Current Alternatives and Costs
- Overview
- Alternatives 2A/T4 Described
- Alternatives 9D/T3 Described
- Alternatives Benefit to Cost Summary Comparison
- Local Sponsor Concerns
- Locally Requested Plans
- What's Next?
Overview
Since 1999, first Congressman Sam Farr and then Action Pajaro Valley have sponsored a continuous community stakeholder input process to provide community input to the United States Army Corps of Engineers (USACE) regarding a flood protection plan with the potential for community acceptance.
In March 2004, the Boards of Supervisors of Santa Cruz and Monterey Counties preliminarily endorsed Pajaro River Project Alternative 2A with bench excavation and Tributary Alternative T4 for purposes of further analysis and for exploring final design. The Boards included direction to explore reducing the levee setback distances to decrease the amount of private land impacted, and also requested that the USACE explore a "ring levee" around the developed areas of Watsonville and Pajaro, leaving other areas with a lower level of protection.(for more information on all of the alternatives, please go to the 19 alternatives considered page.)
While alternatives 2A with bench excavation and T4 are still under consideration by the USACE and will be fully analyzed in the the General Reevaluation Report (GRR) and EIS/EIR, the USACE early evaluation of these alternatives indicates that they cannot be the Recommended USACE (NED) Project because they are too expensive and do not have a high enough Benefit-to-Cost ratio for Federal Participation.
Instead, the USACE is preliminarily recommending Pajaro River Project Alternative 9D (expanded ring levee) for the Pajaro River mainstem and Tributary Alternative T3 for Corralitos/Salsipuedes Creeks as the recommended Federal NED Plan. These project alternatives are described below in detail. The alternatives were designed to reduce project costs and provide increased flood protection to urban areas in alignment with federal policy to maximize the economic benefit of federal investments.
The 9D alternative provides a 100 year level of protection for the City of Watsonville and the Town of Pajaro while maintaining the existing level of protection for farmland below Highway 1 and above Salsipuedes Creek.
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Because neither Santa Cruz nor Monterey counties support Pajaro River Project Alternative 9D (although they do support T3 as discussed below), there are additional Locally Requested Plans being analyzed that are cheaper than Alternative 2A but provide limited flood protection in the agricultural areas that alternative 9D does not.
What is NED?
Projects developed in accordance with the federally funded National Economic Development (NED) plan must optimize flood damage reduction benefits consistent with protecting environmental quality and project benefits must exceed costs.
The USACE has preliminarily selected the 9D, T3 as the NED Plan based on the computation of highest Net Economic Benefits (NEB) that also has environmental and community acceptance. If highest NEB alternative is “unbuildable – not implementable,” the USACE can recommend another alternative with a lower NEB. As described below, the new alternatives are $125 million less expensive than the old alternatives.
What is an LPP?
A Locally Preferred Plan (LPP) has more elements and costs than the NED Plan. The local sponsors must pay 100% of the costs that exceed the NED project costs, effectively increasing the 25% local share of project costs.
What is an LRP?
Locally Requested Plans (LRPs) build upon the less expensive NED Alternative 9D and add elements deemed more acceptable to the community, one of these could become NED (maximum federal benefit/ match/ contribution) or LPP Plans ( NED + local support with 1:1 benefit to cost). Back to top
Alternatives 2A/T4 Described
2A with Bench Excavation
This is a 100-foot levee setback with bench excavation in reaches 2 and 4. This alternative has a 90% certainty of containing 100-year flood flows of 44,000 cubic feet per second.
New levees on both sides of the river will be set back and raised five feet above the existing levees, except in Reach 3.
- Reach 1 levees will be set back 100' on each side and rebuilt and raised. The existing riparian forest will remain intact. Bench excavation is not included in reach 1.
- Reach 2 levees will also be set back 100' and rebuilt. There can be no fully-developed riparian forest in this reach, but there will be vegetation and some trees. Extensive maintenance will be required. Some bench excavation will occur.
- Reach 3 through Watsonville and downtown Pajaro, levees will be rebuilt and raised in place by four feet. Some bench excavation will occur. There will be no fully-developed riparian forest.
- Reach 4 levees will be rebuilt and set back 100' on both sides. Existing riparian cover will be maintained. Some bench excavation will occur.
To view full-size click on image.
Vegetation in Reach 2 would have an n value of 0.047 (see the vegetation in the channel page for more information on n values).
Tributary Alternative T4
The Salsipuedes and Corralitos Creek Tributary Alternative T4 involves setback levees, floodwalls, rebuilt levees, and combinations of levees with floodwalls on top of levees. Currently there are no levees along most of Corralitos Creek, so in many areas, levees or floodwalls will be added. Alternative T4 includes the College Lake outlet works and Orchard Park Ring Levee design. In tight residential areas some floodwalls will be built instead of levees to reduce impacts to existing homes.
To view full-size click on image.
Alternative T-4 is a hybrid alternative with a 100-foot setback on the City of Watsonville side only. It would impact 65 acres, including 11 structures.
To view full-size click on image.
While alternatives 2A with bench excavation and T4 are still under consideration by the USACE decision documents (the General Reevaluation Report (GRR) and EIS/EIR, the USACE evaluation of this alternative indicates that they cannot be the Recommended USACE (NED) Project because they are too expensive and do not have a high enough Benefit-to-Cost ratio for Federal Participation.
Alternatives 9D/T3 Described
9D
This alternative is similar to alternative 2A with the following exception:
To view full-size click on image.
Tributary Alternative T3
Similar to alternative T4 with the following exception:
- Variable setback levees on the City of Watsonville side of the creeks. Ranges from 0-225'
- Includes Bench Excavation
- Requires 75 acres
- Avoids impact to existing residential structures in some areas by use of floodwalls instead of levees
- Includes Orchard Park ring levee
- Will replace three bridgs that act as dams during high water flows
To view full-size click on image.
Levee Height
The image below provides a visual representation of the 4' levee raise that is part of Tributary Alternatives T3 and T4.
The image below provides a visual representation of the 4-5' levee raise that is Mainstem Alternatives 2A.
Flood Inundation
The image below provides a visual representation of the flood inundation areas with 9D and T3 flood improvements.
To view full-size click on image.
Alternatives Benefit-to-Cost Summary
The tables below describe the Benefit-to-Cost summary for the two mainstem and tributary alternatives. Both 9D and T3 have a higher benefit-to-cost ratio than the 2004 alternatives 2A and T4. The USACE NED selected plans must be implementable and have the highest Benefit-to-Cost ratio.
Local Sponsor Concerns
The Local Sponsors generally agree with the NED Tributary Alternative T3 but not with the Pajaro Mainstem Alternative 9D. Local sponsors believe the tentativeley identified Pajaro Mainstem Alternative (9D) is not viable and have indicated that they will not sponsor this alternative.
Alternative 9D does not meet the stated sponsor objectives for alternatives that:
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Provide 100 Year Flood Protection from Murphy’s Crossing to the Ocean OR Provide 100 Year Flood Protection in the Urban Reaches and 50 Year Protection in the Agricultural Reaches,
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Provide equal flood protection on both sides of the Pajaro River; and
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Minimize the land take while addressing the needs of the environmental regulatory agencies,
Other concerns include:
- The alternative does not adequately address legacy levees that have been in place since 1949. The legacy levees (black lines in Reaches 1 and 4 below) have been determined to be geotechnically and seismically inadequate by the USACE and would not be under USACE jurisdiction in this alternative.
To view full-size click on image.
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Alternative 9D would require the local sponsors to maintain levees to their current level of protection. If the current level of protection is not maintained and levee failure occurs, local sponsors would be liable for damages to property owners. This amount of liability exposure is beyond the capacity of the local sponsors.
To view full-size click on image.
Locally Requested Plans
In response to the USACE proposed alternatives 9D and T3, the Local Sponsors have proposed four additional alternatives for incorporation into the GRR (General Reevaluation Report , a USACE of Engineers report that accompanies the EIR/EIS as the decision-making documents). These Locally Requested Plans (LRPs) build upon the less expensive NED Alternative 9D and add elements deemed more acceptable to the community, one of these could become NED (maximum federal benefit/ match/ contribution) or LPP Plans ( NED + local support with 1:1 benefit to cost).LRP 3
To view full-size click on image.
LRP 3 builds on alternative 9D and calls for rebuilding levees in Reaches 1 and 4 in place, providing no additional flood protection in Reaches 1 and 4.
LRP 4
To view full-size click on image.
LRP 4 builds on alternative 9D and calls for rebuilding levees in Reaches 1 and 4 with an additional 50’ setback, providing a 50 year Level of Protection.
LRP 5
To view full-size click on image.
LRP 5 builds on alternative 9D and calls for floodproofing Reach 1 facilities including water wells and water distribution system and rebuilding reach 4 levees with an additional 50’ setback to provide a 50 year Level of Protection in Reach 4
LRP 6
To view full-size click on image.
LRP 6 builds on alternative 9D and calls for Floodproof Reach 1 facilities and rebuilding Reach 4 levees in place, providing no increased level of flood protection in reach 4.
The table above compares the total costs of the 4 LRPs. More information on project costs is available in the Cost and Financing section of the website.
What's next for the Locally Requested Plans?
Benefit to cost ratio analysis is currently under way by the USACE. Montgomery Watson Harza(MWH) has estimated that the additional construction to exceed the estimated cost of 2A. NorthWest Hydraulics (NHC) is currently studying the potential impacts of these alternatives on flood area, depth and duration for flood events of varying sizes. The evaluation of all four LRPs will be included in the GRR/EIS that is currently being developed. The local sponsors will inform the broader community of the progress on these efforts and provide opportunities for input at strategic intervals.
To view full-size click on image.
The preliminary results will be available by the end of 2010.
What's next for Alternative 2A?
The local sponsors and community are working with the USACE to point out where benefits of this alternative are under estimated, including:
- Calculating agricultural losses, and
- Calculating water system losses.
If identified benefits can be increased, than 2A could become eligible as an Locally Preferred Plan.
What's next for the Project?
The next steps for the project are identifed below:
- USACE/Local Sponsors analyze new LRP Alternatives
- USACE revises draft GRR and EIR to include 4 LRP alternatives
- Release Public Review GRR and EIR
- Community, regulatory agencies and USACE decide whether to support the NED Plan or an alternate plan based upon existing alternatives or combination of alternatives contained in the EIS
- Community Chooses NED or LPP
- Public Vote for Local Share Financing
USACE Schedule
- Start Study LRP: 3/9/10
- Draft EIS: 8/27/12
- Final EIS: 12/31/12*
*The project sponsors are trying to accelerate this by a year.
