Friday, August 31, 2012

Pumping and Diversion TMDL

One of the major issues currently facing the Ventura River is 'pumping and diversion'.  The river has been listed by the State Water Resources Control Board as 'impaired' in Reaches 3 and 4 due to excessive water diversion.  The water board is now considering developing a TMDL, or 'Total Maximum Daily Load', for this impairment.  The alternative is a MOA (Memorandum of Agreement) and plan of action for local water agencies to cooperate on a groundwater management plan.

Diversion of surface flows occurs at the Robles Diversion Dam (Reach 4) and at Foster Park (Reach 3) as well as smaller private diversions.  Pumping occurs at numerous wells that extract water from the shallow aquifers that are connected to surface flows.  In both cases, the amount of water flowing in the river is diminished, impairing ecological function.  For example, low flows become a problem when combined with excessive algae growth - this reduces dissolved oxygen levels that aquatic life depends upon.  (See Algae: problem or symptom?)

Pumping water from wells during dry summer months may cause pools to rapidly dry up, stranding and killing native steelhead trout and other aquatic species.  Although this often goes unseen (they become fodder for predators such as herons, racoons, etc.), fisheries managers in past years have responded by relocated fish from drying pools.

Pumping and Diversion has been discussed during several of the recent watershed council meetings, along with presentations about water rights and the effects of wells on surface flows.  As one would expect, there is controversy surrounding the cause and effect, and some even question if there is reason for the impairment listing.

In order to illustrate the problem, Santa Barbara ChannelKeeper produced this video:

The timelapse sequence in this video and the pressure logger illustrate the rapid filling and drying of a pool on the Ventura River Preserve.  Because this occurs independently of time of day it suggests that something other than natural evapotranspiration is occurring to impact surface flows in the river.

To illustrate the issue, local groundwater professional Jordan Kear has provided presentations to the Watershed Council. These graphics are from Surface & Groundwater Interaction Study, Kear 7-17-12

The main stem of the Ventura River is divided into two groundwater basins, with the division occurring at Foster Park.

To understand what happens to surface flow, one must understand how the stream interacts with groundwater.  A stream may be 'gaining' or 'losing' depending upon the level of the water table beneath and adjacent to the river channel.  And when the water table drops far enough the stream becomes 'disconnected.' 

One of the areas in question is Reach 4, the section of river downstream of the Robles Diversion  within the upper Ventura River groundwater basin.  As the figure below illustrates, this 'Robles Reach' is usually a 'losing stream,' which often becomes 'disconnected' in dry periods. 

Then, as river flows increase during winter months and the groundwater basin fills back up, and surface flows re-establish.  (In extremely wet periods it may also become a 'gaining stream')

Surface water (dotted line) and Groundwater (solid blue line) interaction
 in the Robles Reach of the Ventura River  (Kear Groundwater)

Although this Surface & Groundwater Interaction Study concluded that "pumping of wells has a relatively minor effect on river flow," this was based upon an experiment that revealed the Meiners Oaks Water District wells reduced river flows by up to 1.5 cfs (cubic feet per second.)  However, this conclusion does not take into account the cumulative effects of multiple wells pumping from the same groundwater basin when summer inflows from Matilija Creek may only be 5-10 cfs or less.

 Reach 4 - Wells within 1000 ft of Ventura River

What this study does demonstrate is that there is some direct interaction between groundwater pumping and surface flows.  What is less clear is the effect from wells farther from the river, but within the larger Upper Ventura River groundwater basin.

Wells within the Upper and Lower Ventura groundwater basins

Last year, a first cut at developing a water budget for the two groundwater basins was presented with the Upper and Lower Ventura River Basin Groundwater Budget.  (The first draft of this analysis suggested an overdraft of 3,240 acre-feet per year, before Lake Casitas storage/supply was added.)

Reach 3 is under similar stress, as the City of Ventura has recently constructed new wells at Foster Park.  Although these wells are regulated by NOAA Fisheries, who have established minimum flow criteria, this reach is influenced by other extractions which have cumulative effects on surface flows.

Although this is clearly a difficult issue, the TMDL listing has brought many of the major water suppliers and users together to potentially work cooperatively on a groundwater management plan.

It is important to understand that this is not only about endangered species and recreation, which are protected under the Clean Water Act, but most importantly the future sustainability of our communities, including over 100,000 residents in Ojai and Ventura:
  • Our communities depend almost entirely on the Ventura River for water supply
  • In recent years, expansion of agriculture as well as planned urban development are increasing pressure on this limited resource
  • New wells are being constructed, increasing groundwater pumping
  • Currently there is no coordinated oversight of groundwater resources on the main stem of the Ventura River
  • We are clearly at, or above, the maximum sustainable water extraction from the Ventura River

More info:

Pumping and Diversion Fact Sheet

A Really Short Course on Water Rights, Birosik 6-13-12

Surface & Groundwater Interaction Study, Kear 7-17-12 (2.8 Mb)

Upper and Lower VRB GW Budget and Management Presentation 05-25-2010 (3.4 Mb)

Upper and Lower Ventura River Basin Groundwater Budget and Management Plan (18 Mb)

See also:


Monday, August 20, 2012

Arundell Barranca - flood control or green infrastructure?

Ventura County Watershed Protection (formerly Flood Control) District is undergoing studies to address potential flooding impacts in the lower Arundell Barranca watershed.  According to hydraulic models, flood risk is higher than past FEMA models, with potential estimated 100-year flood damages of $62,170,700.  The District initially hoped to enlarge the concrete channel to accommodate the 100 year flows, and repair deterioration of Arundell Barranca Channel.

The diagram above shows the affected area - Arundell Barranca drains a large urban and agricultural area and discharges into the Ventura Harbor.

The diagram above illustrates the extent that the urban area has been channelized - compare this infrastructure with the historic condition in the 1945 aerial below.

The photo below shows the current state of the concrete in Arundell Barranca.  This channel conveys a constant flow of no less than 0.67 - 2 cfs in dry weather into the Ventura Harbor.  This amounts to up to 1400 acre feet per year of wasted water. If reused in some manner within the City of Ventura, this stormdrain discharge is sufficient volume to offset the proposed extraction at Saticoy Well #3.

During peak storm events, the channel conveys extremely high flows and tons of sediment into the harbor.  This sediment is periodically dredged and placed on nearby beaches.  Because of the direct hydrologic connection between urban, industrial, and agricultural runoff, these sediments and the water in the harbor contain high levels of toxins ranging from bacteria and metals to agricultural chemicals.

According to Watershed Protection District, the CEQA process has included:
  • Initial Study/Notice of Preparation Review : 1/20 – 2/18/2011
  • Scoping Meeting: 01/27/2011
  • Ventura Port District Board Meeting: 03/30/2011
  • Initial Study on line at:
  • EIR On Hold due to Public Comments Received
  • District Contracted with NHC for a Study to Quantify Baseline Condition and Further Investigate Existing Conditions and Potential Alternatives ($310,000 Contract)

Comments received included:
  • Increased Capacity = Increased Sediment & Harbor Dredging Costs
  • Increased Capacity = Increased Pollutants (Trash, Debris, Bacteria, Nitrates, Pesticides, etc.)
  • Project Should Provide Multiple Benefits
  • Coordinate with City of Ventura on Potential Treatment Wetlands Upstream of the SCR Estuary – Increases Grant Funding Eligibility
  • Redirect Channel to the Santa Clara River
  • Modify Outlet to Avoid Eddy at Stub Channel Confluence
  • Redirect Outlet to Avoid Damage to Boats, Docks, and Revetment
  • Build a Detention Basin on Farmland Instead

Next Steps:
  • Public Meeting to Present NHC Alternatives Study Results: July 19, 2012
  • Consider Public Comments and Feasibility, Narrow Down the Alternatives to Carry Forward in the EIR
  • Resume Preparation of the Draft EIR, to Include Additional Opportunities for Public Review and Comment
  • Draft EIR Public Meeting
  • Final EIR Board of Supervisors Hearing


The Surfrider Foundation has provided comments to this process, expressing concern that re-constructing the existing flood control channels to accommodate the 100-year storm flows will perpetuate a water quality problem that is in dire need of mitigation. We strongly recommend that alternatives be seriously considered in order to realize the opportunity for an integrated project that will mitigate flooding and improve water quality in the lower Santa Clara River watershed and Ventura Harbor.

The 2011 Water Quality Report provides a good overview of the water quality issues of concern. It is
noted that industrial discharges from Harris Water have ceased, but there is no indication of the volume of other industrial discharges into the barranca. Such discharges often have a negative short-term effect that is not captured in grab samples. For instance the recent spill reported in the news delivered hydrocarbon effluent to the harbor directly affecting summertime recreational uses (Spill near Ventura Harbor traced to barranca drain outlet -VCStar, Aug 1, 2012)

Industrial and agricultural discharges and spills also have a long term effect, as toxins accumulate in
sediments that are routinely dredged and discharged onto recreational beaches, as well as bioaccumulate in shellfish and other aquatic life which can negatively affect the productivity of the food chain and ultimately impact human health.  And repeated fish die-offs may be related to accumulated nutrient levels in the stagnant backwater channels in the harbor (most recently, Officials believe a lack of oxygen killed thousands of small fish Monday in the Ventura Harbor.
- April 18, 2011)

Therefore, although the report indicates that “a large fraction of the constituents were mostly above method reporting limits, but below regulatory objective levels,” this should not trivialize the seriousness of the discharge from Arundell Barranca.

There is a significant volume of water constantly flowing from this storm drain system, and an analysis of upstream sources should be conducted to determine opportunities for flow reduction and/or stormwater capture upstream of the project site, before flows reach Harbor Blvd. Various ‘green infrastructure’ approaches may be applicable within the urban watershed to mitigate both low and high flow volumes currently present in the concrete channel. Even modifying portions of the channel to include a soft bottom low flow channel may help reduce flows through infiltration.  We have previously presented a vision for such an 'urban retrofit' for the Sanjon Barranca in Ventura.


This is not a new problem, and in 1999 the City of Ventura was leading the charge on a creative approach to redirect flows away from the harbor and treat the water with a green infrastructure approach.

One proposal that has been circulated recently illustrates a vision for an Arundell Estuary Park, that would combine engineered treatment wetlands with public access and trails to beatify the area and solve the water quality problem in the harbor.

One thing is certain: a single purpose flood control project will perpetuate this problem for many decades to come.  Now is the time to develop a multi-purpose multi-agency solution to one of the most serious water quality problems on our coast.

More info:

Arundell Barranca Channel Improvements, Ventura County Watershed Protection District website,

Arundell Barranca Environmental Monitoring Final Report

City of San Buenaventura's May 1999 "Ventura Keys and Arundell Barranca Watershed Project Alternatives Report" (7.3MB, PDF)


Tuesday, August 7, 2012

Surfers' Point at Ventura County Fair

The 2012 VENTURA COUNTY FAIR runs from Wednesday August 1 through Sunday August 12.  The Fair provided a small booth space for an educational display describing the Surfers' Point Managed Shoreline Retreat Project.  Along with posters, we installed a small television monitor which loops our chapter videos.  Thanks to those who helped make this happen, as this display is potentially viewed by thousands of people!

More info:

Monday, August 6, 2012

West Coast EBM Network video

New video profiles several of the projects within the West Coast Ecosystem-based Management Network.