San Francisco Bay Region

Michael Josselyn, PhD
Wetlands Research Associates
2169-G East San Francisco Blvd.
San Rafael, CA 94901

Subject: Application for 401 Water Quality Certification for Gateway Valley Development/Montanera Project, Orinda, Contra Costa County

Dear Dr. Josselyn:

Regional Board staff have reviewed the additional application materials, dated February 5, 1999, and the replacement maps submitted on February 16, 1999, in response to our January 4, 1999, comment letter. Staff have also reviewed the buffer overlay map, received April 8, 1999, which was requested on February 23, 1999, when staff determined that February 16th maps were missing some requested information. Staff also met with yourself and Roland Aberg, on January 19, 1999 to discuss our January 4th letter.

The materials are relative to the proposal by Orinda Gateway, LLC, to construct 225 homes, an 18-hole championship golf course, a swim and tennis club, and other associated facilities on a 978-acre panel, known as Montanera Development. The parcel is located in Contra Costa County, and the majority of the parcel is located in the City of Orinda. Orinda Gateway, LLC, (applicant) has applied to the Board for Clean Water Act Section 401 certification that the proposed project will not violate State water quality standards.

Board staff are also in receipt of several recent letters from the U.S. Army Corps of Engineers (Corps); one, dated February 16, 1999, which comments on the revised mitigation submittal and the other, dated April 7, 1999, which provides a summary of a Corps April 5th meeting with the applicant regarding Corps review of the proposed project. The Corps has also provided Board staff with a copy of your April 9, 1999, letter and attachments addressed to Cay Goude, USFWS, concerning the proposed project's Biological Opinion. Staff will refer to these items in this letter.

As we stated in both our May 4, 1998 and January 4, 1999, letters, staff have determined that the applicant has not yet demonstrated that potential impacts to both waterbody acreage and functions have been avoided to the maximum extent practicable as outlined in U.S. EPA's Section 404(b)(1), "Guidelines for Specification of Disposal Sites for Dredge or Fill Material," dated December 24, 1980. Under these Guidelines, the applicant is responsible for proving that no practicable alternative is available to avoid filling, unless the project is water dependent.

In response to Board staff questions concerning the alternatives analysis, the applicant has submitted information which discusses why 500 acres was the lower limit to consider a site appropriate to meet the overall project purpose. The applicant also stated that the guidelines state that practicability is determined by cost, existing technology, and logistics in light of the overall project purpose. They conclude that all of these elements involve some form of economics.

Aside from considering other constraints, staff concludes that the applicant believes that economic feasibility is the key determinant of practicability. While economic feasibility is a key indicator, it appears that economic profit rather than feasibility has been used to determine whether an alternative was practicable. Staff are concerned that alternatives meeting an economic feasibility test, and with reduced impacts to jurisdictional waterbodies compared to the preferred alternative may have been rejected because of the negative impacts on profits.

While staff recognizes that certain on-site alternatives proposed in the February 19, 1998, analysis might result in different/additional environmental impacts, staff believe that the applicant should explore on-site alternatives which would reduce the project size and minimize impacts to waters, but still allow the applicant to meet the basic overall project purpose and make a profit. This might be accomplished by a reduction in the number of housing lots, reduction in lot size, reduction/removal of the swim/tennis facility, and/or building a 9-hole instead of an 18-hole championship golf course.

A portion of the proposed project, the driving range, occurs on property currently owned by East Bay Municipal Utility District (EBMUD). The applicant also proposes to create a watershed demonstration park, and move or expand the playfields and parking areas on the EBMUD parcel. While the applicant states that they are committed to obtaining this 230-acre parcel, as of this date the land has not been purchased. During our January 19th meeting with the applicant's consultants, staff was assured that a letter detailing the agreement/commitment of EBMUD to agree to the land use would be available by March 1999. While the use of the EBMUD lands is part of the applicant's plan to build the proposed project, we refer to our January 4th letter in which staff discuss the details of the proposed project's draft Final Development Plan (FDP) which shows two matrices, one with the EBMUD parcel and the other without it. These matrices show that the project could be constructed with or without the EBMUD parcel. Again, staff concludes that the applicant may be able to meet the overall purpose without the EBMUD property, thus avoiding impacts to waters of the U.S. located on this property. However, if the applicant is committed to obtaining the EBMUD property, staff recommends that the applicant consider project alternatives in which the number of playfields and parking spaces stay the same, but are moved to the EBMUD lands and using the newly available parking space along Gateway Boulevard to relocate other project amenities to this area, providing further reduction to the project site's waterbodies.

Staff have reviewed the Quercus Creek (EBMUD Channel) Conceptual Design, February 24, 1998. This is the proposal for creek restoration on the land currently owned by EBMUD. The last page of the document entitled, "Watershed Demonstration Park Conceptual Design," shows several trail crossings and an entry bridge for the road over several creeks within the project site. Board staff have not received a jurisdictional delineation maps for the waterbodies within this area. In addition, staff would like to see cross sections and designs for these bridge crossings, as there may be potential impacts to waterbodies which will require mitigation.

Quarry Parcels A & B

In order for the Board to make a determination on potential impacts to water quality, staff requested details concerning development Parcels A, B and H. The applicant provided a sketch of lot lines and roads for Parcel H on the map that was requested. However, Parcel A and B (the quarry parcels) lack any detailed drawings. The applicant states that Parcels A and B are to be entirely regraded for the purpose of land development and the precise plans are being developed. The applicant also states that BMPs will be used to protect water quality. This is insufficient for staff to determine potential impacts and whether those impacts have been mitigated. Due to the steepness of the quarry parcel staff is concerned about the stability of the three created drainage swales which are being claimed for mitigation credit and as a wildlife corridor. Staff is unable to determine the number and placement of road crossings, and the potential impacts, to these created drainages. Staff has concerns over the number of stormdrain outfalls and impacts caused by potential changes in storm-water runoff quantity and quality in these created drainages. It is unclear to staff what, if any, buffer zone will occur along these drainages and how close housing lots will be located to these drainages.

The applicant has stated that the many bridges which will be constructed on the site's creeks and drainages are "clearspan". The applicant has submitted drawings which show precast spans which appear to be arched culverts with natural channel bottoms. The submitted design states that the bridges will be "at least 6 ft above the drainage thalweg" and will have wing walls which rest on the creek embankments. While some of the site's tributaries are small in width, staff believe that the proposed precast spans will impact the site's waterbodies either directly or indirectly. Potential impacts include a permanent reduction in the floodplain and floodflow capacity, reduction/removal of wildlife corridor (especially during high flow events), impact to vegetation by wing walls placement, channel incision, and future bank stabilization structures needed to protect the wing walls. It is also unclear if dewatering of the creeks and operation of heavy equipment in the creeks will be necessary during bridge installation.

The applicant also submitted photographs, Attachments A & H, which depict examples of a golf cart bridge, residential driveway, or pedestrian pathway being woven through existing vegetation. The applicant claims that these bridges would be clearspan over the creekbed. However, it appears from the photographs that these bridges require several piers/piles to support them. These piers/piles are potential impacts to the site's waterbodies.

In response to staff's request for information concerning potential impacts of trail construction to waters of the U.S. on PG&E lands, the applicant states that "the trails on PG&E property will not result in any fill to jurisdictional "waters or wetlands"... Because no fill is required, the applicant is not requesting any permit from the Corps or certification for the RWQCB for the trail." The applicant has submitted no information which identifies the boundary of Corps jurisdiction. In addition, the Regional Board has jurisdiction over all waters of the State, as defined in the California Porter-Cologne Water Quality Control Act. The jurisdiction can extend beyond the limits of Corps jurisdiction. Board staff are requesting that you submit drawings for the proposed tributary crossings on PG&E land, to enable staff to determine if the proposed crossings have any potential impacts to waters of the State.

Staff requested that the tentative subdivision map be submitted for review. The applicant states in their submittal that "it is not in the best interest of the applicant and the RWQCB to proceed with detailed plans without the Board's official review of the project." However, the Corps' April 7, 1999 letter outlines the Corps process and permit decision and the information that is needed. In this letter, Item 1d, Other Agency Information, states that the City of Orinda must approve the Tentative Map and that a copy of the Map will be provided to all the agencies to aid in understanding the final project design. If the Corps is waiting for the Tentative Map prior to making a permit decision, the Board must also wait and review the Map prior to making a decision. This will ensure that Board staff reviews and is issuing a certification for the same project which the Corps is permitting. The applicant will need to submit an approved Tentative Map prior to the Board considering the item for certification. However, a workshop can be held before the Map submittal.

The applicant submitted a description for the water storage pond to be located above the golf maintenance facility and adjacent to a tributary to Moraga Creek. The pond will be supplied by EBMUD and will not impact runoff to Moraga Creek. However, staff refers the applicant to its April 9, 1999, letter to Cay Goude of the USFWS and attachment entitled "Section 7 Consultation-Montanera Project." Page 3 of the attachment Item 1a, under "Suggested Reasonable and Prudent Measures (Draft)," states that details for the proposed on-site, subsurface water storage tank, and the proposed expansion of the Laguna Reservoir shall be included in the submission to the USFWS. These appear to be proposed water storage facilities beyond those discussed in application materials submitted to the Board. In absence of information on these, Board staff are concerned that they may have potential impacts to jurisdictional waters. The Board requests that the applicant submit details, including location maps and water sources, for both items.

Brookside Park has not yet been designed in detail. However, programmatic elements have been identified, and the applicant has submitted a sketch of the preliminary plan (Attachment B of the submittal). Items include a new park access road, parking for 25 cars, activities pavilion, bike and pedestrian trails, activity areas and picnic areas adjacent to the creek, and a pond amenity at the end of the park. The applicant states that the existing farm use area will be replaced by a controlled use that would greatly enhance water quality in the Brookside drainage. Staff finds little evidence for this statement, as it is often difficult to control use within a public area. From the details submitted, staff is concerned that the park may actually increase impacts to Brookside Creek. There are two areas within the park which are labeled "activity areas", one of which Brookside Creek runs directly through. Staff concludes that an activity area would have to be maintained in some form, i.e. concrete, gravel, or irrigated/mowed grasslands.

The applicant's description of Brookside Park elements also states that the pavilion will be constructed on piers, if necessary. The applicant provides no details as to why this might be necessary. It is also unclear where the pavilion will be placed. The drawing shows the structure on the south side of the creek, even though other materials state that the pavilion will be built on the north side where farm buildings are located. Staff would encourage placement on the north side to reduce car traffic across the creek to the pavilion. Is it necessary for the footpath to cross the creek and then cross back over approximately 25 feet downstream? Is it possible to remove the other crossing, reducing impacts? Also, will the pond amenity become a jurisdictional water and will it affect runoff to Brookside Creek?

Staff is also concerned about elements of the park and potential impacts to the California red-legged frog. A letter from Jeff Froke, an attachment to the USFWS letter, includes a statement that Dr. Jennings concluded that only the riparian reaches of Brookside Creek below the pool site showed promise of even marginal aestivaton habitat. Brookside Park will be within this riparian reach. In addition, the latest map submittal shows an emergency access road which circles around the "avoided frog mitigation pond" and cuts across two golf fairways. This road was not shown on the previous map submittal. While the proposed access road is placed in the same location as the farm road which currently exists, staff is concerned that there may need to be a change in grade to accommodate the new road and placement of the golf course fairways. Will the new road be constructed at a different elevation than the current farm road and are there potential impacts to the frog pond, including runoff and bank stability? If the road is at the exiting elevation and the slope above it have to be laid back to meet the fairways, what distance will be required to drive the golf ball across the pond/channel?

The proposed project would impact 1.89 acres (20,038 linear feet) of creek channels. Staff is not able to identify the amount of linear feet to be recreated. The applicant submitted a figure of 23,070 linear to feet to be recreated, with 1570 linear feet in culverts. However, staff is unable to verify these numbers as these numbers were given as a total sum without individual tributary segment lengths. The Corps' February 16, 1999, letter requested that the applicant provide a map that clearly identifies the linear feet and reaches of tributaries that will be filled, and a map showing the linear feet and reaches of proposed re-created tributaries, including linear feet to be culverted on each. As of the date of this letter, the Corps has not received such map. Staff request that the applicant provide this map to all resource agencies, to aid in determining impacts to the site's tributaries.

As stated in our previous correspondence, staff is concerned about the long-term success and permanence of creek functions when creeks are "re-created" on top of engineered fill. The previous materials submitted were of examples that were of a much smaller scale and varied design, much less technically challenging, and do not demonstrate that the applicant's recreated tributaries will succeed. Also, staff inquiries on some of the projects revealed that the projects were "restoration" projects and not "re-creation". That is, it is our understanding that a new number of example projects were restoration of existing creeks, rather than creation of new creeks on top of engineered fill. The applicant also provided resumes on consultants who would be working on the proposed project and some information regarding White Gulch River in Montana. While the White Gulch River project used engineered fill, it is not appropriate to use it to predict the success of the applicant's creek re-creation since these two watersheds have distinctly different hydrologic regimes and geomorphology. In our January 4, 1999, letter staff requested that the applicant submit any supporting documents that they had concerning re-creation projects on engineered fill, including whether or not the project met performance criteria and permanently reestablished creek functions. No additional materials were submitted.

Our January 4, 1999, letter requested that the applicant submit cross sections of the proposed channel designs for the streambeds to be re-created. The applicant submitted several cross sections and a profile section for Moraga Creek. However, the drawings show the channel in post construction only. We are unable to determine how this differs from existing channel. Longitudinal sections do occur in the Draft Supplemental EIR for Moraga Creek. However, these drawings were based on the use of drop structures which are no longer being proposed. No drawings were submitted for the several northwest tributaries proposed for re-creation.

Staff is concerned about potential post-project changes in the amount of sediment being conveyed from tributaries to Brookside Creek. The Corps' February 16, 1999, letter also address the possibility of increased downcutting of Brookside Creek caused by the increase in sediment-carrying capacity of the water, once the tributaries are re-created and stabilized. The applicant also states that after project construction and the establishment of turf, sediment loading is expected to be less than under current conditions. Potential impacts to Brookside Creek need to be addressed.

We agree with the Corps' request for success criteria for performance of the re-created channels. We would also add that the applicant should base the re-created channel designs on the site's existing creeks and tributaries. In order for staff to determine whether the re-created channels have potential to succeed, staff would like the applicant to provide further detailed conceptual designs of the proposed re-created tributaries. The information should include the following and be based on pre and post construction/creation:

- Hydrologic conditions/analysis

- hydraulic model/analysis

-geomorphic analysis

- geotechnical stability

- sustainability (maintenance)

The applicant should also address:

- plans to tie the re-created channel into the existing channel, above and below the impacted channel.

- change in flow rates/flood conveyance

- changes to the channels depth, slope, and capacity

- changes to sediment input and transport

- potential impacts from unmitigated landslides above project site

- soil/hydrologic changes and potential impacts to Brookside Creek

Staff believes that the proposed riparian restoration and channel recreation will not fully compensate for temporal and long-term impacts to the present channels. The proposed re-created channels are mostly located within the development, and have minimum buffers from human disturbance. The value of the riparian habitat as nesting, breeding and foraging habitat will be permanently diminished as a result of the increase in adjacent land use.

Due to the nature of the project design, the potential beneficial uses of the re-created and existing creeks will be permanently reduced. All northwest channels are surrounded by housing or golf course. The applicant states in their submittal that the project has been adjusted to minimize crossings and culverts since the original application. However, the current golf course design requires 36 golf cart bridge crossings, 11 culverting of tributaries under fairways, and 23 areas where the course plays across the creeks and tributaries. While the applicant proposes to create a riparian corridor along these channels, the golf course maintenance to provide visual clearance, cart crossing and culverting will fragment this riparian corridor. These disturbances may inhibit the re-created channels from becoming a natural habitat with functions and values typical of a riparian creek corridor. It is also highly likely that golfers will enter this buffer zone to either play or retrieve their ball, leading to further impacts from disturbances, tramplings, compaction, etc. Simply charging a one-stroke penalty is not an adequate mitigation measure to prevent these impacts.

Staff requested a description of what land uses and structures would occur within the buffer zones. The applicant did not provide a response to this request. The applicant did submit a map which outlined the proposed buffer and discussed other environmental concerns which required the golf course and housing lots to be located close to the site's creeks. Staff concludes from the buffer map submitted that the applicant allows for the following items within a buffer zone: golf cart paths and bridge crossings, golf tee areas, play-over areas and fairways, emergency access roads, driveways, conservation easements, pedestrian, equestrian, and bicycle trails and Brookside Park. These activities will impact the buffer zone and the riparian corridor. Staff also requests that the applicant define what type of activities and structures will be allowed within the conservation easement.

Further impacts to the buffer zone are created by golf course play. Hole #6 requires an applicant to tee off and hit over 400 feet of buffer zone. Holes #11 and #16 require the golfer to tee off and drive over 200 feet of buffer zone. Hole #5 has a landing area (bunker?) within the buffer zone. Balls landing within the buffer zone will cause an impact as discussed above. It appears that Holes #2, #4, and #10 all have some tee areas within the buffer zone and depending on the tee spot, some require hitting over a tributary. Hole #9 tees off and plays over the multi-use trail. It is unclear to staff what the elevations of the tee greens will be. Are they going to be graded to an elevation higher than the tributaries/trails allowing for play over? Or will they be at the same elevation, which requires the riparian areas to be trimmed to allow for clear play? The applicant states that trimming will be strictly limited and that it will not break overstory canopy. Staff is concerned that to allow golf course play, impacts to both overstory and understory vegetation may be required. The applicant has stated that "no trees will be removed for golf play across creek." Staff believes that this statement is incorrect, as the entire golf course area will be graded and the majority of the tributaries will be recreated. Staff believes that the applicant will not be planting trees within the areas of play across creeks. The applicant should submit appropriately detailed information describing how play across creeks and across and into the buffer zone will impact vegetation there. In general, staff does not believe that the proposed buffer, which would be narrow, highly fragmented, and subject to regular disturbance from a variety of uses, is adequate to protect the buffered habitat and riparian ecosystem.

The applicant states that no repair work within Brookside Creek is proposed. However, the Corps' April 7, 1999 letter states that Brookside Creek must be stabilized using proven technology during project construction rather than as a series of armoring projects after development. Please submit the proposed restoration plan for staff to review. Staff would also like to point out that the applicant states in his submittal that tree planting does not require a permit from the Corps. However, if the planting or related grading has potential to impact waters of the State, the Board has jurisdiction over this activity.

The golf course fairways have been designed to act as detention basins. Sand filters will be constructed beneath fairways which are adjacent to the creek to filter surface flows before entering the creeks. It is unclear to staff whether these sand filters will be piped directly to discharge into the creek or simply allow subsurface lateral flow to occur. If it is piped directly, are there any potential impacts to the creeks, including increase flood peak/flow, downcutting, or need for stabilization of pipe outfall structures?

In our previous letter staff commented that it appears that Moraga Creek and its tributaries are being moved to facilitate the layout of the golf course, and not for geotechnical reasons. A 1700 foot section of channel will be impacted with approximately 20 feet of fill to create a building pad for the maintenance building. A tributary to Moraga Creek will be graded to accommodate Fairway 13, with up to 25 feet of fill and 10 feet of cut to build the greens. This same channel will be filled again at Fairway 11. Another small tributary to Moraga Creek will also be filed to create Fairways 11 and 13. We requested that the applicant explore restoring Moraga Creek in its present location, and redesign the golf course layout. The materials submitted state that the applicant is currently examining the golf course design to reduce impacts to Moraga Creek. The materials go on to state that it is unlikely that total avoidance is possible and that geotechnical concerns limit placement of the fairways. However, the September 4, 1998, submittal states that no geotechnical grading will occur along Moraga Creek where only golf fairways and open space are proposed (Chapter I.D. Geotechnical issues). In addition, the applicant has proposed to avoid filling Brookside Creek by performing upslope repairs which would reduce pressure on the banks bordering Brookside Creek and stabilize these banks. Is a similar design possible to address the newly identified concerns on Moraga Creek? Staff encourages the applicant to further explore the option for restoring Moraga Creek in place, especially in light of the fact that Moraga Creek is the location where the yellow-legged frog has been found on the project site.

The proposed project will impact 49 wetlands, of which 35 are seeps and 13 are seasonal wetlands. To compensate for these impacts, the applicant proposes to create a total of 26 wetlands.

Staff previously commented on concerns whether the proposed mitigation adequately compensates for the current site's wetlands function and values. The applicant states that they believe the wetlands proposed for construction will compensate for the impacts. However, the applicant did submit a proposal containing a few alternative sites which could replace previously proposed sites for wetland creation. This proposal was limited to an 11X17 map with color outlines. No further details of size, method of creation, or existing land conditions were provided.

The applicant's proposal also includes 7 seasonal wetlands which are located within or immediately adjacent to the golf course. These wetlands will have reduced habitat value by human disturbance and appear to be merely water features and hazards for the golf course. For example, wetland 26 is located between hole #9 tee area and fairway. It is highly likely that the less talented golfer will land a ball into this wetland. While the golfer may not retrieve the ball, eventually the wetland will need to be dredged to remove these wayward golf balls.

Staff have also commented on the 12 proposed created wetlands which are to be located within the conservation area. This open space area has a proposed pedestrian/equestrian trail (6' minimum width, non-paved improved surface) or pedestrian/equestrian/bicycle trail (6' minimum width, non-paved surface) that appear to either pass right next to or go through most of these wetlands. These trails will increase human disturbance impacts on these wetlands and may fragment those areas of created habitat. The applicant states that many of the wetlands are in high elevation, rugged areas with steep grades and that trail use in these areas is expected to be very infrequent. However, special open space destination and interpretive areas being proposed uphill of the quarry wetlands. This area will require minor grading and include tree plantings, benches, and areas for picnicking. Therefore, it appears that there may be significant impacts due to trail placement adjacent to or crossing the proposed mitigation wetlands. Staff is also concerned about placing wetlands in high elevations with steep grades. Will the watershed area provide enough water for the wetlands to be functional?

In addition, East Bay Regional Park District's letter, dated December 8, 1998, to the City of Orinda states that multi-use trails within the regional open space should be fire road standards 10'-12' to allow maintenance, patrol, emergency vehicle access. These trails should be unpaved dirt surface with a 1-3% outslope for a more natural drainage. These standards are almost double the width of the proposed trails. Staff recommends that the applicant relocate the paths away from the mitigation wetlands and submit a hydrology or other appropriate report, supported by data collected at the site, which demonstrates that there is sufficient water to support the mitigation wetlands.

Staff is also concerned about the proposed re-creation of seep wetlands. The applicant proposes to re-create seeps with the water coming from the keyway subsurface drains. We concur with the Corps' statement that they remain unconvinced of the reliability of the proposed seep designs. Staff is concerned that the applicant will not be able to determine the size of seep which might be created. The applicant is only proposing to create 6 seep areas, when 35 seep areas will be filled. To compensate for lost seeps, we expect the applicant to create 2-3 times the number of seeps to compensate for the loss. This small number of seeps not compensate for the large number to be filled, especially since they will occur in areas which have been graded and will rely on a dewatering system which could fail. Materials submitted state that if a subdrain system is extensive, it may also be fitted with a series of cleanout risers, so that the integrity of the collector pipes can be verified at a late date. Does the applicant plan to use cleanout risers? How and will these subsurface drains be maintained? What will happen if a drain clogs or collapses, given that these drains may be on private lots?

In the response to our seep questions, the applicant referenced another project, Windemere, which is currently being considered by the Board. The applicant states that they have had discussions with Windemere's consultant on how they plan to create their seeps. Please be aware that the Board reviews each project, potential impacts, and proposed mitigation on a case by case basis. While there may be some similarities between the two projects, there are also substantial differences, and it may not be appropriate for direct comparisons to be made between Gateway and Windemere. Windemere is located in a different watershed, has different site characteristics, as well as impacts. In addition, Windemere not receiving mitigation credit for seep creation. Instead, they are completing seep creation as a demonstration project. Windemere anticipates that over one-half of the seeps may not be successful.

Further, it appears that the applicant is proposing to count storm water quality mitigation required by the project's CEQA documents as mitigation for the fill of jurisdictional wetlands. This would violate Regional Board Resolution 94-102. Board Resolution 94-102 prohibits the use of storm water treatment wetlands as mitigation for impacts to jurisdictional waters. Your submittal of February 5,1999, states that "some of the wetland mitigation sites... are proposed as detention basins" which would be used solely for the control of flows, or water quantity, rather than pollutants, or water quality. However, this statement appears to be in error.

As mitigation for impacts to water quality resulting from the proposed project, the December 1998 Final SEIR for the project cites the mitigation measures required in the 1992 Final EIR, 1994 Final EIR Addendum, and 1994 Mitigation Monitoring and Reporting Plan (MMRP), as excerpted below:

Impact E-4: "Erosion due to longer flow duration" (FSEIR p. 164)

Mitigation E-4a: "Design, construct and maintain [four] detention basins to mitigate downstream effects of longer duration, higher peak flows" (FSEIR p. 164)

Impact E-6: "Water quality degradation" (FSEIR, p. 164)

Mitigation E-6a: "Design and construct the project such that road runoff will be carried in grass-lined swales to on-site ponds for infiltration. At some locations, ponds must provide biofiltration, physical filtration, settling of absorbed contaminants, and nutrient and metal removal by vegetation to prevent degradation of groundwater" (MMRP, p.50)

Mitigation E-6c: "Design and construct detention basins (see mitigation E-1b/1c) such that the bottom of the detention basins allows settling of pollutants" (MMRP, p.50)

Mitigation E-6h: "Design and maintain detention basins according to best management practices (BMPs) as they are established and adopted by Contra Costa County and/or other applicable public agencies. Evaluate the use of wet detention basins, which consist of a permanent water pool and a vegetated shallow zone that can serve as a biological filter to remove pollutants from stormwater" (MMRP P. 51)

Mitigation E-6i: "The detention ponds shall be grassed to aid in the filtering [of] pollutants, and scraped periodically to remove sediment buildup and enhance percolation. Baffles and flow retarders shall be installed to increase the amount of time that stormwater remains in the basins prior to discharge to allow for more settling and grass filtering of pollutants. The maintenance of detention facilities shall be scheduled to ensure that hazardous concentrations of sediments and vegetation are not created..." (MMRP, p. 52)

Therefore, based on the project's FSEIR and previous documents cited by the FSEIR, it seems clear that the proposed detention basins will be used to mitigate impacts to water quality. Pursuant to Board Resolution 94-102, such waters therefore cannot be counted as mitigation for impacts to jurisdictional waters.

It is unclear which waters on-site will be functioning as detention basins. The FSEIR requires a minimum of four detention basins (i.e. one in each of the project's drainage sub-basins)(FSEIR mitigation measures E-1b, E-1c, and E-6c through E-6i, p.164, and FSEIR discussion p.165). Additionally, the FSEIR states that the FDP "...envisions the use of golf course 'lagoons' for storm water detention, along Fairways 6 and 7 in Parcel T" (FSEIR, p.165-6). Finally according to the FSEIR, a wetland mitigation area in Parcel T would be used to store runoff. Presumably, this is wetland 19, the sole mitigation parcel located within Parcel T.

The applicant's submittal of February 5, 1999, states that the FSEIR's discussion of the use of wetlands in Parcel T is in error, and that under the current plan only three wetlands areas would be used for mitigation -- wetlands 1, 8, and 9. However, the next sentence states that "sites 2, 27, and 32 are required for detention basins under the revised plan." In addition, based on earlier submittals, including the October 1998 revision of the "Gateway Valley Final Development Plan," we had understood that six mitigation wetlands -- 1, 2, 8, 9, 27, and 32 -- were proposed to be used for storm water detention.

The February 5, 1999, submittal also includes information on drainage for parcels A, B, and H, and states that "...three created drainages within the quarry site will be bounded by vegetation and will serve to reduce any pollutant loading to the downstream sources" (p.3). Based on the applicant's "Wetlands, Waters of the U.S., and Riparian Mitigation Map," dated August 1998, it appears that these drainages are proposed to be used as mitigation as "Restored/Created Wildlife Habitat". The creeks themselves are shown as "realigned [jurisdictional] Waters of the U.S." Pursuant to Resolution 94-102, jurisdictional waters may not be used as storm water quality treatment controls, and separate controls should be proposed upstream of the creeks, within parcels A, B and H. Also it is unclear whether these three reconstructed/realigned creeks are proposed as mitigation for impacts to jurisdictional waters. As noted above, such mitigation could not also be used as a treatment control for storm water quality.

In order to resolve the confusion with respect to which proposed mitigation wetlands will be used for stormwater quality treatment controls, please submit an explanation of what mitigation wetlands/waters are proposed for detention and for use as storm water treatment controls, how this addresses the mitigation requirements in the project's CEQA documents, and why three areas are now adequate to achieve the detention that was previously spread over the much larger area of six areas. Please include in your submittal the area of each of the six individual mitigation areas, as well as of any other areas proposed for detention, the detention volume of the facilities proposed for detention, and the required detention volume for each sub-watershed.

Additionally, please submit the name(s) and contact information of flood control agency and City of Orinda staff responsible for approving the detention basins. Please be aware that removal of sediment to increase peak flow or water quality detention in wetland mitigation sites (i.e., in sites other than designated detention basins) may be prohibited as a part of any Board order for the site.

Please also submit a discussion, map, etc. of any proposed golf course lagoons or proposed surface water bodies that would be used to store water for use as irrigation on the golf course. Presumably, no such bodies have been proposed for use as mitigation for impacts to jurisdictional waters. It is our understanding that the applicant proposes to use treated, potable water from the Easy Bay Municipal Utilities District (EBMUD) for golf course irrigation. As we discussed in our meeting with you of February 23, 1999, such water would need to be dechlorinated prior to discharge. EBMUD and other water purveyors have prepared methodologies for dechlorinating chloramine-treated water, and it may be appropriate to incorporate one of these into project plans.

Staff visited the Garaventa Site, in Antioch, on April 30, 1999. The applicant is considering this site as potential off-site mitigation for project impacts which can not be mitigated on-site. We have not received a specific proposal for the use of this site. When considering off-site mitigation, staff recommends applicants seek to identify a site which is as close as possible to the project site (preferably in the same watershed) and contains similar wetlands and water features.

The applicant has provided details of the proposed Community Facility District (CFD) funded by a Mello Roos assessment. Staff went back and reviewed the Environmental Management Program (EMP) and funding which was submitted on September 2, 1998, and again concludes that the CFD appears to be inadequate as financial assurance that impacts to waters of the United States will be successfully mitigated and achieve predetermined success criteria.

After reviewing the submitted EMP, staff concludes that the applicant will enter into a Subdivision Improvement Agreement the City of Orinda and post a performance bond with the City for these improvements. The applicant will be responsible for on-going maintenance and monitoring, until these improvements are transferred to the Community Facilities District (CFD). The City of Orinda will oversee the CFD and will be funded by authority granted under the Mello Roos Act. Ownership of all natural open space lands, wetlands, and riparian areas will be transferred to the CFD. The CFD will be responsible for long-term maintenance in all open space areas (exclusive of the residential lots and golf course). A budget detailing annual operation funds for the first fiscal year was included.

While the CFD assures that the City will have funding for maintaining the site's improvements, it does not assure that mitigation for waterbodies impacts will occur. It is not clear when the CFD will take ownership of the open space, and if this will occur during the first 10 years of monitoring. In addition it is not clear to staff if the Subdivision Improvement Agreement will have jurisdictional mitigation concerns attached to it. Also, the City of Orinda holds this bond and Resource Agencies will not have a say in how it is spent. The financial assurance should be specific as to the length of time, parties involved, condition and criteria that must be met, and who will have the authority to determine when and how funds would be distributed. The applicant and not the potential homeowners, is responsible for assuring mitigation is successful. The preliminary budget for the CFD does not provide for funding if the mitigation fails. The monetary value should be sufficient to cover the expense of ongoing maintenance and monitoring of the mitigation plan, in addition to the costs that would be incurred in the event the proposed reconstruction/mitigation fails or is unsuccessful, including the purchase of additional off-site acreage. Staff is also concerned that the CFD, which will be funded by homeowners, will not have the ability or desire to maintain the several wetlands and creeks/tributaries which occur within the golf course. Homeownership does not include a golf club membership. If the City of Orinda accepts deed to the open space areas prior to the mitigation meeting the success criteria, they will become financially responsible for the mitigation. If this is the case, the City will be named in the Board Order as a responsible party. Please submit a schedule of when the City of Orinda/CFD will take possession of open-space areas.

The applicant is not proposing the use of grazing within mitigation sites. However, the applicant added the statement that "any open space areas that are transferred to third parties as conservation easements may include fuel management techniques in their management of the land." Many of the proposed mitigation sites are within open space areas. A condition of project approval may include a prohibition on grazing or the preparation of a range management plan.

The Board has previously commented on the project's potential impacts to water quality and beneficial uses of waters of the State resulting from increases in pollutants in storm water runoff and changes to runoff volume and the runoff hydrograph during construction and once the project is complete. Specific comments have been made in our letters of: May 8, 1998, commenting on the project's draft Supplemental Environmental Impact Report (SEIR); January 4, 1999; and February 4, 1999; and in our meeting of January 19, 1999, with the applicant's representatives. While some information has been produced by the City of Orinda as a part of the CEQA process or submitted by the applicant in response to our comments, the materials submitted to date lack sufficient detail for Board staff to determine whether our comments and potential impacts have been addressed.

As we noted in the correspondence and meeting referenced above, we are concerned that the project may have unmitigated impacts to beneficial uses of waters of the State resulting from changes in water quality occurring during construction and once the project is complete. Additionally, impacts may result from increased runoff volume and changes in the runoff hydrograph during construction and when the project is complete.

As a part of its review of applications for water quality certification, the Board considers potential impacts to water quality and the related beneficial uses of waters of the State and proposed mitigation for those impacts.

In order to understand the project's impacts and proposed mitigation measures and to ensure that the mitigation measures would be designed and function effectively over time, we suggested that you submit a storm water management plan (SWMP), a chemical application and management plan (CHAMP) for the proposed golf course, and a storm water pollution prevention plan (SWPPP). The SWPPP would address construction-stage impacts and mitigation measures, while the SWMP would focus on post-construction/permanent impacts and mitigation measures. The CHAMP would address the potential impacts resulting from the operation and maintenance of the golf course. The information in these documents is also required by the FSEIR as two documents: a SWPPP that incorporates both construction-stage and post-construction (i.e. SWMP) issues; and an Integrated Golf Course Management Plan (IGCMP) that would be similar to or the same as a CHAMP.

To date, we have received a partial SWPPP that addresses some construction-stage impacts. Your submittal of February 5, 1999, included some information on post-construction treatment controls and the use of detention basins for water quality treatment and wetland mitigation. However, this information is general, not site-specific, and lacks the detail necessary for Board staff to determine whether such measures would effectively mitigate the project's expected impacts. As we stated in our letter of February 4, 1999, the use of appropriately designed, operated and maintained storm water treatment controls could form a key part of the project's storm water management plan.

As a note, oil/grit interceptors are proposed for the project's parking lots. However, experience has shown that such devices are typically not maintained, or are maintained at a rate insufficient for them to function as mitigation for impacts to storm water quality. Board staff would support design measures, such as replacing impervious surfaces with crushed aggregate or other pervious surfaces and the use of landscape-based treatment controls, such as grassy swales, biofilters, etc., to mitigate the impacts of polluted runoff from parking lots.

In order to allow us to determine whether storm water quality impacts have been mitigated, please submit a conceptual or final plan for both construction and post-construction project design measures, treatment controls, and other best management practices. The plan should include a map, key, and associated narrative showing and discussing the project's drainage infrastructure, contributing watersheds -- including impervious surfaces such as roads, parking lots, houses, and other structures, and the location or proposed locations of the specific controls planned for the project. It may be appropriate to submit smaller, more detailed maps of specific areas of the project, such as the project's parking lots. Please also submit typical treatment control designs, including inlet and outlet designs, estimated performance information including residence time for flow and treatment efficiency, and all other necessary information (e.g. number of spaces of parking in each lot, road sizing, etc.) as appropriate.

The proposed project will likely increase the peak flows and duration of flows as compared to the present state. This has the potential to impact beneficial uses of waters of the State by effects including increased bank erosion and bed downcutting, and potentially requiring future stabilization or hardening of streams in order to protect structures, golf course holes, and other improvements located adjacent to creeks and other jurisdictional waters.

Based on the information provided in the FSEIR, it appears that the project's proposed detention basins would be designed to detain the 100-year peak flow, and not the smaller, more frequent flows that can be great contributors to changes in sediment transport, bank instability, etc. However, the FSEIR also states that the detention basins must be designed, constructed, and maintained to mitigate downstream effects of longer duration, higher peak flows (p.164). Presumably, this would include both the 100-year peak flow and the more frequent flows discussed above. Please submit information on the project's impacts to storm water quantity that shows what effect the project will have for both high and low-return period storms, what mitigation measures have been designed into the project to mitigate those impacts, quantitative information on the expected performance of those measures and all other necessary information, as appropriate.

We believe the project, as proposed, will have more than minimal and cumulative impacts to waters of the U.S. Other alternatives to achieve the project purposes and additional mitigation measures should be explored.

Please submit additional materials regarding this project, as indicated above, for staff review. So that everyone is working on the same project, we request that any information submitted also be copied to the Corps, EPA, CDF&G, USFWS, and the City of Orinda.

If you have any questions, please contact Elizabeth Morrison at (510) 622-2330 or Keith Lichten at (510) 622-2380.

Sincerely

Richard Whitsel

Chief, Wetlands Planning Office