SANTA CLARA VALLEY WATER DISTRICT
STREAM MAINTENANCE PROGRAM
MITIGATION MONITORING AND REPORTING PROGRAM
(Appendix J of the SMP Document)
Santa Clara Valley Water District
5750 Almaden Expressway
San Jose, CA 95118-3686
August 10, 2001
I. INTRODUCTION
The purpose of this Mitigation Monitoring and Reporting Program (MMRP) is to verify implementation of the mitigation measures identified in the Stream Maintenance Program (SMP) in compliance with the California Environmental Quality Act Guidelines §15097.
The Stream Maintenance Program (SMP) is a program for conducting routine stream and canal maintenance within the jurisdiction of the Santa Clara Valley Water District (District). The program is intended to apply to three major activities, sediment removal, vegetation management, and bank protection; and a group of minor activities. See Figure MMRP-1 for the location of projected SMP activities in channels. All figures and tables are attached at the end of this report. The District is a special purpose governmental agency responsible for providing water supply and flood protection for Santa Clara County, California in a cost effective and environmentally responsible manner.
In the year 2001, an Environmental Impact Report (EIR) was prepared evaluating the environmental effects of the SMP (District 2001a). Table MMRP-1 summarizes the potentially significant effects of the SMP and incorporated mitigation measures. The EIR found that potentially significant impacts from SMP activities occurred in the following major categories: removal of wetland and riparian vegetation and associated disruption of wildlife and wildlife habitat including special-status species; disruption of geomorphic stream processes which could result in additional erosion or sedimentation; degradation of water quality; and disruption of cultural resources.
Many of these impacts could be avoided or minimized by the implementation of Best Management Practices (BMPs) when routine maintenance activities are conducted in streams and canals. A compensatory mitigation package is included in the SMP to replace wetland and riparian vegetation and preserve and restore watershed lands. A portion of this compensatory mitigation package is specifically designed to compensate for impacts to special-status species. The bank protection program includes its own mitigation program which will be implemented on a case-by-case basis according to the environmental conditions of and specific design for each site. BMPs, the stream vegetation compensatory mitigation package, and mitigation associated with the bank protection program are described below with references made to more detailed reports or attachments. Chapter 5 of the SMP document (District 2001b) also includes a more detailed description of these mitigation measures.
II. BEST MANAGEMENT PRACTICES
BMPs are methods that protect environmental quality or reduce environmental impacts from stream maintenance activities. BMPs are most often implemented at the time work on an individual routine maintenance activity is conducted in the field, however, they also can be implemented at the time of planning or design. Table MMRP-1 lists the specific BMPs which will be utilized to avoid, minimize or mitigate for potentially significant impacts of the SMP. The BMP code and short title are included in Table MMRP-1. Refer to the comprehensive list of BMPs included in Appendix G of the SMP document for a more lengthy description of each BMP. This appendix also includes a description on how BMPs are selected, monitored, reported and revised.
See the Reporting section below for additional information on the revision of and reporting on BMPs.
III. COMPENSATORY MITIGATION PROGRAM FOR STREAM VEGETATION
The SMP includes compensatory mitigation for impacts to 30 acres of tidal wetlands, 106 acres of freshwater wetlands and 66 acres of riparian vegetation. Table MMRP-2 summarizes the wetland and riparian mitigation program.
The level of temporary, repetitive impacts caused by routine stream maintenance activities and the appropriate level of permanent mitigation were determined by a one-time accounting method described in Chapter IV-B of the EIR. The types of wetland and riparian vegetation impacted are more thoroughly described in Chapter IV-B of the EIR. In general, the stream vegetation has been regularly disturbed by prior maintenance and construction activities and by surrounding urban land uses. Mature riparian trees are not removed. Impacts to riparian vegetation consists of removal of woody saplings which block flood conveyance.
The compensatory mitigation package was designed to compensate for the same or similar functions as those impacted. Guiding principles were established in Chapter 5 of the SMP document with the advice of the stakeholders and regulatory agencies to assist in development of the mitigation elements. Some of these guiding principles include: mitigation will match impacts by basin; larger, sustainable sites are preferable to smaller, fragmented sites; creation of freshwater and tidal wetlands must be included as part of the mitigation program; and other mitigation techniques such as invasive species control and land preservation are acceptable.
Additional information about each component in the stream vegetation mitigation package is briefly summarized below. Final designs for each mitigation component will be developed and submitted to the regulatory agencies for their review and approval. Detailed design is underway for several of these components, and some have received preliminary review by the regulatory agencies. Maintenance work is spread out over many years, and likewise, mitigation design and implementation will be spread out over a period of approximately 10 years.
A. Tidal Wetland Restoration
The Tidal Wetland Restoration component would establish 30 acres of tidal wetland by restoring Pond A4, a diked salt evaporation pond, to historical tidal marsh conditions. The pond is located along South San Francisco Bay, and bordered by Sunnyvale East and West Channels, and Guadalupe Slough. The restoration site is expected to support tidal wetland similar to or of higher quality than the tidal wetlands impacted by repetitive maintenance activities. The pond is under ownership of the District, and is currently leased to Cargill Salt Division to continue their salt production operations until 2002.
The tidal wetland restoration concept at Pond A4 consists of lowering the outboard levees or breaching them in several strategic locations to provide full tidal action to the site. It is anticipated that a mosaic of mud flat, tidal wetland, and upland habitats will be created. A combination of natural sedimentation processes and placement of dredge fill is proposed to accelerate restoration of wetland function to the site and create beneficial reuse of clean sediment excavated from tidal streams. Modification of Sunnyvale East Channel may be included in the design to improve its hydraulic performance and eliminate the need for future sediment removal and vegetation management for flood protection purposes.
The Pond A4 project will be coordinated with other large-scale tidal marsh restoration projects proposed for South San Francisco Bay. Because of ground subsidence, reuse of clean fill material may be necessary to supplement natural sedimentation in order for wetland features to develop in the short term. Control of perennial peppergrass, an invasive species that has infested brackish and freshwater marshes in the South San Francisco Bay, will be included.
Restoration at Pond A4 will create foraging habitat for black rail and clapper rail to compensate for impacts to these special-status species from SMP activities. Pond A4 is located immediately adjacent to existing areas used by these species.
Planning and design of the Pond A4 tidal restoration are currently underway, and the following milestones are projected: mitigation and monitoring plan for submittal to the resource agencies - May 2005, detailed design - May 2007, and construction - summer 2007. The first phase of restoration on the 300-acre pond will include 30 acres credited as mitigation for the SMP. A mitigation banking instrument and funding strategy will be developed, as well as a monitoring program.
B. Freshwater Wetland Creation
The Freshwater Wetland Creation component would create 14 acres of freshwater wetlands (also known as nontidal wetlands) at Los Capitancillos, Coyote Lakes Park Site 10A, and Church Pond Number 2. These sites are currently either fields of annual grasses or a nonfunctioning percolation pond which would be converted to seasonal or perennial wetlands at locations offstream, but directly adjacent to creeks.
The District will continue searching for additional sites for freshwater wetland creation. If additional sites are found, then the Stream and Watershed Protection component (described below) of the mitigation package will be reduced accordingly.
Although the freshwater wetland creation sites will not be in-stream as the impacted freshwater wetlands, they have an advantage of not being subject to routine disturbance from flood protection maintenance as the impacted sites are. These created wetlands will provide habitat for common local wildlife and wetland-related plants in a streamside setting. Because of their off-stream location, they will rely on water supplied from off-site sources, and will require management of water levels.
1. Los Capitancillos Site
The Los Capitancillos freshwater wetland creation site will consist of approximately 3 acres of off-stream freshwater seasonal or perennial wetlands adjacent to Guadalupe Creek in the Santa Clara Basin. The site, located near Coleman Road and Redmond Avenue in the City of San Jose, is currently an upland field of annual grasses and is owned by the District.
To create suitable conditions for development of a wetland, the site will be excavated. Water will be provided from the Almaden Valley pipeline and water control structures will be constructed to allow for adjustments of water depth and duration of inundation. Native hydrophytic species will be planted.
Preliminary investigations indicate that mercury levels are elevated in surface and shallow-depth soils on the Los Capitancillos site. The elevated levels are well below hazardous materials levels, but exceed wetland creation cover material levels recommended by the California Regional Water Quality Control Board. This situation is being investigated further; however, the likely solution is that soils not suitable for wetland surfaces will be removed from the site and replaced with clean soils.
This site will be developed in coordination with an adjacent project, the restoration of a meander configuration, and shaded riparian aquatic habitat on Guadalupe Creek for fisheries values. The Guadalupe Creek project is not part of the Stream Maintenance Program.
The Los Capitancillos site is currently under design, and is expected to be installed in the year 2002. The following milestones are projected: detailed design and mitigation and monitoring plan for submittal to the resource agencies - February 2002. A preliminary mitigation and monitoring plan was submitted to the resource agencies in June 1998 (District 1998).
2. Coyote Lakes Park Site 10A
The Coyote Lakes Park Site 10A freshwater wetlands creation site will consist of at least 7 acres of near perennial freshwater wetland. The site is located in the City of San Jose in the Santa Clara Basin. The land is owned by Santa Clara County and under the management of County Parks and Recreation Department. In consideration for funding for a County Parks and Recreation bridge, County Parks and Recreation has preliminarily agreed to provide the District with an easement for wetland or riparian creation and mitigation at the Parkway Site. The two agencies expect to complete an agreement on the funding/easement exchange within the next year.
The Coyote Lakes Park site is situated on the northeast bank of Coyote Creek, just upstream of the interchange of Highways 101 and 85. The site is bounded to the northeast by Highway 101, an abandoned gravel pond to the west, and Coyote Creek, a District percolation pond and the Coyote Parkway Lakes concession to the south.
The site currently consists of nonnative annual grassland habitat. The adjacent gravel pond, percolation pond, and Coyote Creek contain open water, emergent wetland, and mixed riparian forest. Preliminary investigations indicate the site has fine-textured soils appropriate for wetland habitat establishment.
On the Coyote Lakes Park site, approximately 7 acres of near perennial freshwater wetland will be created as mitigation credited towards the SMP. The full site will comprise a mosaic of habitat types including open water, emergent wetland and riparian. Emergent marsh species to be planted included California bulrush (Scirpus californicus) and common tule (Scirpus acutus). Narrow-leaved cattail (Typha angutifolia) and broad-leaved cattail (Typha latifolia) are expected to establish via natural recruitment.
Minimal grading would be required to create the wetland on this fairly level site. Water would be delivered to the site from the adjacent percolation pond. Preliminary information regarding flows in Coyote Creek and operation of the Coyote Creek percolation pond indicate that sufficient water from the pond would be available to support a wetland on the Parkway Site. Outflow from the site could be either to the gravel pond or Coyote Creek; however, outflows may not occur on a regular basis.
Other alternative design approaches may be evaluated during the project's final design phase. For example, the adjacent abandoned 16-acre gravel pond, located between the Parkway Site and Coyote Creek, could potentially be incorporated into the site design. Under this alternative, soil excavated from the Parkway Site could be used to raise the elevation of a portion of the gravel pond to an elevation appropriate for the establishment of emergent wetland vegetation.
Additional technical investigations, including studies of soils, hydrology, and cultural resources will need to be conducted to determine the detailed design. Although no archeological resources are known to occur at the site, Native American burials were found during deep excavation of a nearby site on Coyote Creek.
Coyote Lakes Park Site 10A is currently under design, and following milestones are projected: preliminary design and engineering report - June 2004, and start of construction August 2005. A mitigation and monitoring plan was submitted to the resource agencies in April 2001 (H.T. Harvey & Associates 2001). This report indicated it may be possible to create an additional 2 acres of freshwater wetland at the Parkway Site.
3. Church Pond No. 2
The Church pond freshwater wetland creation site will consist of converting open water at the Church Avenue groundwater recharge ponds into approximately 4 acres of freshwater wetland. Currently, three ponds provide approximately 42 acres of surface area dedicated to groundwater recharge at the intersection of Llagas and Church Avenues in the community of San Martin in the Pajaro River Basin. The property is under the ownership of the District.
The preliminary concept calls for a 4-acre earthen bench to be installed in one pond (No. 2) in a location known to be underlain by relatively impermeable soils. Shallow groundwater investigations of the Church Avenue ponds indicate the low-permeability substrates in Pond No. 2 are likely to have relatively low infiltration rates and not contribute substantially to overall recharge performance. Therefore, converting the primary purpose and management of this pond from groundwater recharge to wetland mitigation is not expected to result in substantial loss of groundwater recharge capability. The remainder of the pond's 15-acre surface area will remain open water used for percolation. Currently, the pond is often left dry.
The project will take advantage of the existing infrastructure, pond configuration, and water management to operate the Church pond system for dual percolation and wetland mitigation purposes. For purposes of creating the wetland area, water will be supplied to the ponds from Llagas Creek and is not expected to require a substantial alteration of recent District reservoir water releases or operations. Under current operation, stored water from upstream reservoirs flows downstream as far as Church ponds during the dry season. The preliminary concept calls for water to be routed to the pond system via an existing intake pipe between Pond No. 1 and Llagas Creek.
It may be necessary to construct a flashboard dam in the creek in order to divert the water. The flashboard dam would be installed and the diversion operated during the summer dry season. The flashboard dam will be designed and operated so as to not obstruct fish passage and not cause bank erosion. This reach of Llagas Creek has limited potential to be a migratory corridor for steelhead trout. If necessary, the water diversion structure will be designed to allow for fish passage throughout the year, by installation of a fish ladder or other means, thus avoiding impacts to migrating steelhead. The cumulative effect of another fish ladder on Llagas Creek will be considered during design of this project, and alternative means to either divert water from Llagas Creek or to provide fish passage around a water intake structure will be considered. The intake pipe will be screened to prevent diversion of fish into the ponds. Alternative water delivery methods, such as an infiltration gallery, will be explored during the planning phase. The design will create water levels on the bench of an adequate depth for wetland vegetation and will reliably control surface water elevation.
Construction of the Church pond wetland creation project is expected to begin in the summer of 2003. The following milestones are projected: mitigation and monitoring plan for submittal to the resource agencies - February 2003, and detailed design June 2003.
C. Stream and Watershed Protection
The Stream and Watershed Protection component includes the purchase of approximately 820 to 1080 acres of land and conservation easements to preserve, protect, and improve streams and their associated watersheds in the county over the next 10 years. The Stream and Watershed Protection component, along with the Freshwater Wetland Creation component, mitigate for SMP impacts to freshwater wetlands. The District will continue searching for additional sites for freshwater wetland creation as described above. If additional suitable freshwater wetland creation projects are identified, then the Stream and Watershed Protection component of the mitigation package would be reduced by approximately 10 acres for every additional 1 acre of freshwater wetland creation.
The Stream and Watershed Protection Program will provide long-term protection and improvement of unique and valuable local stream resources together with their watersheds, in a largely self-sustaining setting. The primary focus is on streams that are in a fairly undisturbed state and generally good ecological condition. Streams that are currently degraded, but that can be returned to good ecological condition, can also be included in the Program.
The Stream and Watershed Protection Program consists primarily of land acquisition, but also provides for some restoration, rehabilitation and/or management projects (restoration projects). Properties containing streams and their immediate watersheds will be acquired. Restoration projects that would benefit stream resources would be conducted on selected acquisition projects or other qualifying lands, as described in Attachment A.
Of the 92 acres of mitigation credit to be provided by Stream and Watershed Protection, acquisition is projected to provide 82 acres of credit, and restoration projects are projected to provide 10 acres of credit. The relative contributions of these sub-components may be adjusted based on opportunity and resource needs identified as the mitigation program progresses.
Acquisition of these lands will most likely be accomplished by the District's donation of funds to park and open space agencies, land trusts, and other land conservation organizations that will ultimately own title or easement and manage the property. The District's contribution will typically provide partial funding of a larger acquisition, however, in some cases the District may choose to purchase and retain sole ownership or easement. Long-term land use and management conditions will be specified as part any partnership purchase agreement. Land will be monitored periodically to ensure that the terms of acquisition continue to be met.
The District will evaluate each proposed acquisition under a standard set of criteria established to ensure that the mitigation goals are met and mitigation credit is obtained. To qualify for consideration under this Stream Maintenance Program, the land must meet a standard set of core criteria (e.g., the land must include a stream, must be located in a watershed related to District streams, would not otherwise be purchased by the District, and is available from a willing seller). Additional criteria will be used to determine the relative priority for acquisition of available parcels.
Each acquired property will be further evaluated to determine if the stream resources would benefit from restoration or management actions. Examples of the many types of restoration or management actions that could be undertaken to improve stream health include: removal of nonnative riparian plant species and revegetation with native species, repair and rehabilitation of denuded or otherwise degraded stream segments, replacement of in-stream road crossings with more environmentally-sensitive crossings, installation of erosion control measures on roads adjacent to streams (dirt or paved roads run parallel to most sizeable streams in the county), and installation of fencing to limit cattle access to the riparian area.
Of the lands acquired under the Stream and Watershed Protection component, 108 acres will be specifically targeted for protection of riparian and upland habitat associated with a minimum of 2 streams that are known to support California red-legged frog and western pond turtle. All 108 of these acres will occur in Santa Clara County with at least one site in the Santa Cruz Mountains and one site in the Diablo Range.
The Program will be implemented over 10 years. Acquisition will be completed, and restoration projects will be identified in order to meet the interim milestones. The milestones are:
Attachment A contains includes a detailed mitigation and monitoring plan for the Stream and Watershed Protection Program.
D. Control of Giant Reed
The Giant Reed Control component would remove a non-native, invasive plant of riparian areas, giant reed, from 125 acres in the county. This component also includes mapping, revegetation, monitoring, and educational elements. Of the total acres from which giant reed is removed, 66 acres would be credited towards the 66 acres of impacts to riparian vegetation. An additional 59 acres of giant reed control is proposed to compensate for any lag time between maintenance impacts to stream vegetation and implementation of the mitigation components.
Giant reed is a highly invasive non-native species that infests creeks and adjacent habitat throughout Santa Clara County. Giant reed displaces native vegetation thus reducing the quality of riparian habitat. It contributes to localized flooding by blocking channels. Since giant reed displaces open water and native riparian and wetland plant communities of freshwater streams, its control is appropriate compensation for impacts to sapling riparian vegetation caused by channel vegetation management.
The following elements are included in the Giant Reed Control Program:
The location of giant reed removal will be identified in the first few years of the program as a result of the mapping and prioritization elements described above. Initial control will consist of removal of biomass, appropriate disposal of biomass, and treatment of clumps with an approved herbicide. Typical herbicide control would consist of applying glyphosate (primarily in an aquatic formulation) in a concentrated form to freshly cut stumps. In areas with significant remaining riparian vegetation, natural re-colonization of the treated site is expected after persistent control of giant reed clumps. Revegetation with site-appropriate native species will be implemented in areas where natural revegetation does not occur or is unlikely to occur due to the absence of adjacent parent stock. The goal of revegetation is to have 40% native cover in the treated area within 5 years after the end of treatment.
On an average basis, approximately 10 to 15 new acres of giant reed will be controlled each year. Attachment B contains includes a detailed mitigation and monitoring plan for the Giant Reed Control program.
IV. BANK PROTECTION MITIGATION
The SMP includes a bank protection program that avoids impacts to the greatest extent possible and incorporates mitigation to balance impacts that can not be avoided. The impact of bank protection depends on the type of work done and the sensitivity of the environment where the work is done. This work type/environment relationship is described in further detail in revised Appendix E of the SMP document. Appendix E of the SMP also includes a bank protection impact assessment matrix to evaluate the environmental impact of bank protection and determine when mitigation is required.
When the bank protection impact assessment matrix indicates that mitigation is required, an equivalent area of bank vegetation will be provided. To further reduce the adverse effects of bank protection, the District will mitigate for all impacts for impervious hardscape and for unvegetated rock bank protection at a ratio of 3:1 and for all vegetated rock at a ratio of 1:1 regardless of the determination of the impact assessment matrix.
Mitigation for both in-stream and stream-side impacts will consist of revegetation consistent with the Protocol for Revegetation Associated with Bank Protection in Appendix E of the SMP.
BMP 2.8 also provides that native trees between 6 and 18 inches in diameter at breast height dbh (diameter at breast height) that are lost due to bank protection impacts will be replaced at a ratio of 3:1. Non-native trees between 6 and 18 inches dbh will be replaced at a ratio of 1:1 with appropriate native species. Trees removed for installation of bank protection measures shall be replaced at the site, if feasible, or at the mitigation site created for that bank protection activity.
Mitigation for the bank protection program will be implemented on a project-by-project basis. All impacts and credits as a result of the bank protection program will be measured by area and the ongoing totals will be reported in the annual report.
V. RESPONSIBLE PARTIES
The Watershed Management Division of the District, under the guidance of Mr. Jim Fiedler, Deputy Operating Officer, has the responsibility for implementing and monitoring the SMP mitigation measures.
VI. REPORTING
As described further in Chapter 3 of the SMP document, each November, District staff will hold a "Lessons Learned" meeting to evaluate the SMP program including the BMPs and mitigation. Projects from the preceding season will be reviewed, and modifications to BMPs considered.
An annual report detailing what routine stream maintenance work was accomplished in the prior construction season will be submitted to the District's Chief Executive Officer, the US Army Corps of Engineers, the US Fish and Wildlife Service, California Department of Fish and Game, San Francisco Bay Conservation and Development Commission, National Marine Fisheries Service, the San Francisquito Joint Powers Authority and the Regional Water Quality Control Boards at the end of the maintenance season (prior to January 1) which will specify which projects were completed for the year including type of work, location, and size of the project. Sediment removal, vegetation management, and bank protection work which has been repeated under the SMP will be distinguished from areas where such work is being undertaken for the first time under the SMP. Any modifications of BMPs recommended at the annual lessons learned meeting will be summarized in the annual report.
In addition to reporting on the maintenance activity completed for the year, the District will also provide reporting on the implementation of the mitigation program, including maps showing the location of compensatory mitigation sites, a description of the current stage in the planning and implementation schedule, progress towards success criteria, and a general summary of maintenance of mitigation sites.
For the first 5 years of the program, the District will provide the agencies with a tour of representative work areas for that year and all mitigation sites. This tour will take place after completion of the work season. Preconstruction photographs will also be provided. The District's Geographic Information System (GIS) may be utilized as a tool for reporting annual work activities and implementation of mitigation projects.
VII. REFERENCES
District. 1998. Urgent Sediment Removal Project - Compensatory Wetlands Mitigation and Monitoring Plan. Los Capitancillos Freshwater Wetlands Mitigation site and Pond A-8 Tidal Wetlands Mitigation Site. June 8, 1998.
District. 2001a. Final Environmental Impact Report and Stream Maintenance Program Report for the Multi-Year Stream Maintenance Program. August 2001.
District. 2001b. Draft Environmental Stream Maintenance Program. March 2001. (And any subsequent updates).
H.T. Harvey & Associates. 2001c. Coyote Creek Parkway Wetland Mitigation Site - Mitigation and Monitoring Plan. Revised May 1, 2001.
Table MMRP-1
Summary of Potentially Significant Impacts and Mitigation Incorporated into the SMP
Key to Table:
Note: the full text of the BMPs can be found in Appendix G of the SMP.
| Impacts | BMP Code | Short Title | Activity |
| Unavoidable Adverse Impacts that would Remain after Mitigation | |||
| IV-B. Biology | |||
| Impact Bio-4: The cumulative impact of sediment removal and vegetation management would fragment wildlife habitat. | 1.13 | Prevent Scour Downstream of Sediment Removal | SR |
| 2.1 | Minimize vegetation removal | All | |
| 3.6 | Remove Sediment from One Side of Large Channels in Alternate Years at Selected Sites | SR | |
| Off-site Compensatory Mitigation | |||
| Impacts That Would Be Mitigated to Less than Significant | |||
| IV-A. Geomorphology | |||
| Impact Geo-1. Sediment removal in certain locations may increase erosion downstream of the removal site. | 1.13 | Prevent Scour Downstream of Sediment Removal | SR |
| Impact Geo-2. Elimination of in-channel vegetation may increase sediment accumulation downstream. | 1.14 | Minimize Sediment Transport Downstream from In-channel Herbicide Sites | VM |
| Impact Geo-3. Removal of vegetation may increase local erosion. | 1.16 | Minimize Local Erosion increase from In-channel Vegetation Removal | VM |
| Impact Geo-4. Bank protection measures can direct flows downstream, resulting in new erosion and bank instability problems. | 1.15 | Prevent Erosion Downstream of Bank Protection Sites | BP |
| Impact Geo-5. Removal of woody debris may reduce channel bed diversity. | 3.9 | Retain Woody Materials and Vegetation | BP, MM |
| IV-B. Biology | |||
| Impact Bio 1: Sediment removal and vegetation management would impact in-stream wetland and riparian vegetation. | 1.13 | Prevent Scour Downstream of Sediment Removal | SR |
| 2.1 | Minimize vegetation removal | All | |
| 3.6 | Remove Sediment from One Side of Large Channels in Alternate Years | SR | |
| Off-site Compensatory Mitigation | |||
| Impact Bio-2: The project could result in removal of heritage-sized trees. | 2.1 | Minimize vegetation removal | All |
| 2.2 | Minimize Stream Access Impacts | SR, BP | |
| 2.8 | Replace heritage trees | BP | |
| 3.9 | Retain Woody Materials and Vegetation | BP, MM | |
| Impact Bio-3: Program implementation could introduce invasive plant species into native, riparian, or wetland habitat areas. | 2.1 | Minimize vegetation removal | All |
| 2.5 | Planting | BP | |
| 2.6 | Mulching | BP | |
| 2.7 | Seeding | BP | |
| Impact Bio-5: Bank protection would cause a loss of riparian vegetation functions and values, which would cause a significant cumulative adverse impact on wildlife and fisheries habitat. | 2.1 | Minimize vegetation removal | All |
| 2.3 | Minimize Hardscape in Bank Protection Design | BP | |
| 2.5 | Planting | BP | |
| 3.5 | Minimize Loss of Aquatic Habitat from Bank Protection work | BP | |
| 3.14 | Maintain or Provide Escape Cover | BP | |
| 1:1 and 3:1 offsite mitigation plantings for planted rock and impervious/unplanted rock designs, respectively | |||
| Impact Bio-6: The cumulative effects of resuming herbicide use in the Pajaro River Basin would substantially reduce the value of the habitat for wildlife. | 2.1 | Minimize vegetation removal | All |
| 3.2 | Minimize Impacts to Breeding Birds Via Site Assessments and Avoidance Measures | All | |
| 3.18 | Herbicide use in aquatic areas | VM | |
| 3.19 | Develop a biodiversity monitoring program | All | |
| Off-site Compensatory Mitigation | |||
| Impact Bio-7: Chemical use by the District, especially for rodent control, could adversely affect non-target species. | 2.1 | Minimize vegetation removal | All |
| 3.1 | Minimize Impacts to Special-status Animals Via Site Assessments and Avoidance Measures | All | |
| 3.18 | Herbicide Use in Aquatic Areas | VM | |
| 3.2 | Minimize Herbicide Impacts on Non-target species | VM | |
| 3.21 | Minimize Rodent Control Impacts on Non-target Species | MM | |
| 4.7 | Herbicide Use Requirements | VM | |
| Impact Bio-8: Maintenance activities could introduce invasive wildlife species. |
3.4 |
Mitten Crab Control Measures | SR |
| Impact Bio-9: Maintenance activities could directly harm nesting species protected under the Migratory Bird Treaty Act and other statutes. | 2.1 | Minimize vegetation removal | All |
| 3.2 | Minimize Impacts to Breeding Birds Via Site Assessments and Avoidance Measures | All | |
| 3.9 | Retain Woody Materials and Vegetation | BP, MM | |
| 3.19 | Develop a Biodiversity Monitoring Program | All | |
| Impact Bio-10: Maintenance work conducted in channels could substantially interfere with migration, spawning, incubating, or rearing habitat for native aquatic species. | 2.2 | Minimize Stream Access Impacts | SR, BP |
| 3.7 | Salvage Native Aquatic Vertebrates from Dewatered Channels | SR, BP | |
| 3.9 | Retain Woody Materials and Vegetation | BP, MM | |
| 3.11 | Avoid Dewatering an Entire Isolated Stream Reach | SR, BP | |
| 3.12 | Maintain Low-flow Fish Passage | SR, BP | |
| 3.13 | Remove Temporary Fills as Appropriate | SR, BP | |
| 3.14 | Maintain or Provide Escape Cover | SR, BP | |
| 3.15 | Restore Riffle and Pool Configuration of Channel Bottom | SR, BP | |
| 3.16 | Restore Spawning Gravels in Work Site Areas | SR, BP | |
| 3.17 | Reuse Sediments and Gravels As Appropriate | SR | |
| Impact Bio-11: Temporarily suspended sediment can adversely affect aquatic or semi-aquatic species. | 1.1 | Conduct Work During Low Flow Periods | All |
| 1.2 | Tidal Work Areas | SR | |
| 1.3 | Dewater/ Bypass Water at Non-tidal Sites | SR, BP | |
| 1.4 | Avoid Erosion When Restoring Flows | SR, BP | |
| 1.5 | Erosion and Sediment Control Measures | BP | |
| 1.6 | Use of Wheel and Track Mounted Vehicles in Stream Bottoms | SR, BP | |
| 1.7 | Pump/
Generator Set Operations and Maintenance |
SR, BP | |
| 1.8 | Handle Sediments So As to Minimize Water Quality Impacts | SR | |
| 1.9 | Soil Stockpiles | SR | |
| 1.12 | Groundwater Management | SR, BP | |
| 1.14 | Minimize Sediment Transport Downstream from In-channel Herbicide Sites | VM | |
| 1.15 | Prevent Erosion Downstream of Bank Protection Sites | BP | |
| 2.2 | Minimize Stream Access Impacts | SR, BP | |
| 3.1 | Conduct In-Channel Work During the Dry Season | SR, BP | |
| Impact Bio-12: Sediment Removal would adversely affect special-status species. | 1.3 | Dewater/ Bypass Water at Non-tidal Sites | SR, BP |
| 1.4 | Avoid Erosion When Restoring Flows | SR, BP | |
| 2.4 | Minimize Impacts to Special-status Plants by Avoidance Based on Site Assessments | All | |
| 3.1 | Minimize Impacts to Special-status Animals Via Site Assessments and Avoidance Measures | All | |
| 3.2 | Minimize Impacts to Breeding Birds Via Site Assessments and Avoidance Measures | All | |
| 3.3 | Avoid serpentine habitat | All | |
| 3.6 | Remove Sediment from One Side of Large Channels in Alternate Years | SR | |
| 3.7 | Salvage Native Aquatic Vertebrates from Dewatered Channels | SR, BP | |
| 3.9 | Retain Woody Materials and Vegetation | BP, MM | |
| 3.1 | Conduct In-Channel Work During the Dry Season | SR, BP | |
| 3.11 | Avoid Dewatering an Entire Isolated Stream Reach | SR, BP | |
| 3.12 | Maintain Low-flow Fish Passage | SR, BP | |
| 3.15 | Restore Riffle and Pool Configuration of Channel Bottom | SR, BP | |
| 3.16 | Restore Spawning Gravels in Work Site Areas | SR, BP | |
| 4.5 | Vehicle and Equipment Cleaning | All | |
| 6.1 | Spill Prevention | All | |
| 6.4 | Vehicle and Equipment Fueling | All | |
| 6.5 | Vehicle and Equipment Maintenance | All | |
| Impact Bio-13. Vegetation Management would adversely affect special-status species. | 1.14 | Minimize Sediment Transport Downstream from In-channel Herbicide Sites | VM |
| 2.1 | Minimize vegetation removal | All | |
| 2.2 | Minimize Stream Access Impacts | SR, BP | |
| 2.4 | Minimize Impacts to Special-status Plants by Avoidance Based on Site Assessments | All | |
| 3.1 | Minimize Impacts to Special-status Animals Via Site Assessments and Avoidance Measures | All | |
| 3.2 | Minimize Impacts to Breeding Birds Via Site Assessments and Avoidance Measures | SR, BP | |
| 3.3 | Avoid serpentine habitat | All | |
| 3.7 | Salvage Native Aquatic Vertebrates from Dewatered Channels | SR, BP | |
| 3.1 | Conduct In-Channel Work During the Dry Season | SR, BP | |
| 3.18 | Herbicide Use in Aquatic Areas | VM | |
| 3.2 | Minimize Herbicide Impacts on Non-target species | VM | |
| 4.7 | Herbicide Use Requirements | VM | |
| Impact Bio-14. Bank Protection would adversely affect special-status species. | 1.5 | Erosion and Sediment Control Measures | BP |
| 2.3 | Minimize Hardscape in Bank Protection Design | BP | |
| 2.4 | Minimize Impacts to Special-status Plants by Avoidance Based on Site Assessments | All | |
| 2.5
2.6 2.7 |
Planting, Mulching, Seeding | BP | |
| 3.1 | Minimize Impacts to Special-status Animals Via Site Assessments and Avoidance Measures | All | |
| 3.2 | Minimize Impacts to Breeding Birds Via Site Assessments and Avoidance Measures | All | |
| 3.3 | Avoid serpentine habitat | All | |
| 3.7 | Salvage Native Aquatic Vertebrates from Dewatered Channels | SR, BP | |
| 3.14 | Maintain or Provide Escape Cover | BP | |
| 3.19 | Develop a Biodiversity Monitoring Program | All | |
| Impact Bio-15: Minor Stream Maintenance Activities would adversely affect special-status species. | 2.4 | Minimize Impacts to Special-status Plants by Avoidance Based on Site Assessments | All |
| 3.1 | Minimize Impacts to Special-status Animals Via Site Assessments and Avoidance Measures | All | |
| 3.2 | Minimize Impacts to Breeding Birds Via Site Assessments and Avoidance Measures | All | |
| 3.3 | Avoid serpentine habitat | SR, BP | |
| 3.7 | Salvage Native Aquatic Vertebrates from Dewatered Channels | SR, BP | |
| 3.9 | Retain Woody Materials and Vegetation | BP, MM | |
| 3.1 | Conduct In-Channel Work During the Dry Season | SR, BP | |
| 3.21 | Minimize Rodent Control Impacts on Non-target Species | MM | |
| IV-D. Public Safety | |||
| Impact WQ-1. Erosion of mercury containing sediment. |
1.10 |
Avoid Exposing Soils with High Mercury Levels | BP |
| Impact Haz-1. Preventing exposure of mercury during bank protection. | |||
| IV-E. Cultural | |||
| Impact Cul-1: Disruption of Cultural Resources
Impact Cul-2: Disruption of Native American Burials |
7.1 |
Discovery of Cultural Remains or Historic Artifacts | All |
|
7.2 |
Review of Projects with Native Soil | All | |
Table MMRP-2
Compensatory Stream Vegetation and Special Status Species Mitigation
| Mitigation Component | Location | Size of Mitigation | Compensates for
Impacts to: |
Description | Installation Date |
| Tidal Wetland Restoration | Pond A4 | 30 acres | 30 acres of tidal wetlands:
Will provide foraging habitat for California clapper rail and black rail. |
Restore diked salt evaporator pond to historical tidal marsh conditions | 2007 |
| Freshwater Wetland Creation | Three sites currently identified: | 14 acres of freshwater wetland in
stream channels:
|
|||
|
3 acres, Santa Clara Basin | Convert annual grasslands to seasonal or perennial wetlands adjacent to Guadalupe River | 2002 | ||
|
7 acres, Santa Clara Basin | Convert ruderal grasslands to near-perennial wetlands adjacent to Coyote Creek | 2005 | ||
|
4 acres, Pajaro River Basin | Convert open water in inactive percolation pond to wetland bench | 2003 | ||
| Stream and Watershed Protection | Undeveloped parcels with streams | Approx. 820 to 1,080 acres purchased and additional restored | 92 acres of freshwater wetlands:
|
Preserve, protect, and improve streams and associated watersheds | As lands become available in first 10 years. |
| Giant Reed Control | Throughout county | 125 acres | 66 acres of riparian vegetation
from vegetation management:
And, 59 acres of the total 125 acres of Giant Reed Control is being provided for lag time in implementing and effective functioning of mitigation components |
Control giant reed outbreaks and provide associated mapping, revegetation, education, and coordination throughout county | 2002-
2012 |