CalAm Use of Carmel River Groundwater Basin

A watershed-related issue examined by the ENVS 560/L Watershed Systems class at CSUMB.

Summary

The Carmel Watershed is the primary source of fresh water for residents of the Monterey Peninsula that relies entirely on annual rainfall as its only water resource. Currently the California American Water Company (Cal-Am) utilizes wells along the Carmel River watershed to tap the Carmel Aquifer and withdraw 14,000 acre feet of water annually. However in order to meet the mandate of Order WR 95-10 (see below) Cal-Am must find an alternate source for 10,730 acre feet of water annually. The issue is that despite increased conservation efforts, demand for water far exceeds supply and viable alternatives are still in the planning stages and have not been constructed. Thus Cal-Am has continued its illegal diversions from the Carmel River in order to meet the water demands of the Monterey Peninsula.

Location

• The Carmel Watershed is 255 square miles and is located in Monterey County, CA. The region is bounded by the Santa Lucia mountain range to the southwest and the Sierra de Salinas mountains to the Northeast.

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Resource/s at stake

Water

The resource of concern in this watershed-related issue is the water captured by the Carmel Watershed. The surface water supplies were originally thought to be a separate resource from the groundwater, however in 1995 the SWRCB ruled that the groundwater wells were subject to SWRCB jurisdiction . California's Groundwater Bulletin 118 estimated the groundwater storage capacity of the Carmel Valley basin to be between 36,000 and 60,000 acre-feet .

The Seaside groundwater basin is the only other water source CalAm is using to supply the Monterey Peninsula. It has been determined that this basin has a safe yield of 3,000 AF/year, but is being drafted at a rate of 5,600 AF/year. It is agreed that the Seaside Basin is being overdrafted.

A recent adjudication decision in 2008 limited the amount of water to be taken out of the Carmel River to 11,285 AF/year and out of the Seaside Basin to 3,504 AF/year.

Steelhead Trout and Red-legged Frogs

Many are concerned about overdrafting the Carmel River because it is home to a Steelhead population and Red-legged frogs. Steelhead and Red-legged frogs in the South-Central California region are a federally threatened species , and are protected under the federalEndangered Species Act. A decrease in surface water in the Carmel River may lead to a decrease in Steelhead habitat, and a reduction in the Steelhead population.

Kevan Urquhart, a Senior Fisheries Biologist for the Monterey Peninsula Water Management District, testified before the State Water Resources Control Board to determine if there should be a Cease & Desist Order against CalAm because of their diversions from the Carmel River under Order 95-10. Urquhart testified:

• The Steelhead population has not recovered, but has improved since the SWRCB Order 95-10.

• The first two CalAm diversion cuts will not significantly improve Steelhead or Red-legged frog habitat. The elimination of CalAm’s illegal diversions is necessary for a complete Steelhead recovery. The elimination of diversions is not an emergency measure because the proposed first two cuts in diversions will not affect the wetness of the river year round.

• Cutbacks in diversions during the summer/fall low flow season would be most beneficial

• If the 4 proposed cutbacks were implemented, there might be flows to the lagoon for a month to a month and a half longer during critically dry years. In normal years, flows may be prolonged two and half weeks to a month later. During wetter years, there may be flows to the lagoon a month to a month and two thirds longer.

• Dredging the Los Padres Reservoir and expanding the Aquifer Storage and Recovery in the Seaside basin would be more effective mitigation strategies to recover the aquatic habitat.

Agriculture and Tourism

There are many vineyards that depend on water from the Carmel Watershed. Georis, Parsonage, Bernardus, Boete, Chateau Julien, Chataeu Sinnet, Cima Collina, Figge Cellars (Pelio Vineyard), Galante, Hellar Estate, Joullian and Talbott Vineyards are some of the winemakers growing grapes in the Carmel watershed .

Several golf courses are maintained within and nearby the Carmel watershed. The golf industry brings many tourists to the Monterey area .

Inherent Value

The Carmel River is also a valued part of the community and is a social resource. The river's aesthetic and source of community leisure and relaxation is a resource that cannot be easily quantified. "The Carmel is a lovely little river. It isn't very long but in its course it has everything a river should have" John Steinbeck, Cannery Row, 1945

Stakeholders

• Federal Agencies
  • U.S. Army Corps of Engineers
  • U.S. Fish and Wildlife Service
  • NOAA Fisheries
• State Agencies
  • California Coastal Commission
  • California Department of Fish and Game
• Local Agencies
  • Monterey County Public Works Department
  • Monterey County Water Resources Agency
  • Monterey Peninsula Water Management District
  • Central Coast Regional Water Quality Control Board
• Private Interests
  • California American Water
  • Steelhead and those concerned with their well being
    • For example the Pacific Rivers Council
  • Private well owners

Laws, policies, & regulations

Under the California permit system, once a permittee has completed construction of a diversion structure and applied the water to beneficial use, the State Water Resources Control Board (SWRCB) investigates to confirm completion and compliance. The SWRCB will issue a license confirming the amount of water found to have been perfected by reasonable beneficial use subject to the terms and conditions included in the permit and required by statute and California case law.

Between 1987 and 1991 the SWRBC received formal complaints from four stakeholder organizations within the Carmel Valley: the Carmel River Steelhead Association, the Sierra Club, the Residents Water Committee, and the California Department of Parks and Recreation. Complaints alleged that pumping of the Carmel River Aquifer by Cal-Am:

• Caused observable recession of the Carmel River riparian zone
• Was Destroying habitat for the then threatened post 1998 endangered Steelhead Salmon
• Violated the public trust doctrine – stating that the harvesting of a public resource (Carmel River water) must not interfere with the ability of the public to utilize that resource .

In 1995 the SWRCB upheld the allegations of the Carmel River stakeholder groups, determining that Cal-Am had no legal right to 10,730 acre-feet of the 14,000 drafted annually and passed Order WR 95-10 . This Cease and Desist order included a mitigation plan requiring that Cal-Am reduce the amount pumped from the Carmel River via a series of options.

These options included:

• Appropriating/purchasing legal rights to the water in overdraft
• Greater reliance on the nearby Seaside Aquifer
• Building of a new dam and/or exploration of alternative and renewable sources of fresh water such as desalination and waste water treatment.

Since Cal-Am actions were found to be "taking" of a threatened species (Steelhead Salmon) Order WR95-10 exposed Cal-Am to prosecution by the federal government under the Endangered Species Act . This additional legal action resulted in a settlement agreement between Cal-Am and the National Marine Fisheries where Cal-Am agreed to implement a number of measures that "reduce the impact of its [Cal-Am] operations in the Carmel River on steelhead and their habitat" .

Systems

• Seventy five percent of the Monterey Peninsula's water supply is pumped from the Carmel River alluvial aquifer . If there is not equivalent recharge to replenish the pumped water, the water table will decrease. Irrigation along the channel of the Carmel river currently mitigates vegetation mortality and bank erosion caused by a depressed water table .
• Two endangered species, red-legged frogs (Rana aurora) and steelhead trout (Oncorhynchus mykiss), depend on the Carmel River for habitat.
• The Carmel River needs a sufficient supply of water to maintain healthy riparian and river ecosystems.

Science

• Physical and Hydrologic Assessment of the Carmel River Watershed California
• Carmel Valley Groundwater Basin
• Watershed Assessment and Action Plan of the Carmel River Watershed California

Tools

Studying groundwater is difficult at best. However, hydrogeologists can use various clues in the local environment to model and measure groundwater in efforts to try and preserve the balance of water replenishment and removal. The Monterey Peninsula Water Management District (MPWMD) is responsible for the monitoring of water production on the Carmel river watershed and consistently works to reduce the negative impacts of anthropogenic effects. As a result the monitoring of the physical properties of the river and its aquifer are crucial to the MPWMD's mission and require various tools.

Currently, MPWMD possesses 27 groundwater wells throughout the Carmel watershed that are used for monthly measurements on water table height . Some of the wells have recording transducers for recording data at various intervals and could be applied for "real time" monitoring. The District also has access to 1,000 registered and metered wells (99% of the total number of wells). These resources combined can produce accurate and precise snap shots of ground water capacity and the water table. Groundwater well sites are also used to test for potential seawater intrusion via monthly experiments observing nitrate, chloride, sodium and 12 other constituents concentrations.

Groundwater monitoring is not complete without information on surface flows. As a result MPWMD possesses 2 continuously recording stream flow gages at Via Mallorca road near Carmel by the sea , and at Robles del Rio road just above Carmel Valley . Both gages are operated and maintained by the USGS.

Data combined from wells and surface flows can be used to create predictor models of hydrological flow in the watershed. Values at the wells and the surface flow gages can be used to calibrate models. Models can then be used in all sorts of ways; primarily though tthe "what if scenarios." A good example of this is a report written by Watson and Casagrande (2004) on the Potential Effects of Groundwater Extractions on Carmel Lagoon . The report uses the modeling software: Tasier . Other software packages used in modeling watersheds include the US Army Corps of Engineers HEC packages . HEC-HMS is widely used in modeling watershed activity.

Future research

Future research in the Carmel watershed could be focused on capacity issues of the Carmel aquifer. More information is needed on the quantity of water that could be extracted without the risk of land subsidence and losses in aquifer storage capacity . Another issue is salt water intrusion. While a granite sill currently protects the Carmel aquifer from significant salt water intrusion (unlike in the Salinas Valley ), questions remain as to the minimum depth of the aquifer before salt water intrusion becomes a reality . Both these issues require attention to avoid irreversible problems that will limit available fresh water supplies on the Peninsula.

Master's candidates in the Coastal and Watershed and Environmental Policy program at California State University of Monterey Bay could pursue either of the above mentioned future research. Both will require significant modeling of the groundwater aquifer combined with visualizations for policy purposes. With unlimited funding, one could set up real time measuring wells throughout the carmel watershed to develop a 3D model of the entire aquifer. At this point real conclusion could be made about minima levels of the aquifer required to avoid land subsidence and salt water intrusion.

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.