reduces the frequency of flooding the lagoon wetlands, potentially leading to a shift from freshwater to saline water invertebrate species in some areas of the lagoon. Breaching also lowers the water level artificially fast, potentially leaving steelhead stranded. However, a the would put in place flood and erosion controls that would allow the lagoon to breach naturally without damaging property.[1]
Excess sediment is filling the lagoon with fine material derived from the Carmel Watershed. As the lagoon, including the southern arm, fills in with sediment, there remain fewer deep-water pools and other hiding places for juvenile fish to escape predation. Improved habitat can be achieved through the use of anchored logs or other natural materials.[1]
Physical Characteristics
Hydrology
Precipitation is transported as surface water throughout the watershed via surface water and groundwater pathways. The continuous and complex interaction of groundwater and surface water pathways is determined by several factors, including geology, season, and extraction for human consumption. Annual precipitation, which falls primarily as rain, ranges from 14 inches near the river mouth to 41 inches in the Santa Lucia Mountains.[1]
Surface Water
Surface water in the Carmel River Watershed has several potential outflow pathways that include groudwater withdrawals, transpiration due to riparian vegetation, evaporation from the water surface, and outflow into the ocean. Despite the relatively small size of individual water extraction claims compared to the entire watershed, the sum of all the water use has caused the stream to dry up during the summer months of certain years. This overuse of water supplies pose risks to fish populations.[1]
Groundwater
The Carmel River Watershed is composed of two aquifers: an unconfined alluvial aquifer and a combination of beckrock aquifers located beneath the hills around the watershed. Although the alluvial aquifer has been thoroughly assessed, the bedrock aquifers that provide water resources to large ranches and residences are not well understood. Quantifying the resources available in the in the bedrock aquifers.[1]
Geology
The physical structure of the watershed is primarily dictated by the regional geology, which is composed of igneous, metamorphic and sedimentary rocks. The formations are broken up by several faults with a range of ages and activity. Tectonically, the Carmel Watershed is carved into the Salinian block, which was transported north as part of the Pacific plate. The underlying geology dictates the physical characteristics of the sediment, including the erodibility and landslide potential.[1]
The steep canyons in the headwaters of the Carmel watershed are indicative of recent and sharp incision of the upland streams and tributaries. The high topographic gradient that leads to this incision is due to recent uplift of the Santa Lucia and Sierra de Salinas Ranges. These steep-sided canyons result in a high sediment yield as part of the incision. Additionally, the high gradient and rates of erosion make the terrain vulnerable to slope failure and landslides.[1]
The distribution of valleys and uplands are determined by preferential erosion of less resistive geologic materials. Soils and bedrock that has been crushed in the active Tularcitos fault zone are less resistant to erosion, and therefore create the lowlands in the Carmel River Watershed while the more resistant, intact bedrock composes the uplands and ridges.[1]
Sensitive Species Habitat
Steelhead: The Carmel River supports habitat for the South Central Steelhead Trout Evoluationary Significant Unit and has and supported a run of the federally listed steelhead. Unfortunately, the steelhead population has decreased compared to previous population numbers as well as other populations residing in Northern California streams. Factors such as habitat degredation, introduction of non-native species, and water diversions are likely components that have contributed to the decline. [6]
Red-legged Frogs: The California red-legged frog is present in several areas in the Carmel River Watershed, however, the state of the population is largely unknown. The information regarding the red-legged frog in the watershed is confined to the lagoon and the main stem. [6]
Issues
Watershed issues in the Carmel Watershed are complex and diverse, involving many stakeholders representing many sometimes conflicting uses of water.
Water Supply
California American Water (CalAm) extracts water from wells along the river for use by the residents of the Monterey Peninsula, as described here: CalAm Use of Carmel River Groundwater Basin. CalAm is currently making illegal diversions from the Carmel River, according to California State Order 95-10, in order to meet the water demand of the community [7]. Water supply projects incorporating a desalination plant have been proposed by CalAm and local government agencies, as well as private parties [8]. The Monterey Peninsula Water Management District (MPWMD) has initiated Aquifer Storage and Recovery (ASR) projects to capture and store excess winter flows for use during the summer months [9].
Dam Removal
Incremental motion between the Pacific and North American tectonic plates has periodically broken the crust in the Carmel Watershed. Various studies have determined that several faults show evidence of motion in Quaternary time (< 2 million years) and some have moved much more recently. The trace of the Cachagua fault is covered by the sediment stored in San Clemente Dam and it is estimated that a severe earthquake with a magnitude of up to 7.1 could hit the basin on the Tularcitos fault system, which is not far away. Therefore, San Clemente Dam is among the least safe in California. In addition to seismic hazard, sedimentation issues also drive efforts to promote dam removal.[1]
Erosion
The chief erosive processes in the Carmel Valley are bedrock landslides, shallow soil slips, rock fall, stream incision and widening, and slope gullying. Grading for roads and buildings locally over-steepens these slopes, greatly accelerating the rate of slope failure and erosion. For this reason, nearly the entire Carmel Watershed is rated as highly susceptible to erosion. However, sediment sources that maintain fish spawning habitat are impeded by the San Clemente and Los Padres dams, reducing their capacity to 90% and 50%, respectively. Additionally, in response to sediment starvation, the river channel has cut downward into its bed several meters, leaving a generally narrower, single-thread channel, with a well-defined riparian corridor.[1]
Flooding
The greatest flood during the 48 years of the Rio Robles Stream Gauge operation was the 1995 flood with approximately 16,000 cfs. That event roughly corresponds to the 65-year flood. The next highest flood caused significant damage in 1998 with a 14,700 cfs flow. As determined by Monterey County, construction of structures, grading, or any activity that requires a permit from a government agency shall not be permitted within 200 feet of a riverbank or within the 100-year floodplain (floodway), unless a special permit is granted. Although the regulatory boundary of the Carmel 100-year flood is clearly defined by the County of Monterey (Monterey County Zoning Ordinance, 21.64.130), the true position of that river shoreline is highly imprecise. Extensive urbanization from the narrows to the mouth of the Carmel River lies within the 100-year floodplain, leaving Carmel residents and businesses at risk of significant loss.[1]
Projects
- Carmel River Lagoon Restoration Plan [10]
- Carmel River Restoration Projects carried out by MPWMD [11].
- Carmel River Parkway Plan for river restoration, education, and trails [12].
- ...
Stakeholders
- Monterey Peninsula Water Management District (MPWMD)
- California-America Water Company (Cal-Am)
- Monterey County Water Resources Agency
- Carmel River Steelhead Association (CRSA)
- ...
Timeline
Listed below is a brief timeline of water rights and dam operation in the Carmel River Watershed. A more exhaustive timeline is availabe at Carmel River History.
- 1883 First known dam on the river created ½ mile below site of the current San Clemente Dam.
- 1905 To increase capacity, Pacific Imp. drills six wells near the lower end of Laureles Ranch, installs pumps
capable of drawing 2M gallons per day, and begins installing a larger pipe thru the valley and around the peninsula.
- 1919 S.F.B. Morse forms the Del Monte Properties Co. and purchases Pacific Improvement Co.’s Monterey
holdings for $1.3M.
- 1921 Carmel River becomes site of several mining operations along the lower river, including the Carmel
River lagoon
- 1930 Morse sells water system to Chester Loveland.
- 1931 Loveland raises water rates. Proponents of a public ownership estimate the cost at $1.8-$2M to
purchase water rights. First debate over public, or private water, management.
- 1935 Public ownership of water supply defeated 2 to 1.
- 1939 CW&T provides water to 7,430 Peninsula customers, irrigates 5 golf courses and services a growing
sardine cannery industry.
- 1947 San Clemente Dam is 25% silted. A filter plant opens near San Clemente Dam, improving water
quality. CW&T releases plans for the Los Padres dam, along with other improvements. Total cost $1.4M. Application for 19,000 af per year storage capacity was objected by steelhead fishermen and farmers. SWRCB grants 6,000 af per year and limits season of diversion to 10/1-5/31.
- 1953 Flood event. Rainfall at Los Padres dam was 2.11 inches in 24 hours and Carmel Valley received 1.48
inches. Carmel Valley residents compare the 1958 flood to the 1995 and 1998 floods.
- 1959 Monterey Peninsula Water Mgmt. District initiates efforts to buy out CW&T.
- 1965 In the September election, the measure was defeated 10,766 to 3,053. Loveland sells CW&T to
American Water Works Company.
- 1966 American Water Works Company creates California-American Water Co. to manage the operations of
CW&T systems.
- 1970 Cal-Am announces Peninsula water shortage. Current use is at 15,000 af per year. Cal-Am proposes a
dam in two stages.
- 1971 Cachagua dam project abandoned. A new San Clemente dam is proposed that would create a 40,000
af reservoir and yield 21,000 af per year. Army Corp. of Engineers recommends a flood control component versus the original dam.
- 1977 Monterey Peninsula Water Management District is created to augment, protect and manage water
resources
- 1995 Vote to fund construction and operation of the new Los Padres dam project is rejected 57% to 43%.
- 1996 ESA listing (threatened) on the red legged frog (Rana aurora draytinii).
- 1997 ESA listing (threatened) on steelhead trout (Oncorhynchus mykiss).
CSUMB Courses Relevant to the Carmel Watershed
References
- ↑ 1.00 1.01 1.02 1.03 1.04 1.05 1.06 1.07 1.08 1.09 1.10 1.11 1.12 Physical and Hydrologic Assessment of the Carmel River Watershed California
- ↑ MPWMD. T. Christensen and E. Geisler. 2009 Riparian Corridor Monitoring Report.
- ↑ Carmel River Watershed:Water Supply Perspective
- ↑ Carmel River Basin Principal Streamflow Gaging Stations
- ↑ California State Parks
- ↑ 6.0 6.1 MPWMD Environmental and Biological Assessment of Portions of the Carmel River Watershed Monterey County, California
- ↑ CA State Order 95-10
- ↑ Monterey County Herald
- ↑ MPWMD Water Supply Projects
- ↑ Carmel River Lagoon Restoration Plan
- ↑ MPWMD Restoration Projects
- ↑ Big Sur Land Trust - Carmel River Parkway Plan
Links
- Maps of the Carmel River Watershed
- California Central Coast Gage Locations
- Carmel River Lagoon
- San Clemente Dam
- Reservoirs
- Los Padres Reservoir
- San Clemente Reservoir
- Publications
- CSUMB-CCoWS Carmel Watershed Assessment
- EcoViz:SEP_Focus_Sites
Disclaimer
This page may contain student work completed as part of assigned coursework. It may not be accurate. It does not necessary reflect the opinion or policy of CSUMB, its staff, or students.