October 1, 2020

Brian O’Neill, Coastal Planner

California Coastal Commission Central Coast District

725 Front Street, Suite 300

Santa Cruz, CA 95060

Subject: Requested actions to preserve and protect the Los Osos Groundwater Basin and dependent coastal resources

Dear Mr. O’Neill,

I’m writing on behalf of the Los Osos Sustainability Group (LOSG), a group of concerned property owners in Los Osos, to alert you to the unsustainable condition of the Los Osos Groundwater Basin (Basin) under current conditions. The most recent reports indicate seawater intrusion is still a major factor putting the Basin at continued risk and future failure. We therefore ask the Coastal Commission to take three immediate actions:

Requested Actions

1.      Direct the County not to approve any new or expanded development that will add new or expanded water service, and stop accepting any new development applications for all development in Los Osos until the County of San Luis Obispo is able to demonstrate with conclusive evidence that the Basin is capable of providing adequate water supply for current residents and businesses, as well already approved development. New and expanded development includes all water-using development inside and outside of the sewer service area, including but not limited to accessory dwelling units (ADUs), guesthouses, mobile homes, home additions, single- family homes, and multi-family homes. Such action may require that the Commission inform the County that no pending or future applications for water using development will be approved by the Commission. Our goal is to avoid individually appealing each project, but we are prepared to do so until and unless the Basin is shown conclusively to be sustainable.

2.      Require the County to use a standard of “conclusive evidence” to establish that the Basin is sustainable for current and any proposed new development before the Commission may consider approving any new development in Los Osos. To meet this standard, the County would be required to meet one or more clearly articulated and measurable physical objectives based on sufficient and objectively reliable well monitoring data collected over a sufficient time period in order to establish that seawater intrusion is reversed to prescribed locations and water levels are raised to prescribed elevations high enough basin-wide. The objective is to keep the Basin safe from seawater intrusion and all other harmful effects through adverse conditions such as droughts and climate change and ensure the Basin is capable of supplying sufficient water for existing and any new or expanded development.

“Conclusive evidence” does not include modeled sustainable yield estimates, vague and unenforceable provisions that allow discretion on the part of local decision makers to decide what constitutes sustainability or what justifies overriding sustainability objectives, nor does it include evidence that proposed new development has complied with a conservation retrofit to build program, such as the Title 19, 2:1 retrofit program currently being applied in Los Osos. The current retrofit to build program in Los Osos uses the conservation potential needed to sustain the current existing residential population and businesses as well as water- dependent natural communities (ESHA).

3.      Put the County on notice that it must fully implement and comply with Special Conditions 5 and 6 of the Los Osos Wastewater Project (LOWWP) Coastal Development Permit (CDP) before the County may begin accepting any new water-dependent development applications. Neither the County nor Coastal Commission staff has provided the LOSG with a copy of the “Annual Reports” we have formally requested. These reports are required by Special Condition 5(d) in order for the Coastal Commission and the public to determine the success or failure of LOWWP conservation, reuse, and monitoring programs [Special Conditions 5(a- c)]. The County Planning Department recently estimated that 160 to 350 AFY of conservation potential exists in Los Osos although Special Condition 5(b) was supposed to “help Basin residents to reduce...water use as much as possible...” The Planning Department provided the conservation potential estimate, however, not to support the sustainability of the Basin for current residents, but to justify more development via use of the Title 19 conservation retrofit program. The County is now allowing applications for water-using development within the wastewater service area, and it is allowing washers and possibly other water saving devices to be retrofitted within the sewer service area. These actions and policies violate Special Conditions 5 & 6, the Coastal Act (e.g., sections 30231 and 30254), Coastal Plan Policies (e.g., Public Works Policy 1 and Watershed Policies 1 and 2), and the Coastal Zone Land Use Ordinance (CZLUO) (e.g., Section 23.04.403).

Evidence the Basin is not sustainable under current conditions

As we explained in our letters to the County Planning Commission on June 26, July 8, and August 11, 2020 (attached), substantial evidence, primarily documents prepared for the Basin Management Committee (BMC), demonstrate that the Los Osos Basin is not sustainable under current conditions. We provide some of the evidence here.

The most recent chloride monitoring results and a graph of Water Level and Chloride Metric trends from spring 2020 show that seawater intrusion is advancing in lower aquifer Zones D and E. After showing signs of improvement in 2017 and 2018, the Chloride Metric, which the BMC uses as an indicator of seawater intrusion, has risen from 145 mg/l in fall of 2018, to 163 mg/l in fall of 2019, to about 180 mg/l in spring of 2020, indicating worsening conditions. (See attached file labeled “WL and CL Metrics, Spring 2020 Draft.”)

At a new monitoring well near the estuary, chloride levels in Zone E, the deep aquifer, rose from 1460 mg/l in fall of 2019 to 2190 mg/l in spring of 2020, indicating severe and worsening seawater intrusion conditions (See attached file labeled “WQ Monitoring LA wells Spring 2020”). Basin capacity is considered to be permanently lost when chloride levels reach 2500 mg/l of chlorides according to several Basin reports.

A November 2019 technical memorandum (TM) prepared for the Basin Management Committee (BMC) found seawater intrusion in Zone E to be moving inland at a northern location where it was not previously detected, indicating it could be moving into the Basin across a wider front. The 2019 TM entitled “Lower Aquifer nitrate concentrations trends review and LA11 seawater intrusion evaluation” warns that Zone E seawater intrusion can “upcone” into Zone D contaminating Zone D wells, and the Los Osos Groundwater Basin Plan (Basin Plan) states that the clay layer separating Zone D from Zone E may be “discontinuous” (See TM, p. 8; Basin Plan, p. 64). Thus, Zone E intrusion is not only threatening the largest aquifer (Zone E) but also Zone D, which currently supplies most of the community’s water supply.

The 2019 Annual Monitoring Report prepared for the BMC provides “a generalized plan view interpretation” of the Zone E seawater intrusion front because the current Basin monitoring program has an insufficient number of monitoring sites to accurately map the intrusion front. The “generalized...interpretation” shows the Zone E front extending under several Zone D community supply wells to a point just west of the commercial area where several major purveyor supply wells have formed a very large pumping depression in the lower aquifers.

(See the 2019 Annual Monitoring Report, e.g., pp. 49, 54-55, Figures 11 and 14, and Appendix D, Figure D6.

The Annual Monitoring Reports, November 2019 TM, and Basin Plan can be found at

https://www.slocounty.ca.gov/Departments/Public- Works/Committees-Programs/Los-Osos-Basin-Management-Committee-(BMC).aspx

Seawater is pulled into a basin by low water pressures caused by pumping and low water levels. The 2019 Report confirms that water levels along the seawater intrusion front and throughout much of the Basin’s two lower aquifers west of Los Osos Creek remained at or below sea level for the year. In the large pumping depression near the commercial area, water levels remained between about 8 feet below to 32 feet below mean sea level in 2019.

The Basin Plan sets a target of 8 feet above mean sea level for water levels to stop and reverse seawater intrusion. One Basin expert recommends that the target be set at 12 feet above mean sea level to protect Zone E. The Basin Plan states that water levels must be 17 feet above mean sea level in Zone E, the deepest aquifer, to stop seawater intrusion (Basin Plan, p. 84). Thus, much of the Basin is vulnerable to seawater intrusion, which has shown an alarming increase according to recent data. It should be noted that water levels relative to mean sea level are 2.8 feet below the levels shown on water level contour maps in Annual Monitoring Reports (e.g., Figure 14) because levels are reported in NAVD88, which has a “0” value 2.8 feet above mean sea level.

All Annual Monitoring Reports since 2016 have recommended more conservation to improve seawater intrusion conditions. Accordingly, the conservation program required by the Coastal Commission in 2010 for the Los Osos Wastewater Project (LOWWP CDP Special Condition 5b) and the complementary Basin Plan conservation programs should be maximized immediately. (See 2019 Annual Monitoring Report, Table ES-2.)

The County of San Luis Obispo’s position on further development in Los Osos

Despite the discouraging recent data, the County of San Luis Obispo seems intent on pushing ahead with more development in Los Osos. The County Planning Commission reviewed the Estero Plan Update (Los Osos Community Plan—LOCP) on July 9th and August 13th. At the second meeting, the Planning Commission did not modify the proposed language in section “7.3 Communitywide Standards,” which is supposed to ensure approved new development has a sustainable water supply.

(See file labeled “Pl Comm 8.13.20 Attchmt 5, Chp. 7 showing LOCP, pp. 7-1 through 7-3)

The latest proposed LOCP language and revisions to the County Growth Management Ordinance (GMO) recommended by the Planning Commission would exempt accessory dwelling units (ADUs), affordable housing, and commercial-to-residential conversions from growth rate limits and criteria for determining that the new development has a sustainable water supply, so long as the development meets a Title 19, 2:1 retrofit requirement. The proposed language would also allow the Board of Supervisors (Board) to remove the Title 19 requirement based on a vague and unenforceable condition (i.e., the “new development can be accommodated by the sustainable yield of the Los Osos Groundwater Basin without causing seawater intrusion, as identified in the Basin Plan and annual monitoring reports”).

(See our August 25, 2015, August 11, 2010 letters for explanations of why this language can result in harm to the Basin and resources.)

The proposed LOCP revisions would also allow the Board of Supervisors to approve “Discretionary Land Use Permits” with a 1:1 conservation offset even “...if the groundwater basin may not accommodate increased groundwater extraction...” and the language exempts all development, including development within the sewer service area, from growth rate and other standards, if a permit application is submitted prior to final approval of the LOCP by the Board.

(See attached file labeled “Pl Comm 8.13.20 Attchmt 5, Chp. 7.)

Recently obtained documents show the County is allowing Title 19 homes and businesses within the sewer service area to be retrofitted to meet retrofit requirements for new development. We also learned that the County has accepted many more permit applications for water-using development pending and/or being approved inside and outside the sewer service area.

(See attached email file dated January 20, 2020, and file labeled “Los Osos Building Permits sorted”).

The proposed LOCP language and the County’s continued processing of development applications in Los Osos are inconsistent with Coastal Plan Policies (e.g., Public Works 1 and Watershed Policies 1 and 2) and the Coastal Zone Land Use Ordinance (CZLUO) (e.g., Section 23.04.403) because there is no evidence that sustainable water supply exists to support current development without permanently harming the Basin, existing development, and water-dependent ESHA. The proposed language and County actions also violate Special Conditions 5 and 6 of the Los Osos Wastewater Project (LOWWP) CDP because they do not ensure groundwater flows to ESHA, maximize conservation for current development, and avoid unsustainable development.

Approving more development in reliance on Title 19 and conservation offsets will deprive the current and future Los Osos residents from having an adequate and reliable water supply

A Title 19, 2:1 uses conservation potential at a rate that is half as efficient as a conservation program for current development. For instance, the Planning and Building Department’s estimate that 160 AFY to 350 AFY of water conservation potential remainsz in Los Osos would at best provide only 80 AFY to 175 AFY of water use reduction for new development because the new development increases demand by at least half of what it offsets. As we have already stated, given the current seawater intrusion conditions, all of this potential water conservation potential will be needed just to achieve a sustainable Basin for current development. (See our attached August 11 letter for more detail on why Title 19 does not assure a sustainable water supply for approved development and how it can undermine opportunities for a sustainable Basin.) None of the potential water conservation should be set aside for new development at the expense of the water security and long-term sustainability of existing residents.

Why the Basin Plan and management actions cannot currently provide conclusive evidence of a sustainable water supply for the existing or additional population

In our letters dated December 11, 2019, June 26, 2020, and July 8, 2010 to the County Planning Department (attached), we provide and discuss substantial evidence that the current monitoring program cannot and does not track seawater intrusion in the deep aquifer, Zone E, and that Zone E intrusion threatens Basin sustainability. One reason is that when last measured in 2013, seawater intrusion in Zone E had already reached the large pumping depression near the commercial area.

In our letters, we also cite credible evidence that shows the current Basin metrics are not reliable because of variability and bias issues acknowledged in the Annual Monitoring Reports. We further provide substantial evidence that Basin modeling overstates the true sustainable yield of the Basin and could result in new development that further overdrafts the Basin because modeling does not account for 13% less rainfall over 15 years or the ineffectiveness of Broderson leach fields. In two of our attached letters we cite the findings of the CSU Monterey Bay Watershed Institute indicating that the movement of water (e.g., from Broderson leach fields) through the regional aquitard will take 171 years. Water discharged at the Broderson site must move through the 50 feet thick clay layer (aquitard) separating the upper and lower aquifers before it can influence seawater intrusion in the lower aquifers.

Modeling also assumes the lower aquifers are continuous from the estuary on the west side of the community to Los Osos Creek on the east side. However, a recent dry test well on the east side of the Basin shows the assumption is not accurate. The Basin Plan and monitoring reports further acknowledge 5% of uncertainty in modeling because about half of the total Basin water use (production) must be estimated.

(See 2019 Annual Monitoring Report, p. 37.)

Reduced rainfall and non-operation of Broderson leach fields alone could reduce the actual sustainable yield of the Basin to substantially below modeled “sustainable yield” estimates, even with the 20% buffer that the Basin Plan sets as a goal (i.e., a Yield Metric Target of 80 or 80% of estimated “sustainable yield”). The fact that seawater intrusion continues to move into the Basin and water levels along the front are still well below the target level of 8’ above msl, despite Basin Yield Metric values having been below the target of 80 for over four years, also suggests the model is inaccurate.

The Coastal Commission’s current position on development in Los Osos

Since 2010, the Coastal Commission has allowed development outside of the sewer service area that uses water from the Basin if that development complies with a Title 19, 2:1 retrofit offset requirement. We recently learned that Coastal Commission staff are also allowing accessory dwelling units (ADUs) to be approved within the sewer service area (see attached email file dated July 21, 2020). Because the Planning Department has indicated in the LOCP and related documents that all building in Los Osos is subject to a Title 19 requirement and the County is allowing the retrofitting of homes and businesses within the sewer service area, Coastal Commission staff may also be allowing retrofits within the sewer service area.

We received two lists of building permits approved or pending final approval in Los Osos since 2010 from the Planning and Building Department in response to a records request. We also received a list of dwellings retrofitted. The building permit lists include permits for about 28 ADUs and guesthouses, about 44 single-family dwellings, and about 12 other structures that we were able to identify as likely being subject to Title 19 [see highlighted permits in attached file “LO Building Permits (highlighted)”]. Although all of the structures we highlight appear to be subject to Title 19, the list of retrofits we received is for about 27 single-family homes and one second-story residence. Many of the retrofit credits have come from the wastewater service area, and we noted that the washer retrofit credits required to offset a single-family home have been substantially reduced from what is stated in Title 19. We’ve submitted a records request to better understand how the County has been implementing Title 19 and will update the Coastal Commission when we receive the information.

see “Los Osos Building Permits (highlighted),” & “Los Osos Building Permits, 2010-Aug2020, & “Los Osos T19 Retrofits, 2010- Aug2020”

We ask you to stop all of the above practices and to inform the County that all building, including building that has met a Title 19 requirement, will stop and will not be approved by the Coastal Commission until the County can show with conclusive evidence that the Basin can support the present and any proposed additional development.

The approval of any development in Los Osos is inconsistent with the Coastal Act (e.g., sections 30231 and 30254), Coastal Plan Policies (e.g., Public Works Policy 1 and Watershed Policies 1 and 2), the Coastal Zone Land Use Ordinance (CZLUO) (e.g., Section 23.04.403), and Special Conditions 5 and 6 of the LOWWP CPD because approval of new development does not protect and preserve the Basin and ESHA or ensure sustainable urban growth within the coastal zone.

Why Coastal Commission staff’s position is inconsistent with Coastal Policies and other requirements

For the Coastal Commission staff to continue to support the use of Title 19 retrofits within the sewer service area for new development, staff must be required to establish that the Basin can support the development, that the Title 19 program ensures a sustainable water supply for the development, and that the program will not use conservation potential needed by current development to achieve a sustainable Basin. We do not believe the current data and modeling support continued development in Los Osos. Please respond to tell us if this is your position.

We specifically request that the Commission demonstrate how retrofit offsets and any development within the sewer service area, including ADU’s, are consistent with Special Conditions 5 and 6 of the LOWWP CDP. Special Condition 5(b) requires the County to use a $5 million allocation “...to help Basin residents to reduce their potable water use as much as possible through measures including but not limited to retrofit and installation of low water use fixtures and grey water systems.” This requirement includes washer retrofits and all other retrofits the County is suggesting can be used for Title 19 compliance. (See file labeled “Pl Comm 8.13.20 Attchmt 8 attached, e.g., p. 6). Based on information provided in the 2019 Annual Monitoring Report prepared for the BMC, several million of the $5 million allocation for conservation required by Special Condition 5(b) is still available. (See 2019 Annual Monitoring Report, p. 81.) It seems to us that the intent of Special Condition (5)(b) was not to allow new development to use the conservation potential to support new or expanded development.

Further, Special Condition 6 requires that amendments to the Estero Area Plan “identify... sustainable buildout limits... and ...mechanisms to stay within such limits, based on conclusive evidence... that an adequate water supply is available to support development of such properties without adverse impacts to ground and surface waters...” (Emphasis added.) This has not been done.

Why “conclusive evidence” of an adequate water supply is the appropriate standard for approval of all development in Los Osos

Although Special Condition 6, as currently worded, prohibits only the approval of “undeveloped properties” within the sewer service area, the LOCP applies to all development within Los Osos and the intent of Special Conditions 6 (like Special Condition 5) is clearly to ensure the sustainability of the Los Osos Basin and dependent ESHA. That intent can only be achieved if the standard is applied to all development using water from the Los Osos Basin. Unsustainable new development outside the wastewater service area poses just as great a threat to the Basin as unsustainable development within the sewer service area and unsustainable development on developed properties poses just as great a threat as on undeveloped properties. To protect and preserve the Basin and ESHA, approval of all new development must be conditioned on “conclusive evidence” of sustainable water supply.

Conclusion

The “conclusive evidence” standard is both reasonable and necessary for approval of all new development in Los Osos, and we request that Commission staff support the standard and inform the County that the Commission will require the standard prior to approval of any further development. The standard recognizes the uncertainties in modeling, the continuing threats that seawater intrusion and the LOWWP pose to the Basin, and the Basin’s vital importance as an irreplaceable water source, essential to the health and survival of the community and high-value environmental resources.

Since the County will not and cannot currently provide conclusive evidence of a sustainable water supply for the current or additional development, all water-using new development must be stopped and conservation measures maximized to protect the Basin for existing development and Basin-dependent ESHA.

Again we ask that you take immediate action to implement our three requests above and respond to tell us how the Coastal Commission will proceed.

Sincerely,

Patrick McGibney

Los Osos Sustainability Group (LOSG)