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HomeMy WebLinkAbout11/14/1989, 6 - COUNCIL REQUEST FOR WATER INFORMATION: ALLOCATION OF NEW SOURCES; RETROFIT RATIO; DEMAND FROM EXEMP J r MEETING TATE 411111111110% aty of san Luis oBispo Nov. 140 19,99 i COUNCIL ACaENOA DEPORT nW NUMBER: 6 FROM: Randy Rossi, Interim Community Development Director, BY: Glen Matteson, Associate Planner SUBJECT: Council request for water information: allocation of new sources; retrofit ratio; demand from exempt projects. CAO RECOMMENDATION Review information and direct staff as desired. DISCUSSION The council has asked for information on the subject topics, which staff is presenting. SIGNIFICANT IICPACTS Review of this information will have no impacts. . CONSEQUENCES OF NOT TAKING ACTION Any action which might follow from council direction in response to this information would probably affect water use and development activity no sooner than July 1990, since water limits for this year have been firmly (but not irreversibly) set by previous ordinance actions. Council reevaluation of these items is timely but not urgent. '"111111#X§1 city of San Luis OBISPO 11111196 COUNCIL AGENDA REPORT SITUATION On September 5, the council took steps to change the Water Allocation Regulations so new sources could be partially allocated to development only when they can actually deliver water. At that time, the council asked for information on the subject items, which Community Development staff is providing. Council also asked for information on how reliability of groundwater is demonstrated. At that hearing, the Utilities Director explained the methods and noted cost ranges for evaluating groundwater reliability. Information on San Luis Obispo's groundwater basin is forthcoming from the state Department of Water Resources. The council also asked for information on the legality of banning/regulating private wells, forthcoming from the City Attorney. RESPONSE A. Allocation of new sources When the council amended the general plan Water Management Element and adopted the Water Allocation Regulations in 1988, the council determined that it would be acceptable for the city's normal water use to exceed safe yield by a certain amount then and in the near future, but that one-half of the added safe yield from new water sources should go to getting normal use and safe yield in balance and half should be allocated to new demand (development projects) . Now that the community has experienced the consequences of exceeding safe yield, there is renewed interest in getting normal water use and safe yield back into balance sooner than the current rules would allow. Normal water use, including projects approved or under construction and projects for which water was reserved because they were under planning review by March 15, 1989, is about seven percent above safe yield (8,380 vs. 7,810 acre-feet annually) . Under the current half-and-half rule, the city would need to add 1, 140 acre-feet to get back in balance, which would be reached when normal use and safe yield are both 8,950 acre-feet. If the city committed all additional yield to getting back in balance, 570 acre-feet would be needed, and the balance would be reached at 8, 380 acre-feet. While the city has investigated some thirty wells, yields from only four have been credited toward safe yield. Additional yields may be credited in the next few years as more wells are brought on line and groundwater reliability is demonstrated. If I reliable groundwater supplies do not provide the 570 to 1, 140 i acre-feet needed to get back in balance, the balance would have to await one of the proposed surface water sources, such as j���� City of San IDIS OBISPO Eft COUNCIL AGENOA REPORT coastal streams diversion, Salinas Reservoir expansion, Nacimiento Reservoir conduit, or the Coastal Branch of the State Water Project, all several years away. Under the maximum one- percent growth rate of the adopted band Use Element, the added 570 acre-feet of water demand would occur over about seven years (the Water Allocation Regulations, now allowing two-percent growth, would have to be amended to be consistent with the one- percent growth rate) . The decision to exceed safe yield is a judgment based on an assessment of .risks to providing an acceptable level of service. The most reliable water service is provided when normal water use is less than or equal to safe yield. If additional water sources cannot keep pace with development, development must be limited to avoid exceeding safe yield. If the city was to base its water allocations solely on the relationship between normal use and safe yield, the amount of rainfall this winter would not affect allocations to development. This is because rainfall in one year does not affect safe yield, which is calculated based on historical rainfall and runoff patterns. B. Retrofit ratio The Water Allocation Regulations say that if the expected water use of a project is offset at a ratio of two to one, the project does not need a water allocation, and may be built regardless of water limits. As an example, if a builder proposes a house. needing 0.37 acre-feet and retrofits plumbing fixtures in existing development to save 0.74 acre-feet, the house may be built without a water allocation. The council chose the .2: 1 ratio thinking that, even if the estimates of water savings were off by a significant percentage, there would be no net increase in water use, and probably a net reduction in water use. The number of retrofitted units to date (about 200, including houses, apartments, and motel rooms) and the time since completion of retrofitting (a few days to a couple of months) are not sufficient to assess the accuracy of our estimates. We will evaluate our estimates after we have a larger sample of retrofitted units and a longer water-use history during normal (non-rationing) ;times. Our current retrofit savings estimates are based in part on Morro Bay's five years' experience, including that city's recent adjustments to reflect their earlier over estimation of savings. Our current offset ratio, in conjunction with such factors as retrofit costs and perceptions of future water availability, has resulted in retrofits being done in order to build individual new houses and add-on units, but not major water users like motels or �3 11111lo1011p ig city of San LUIS OBISp0 WMIGeCOUNULAGENOA REPORT ft multiunit residential projects. Changing the retrofit ratio would not change the amount of water available to customers or the relationship between normal water use and safe yield, in the immediate future. If the water situation remains tight for several years, a changed ratio could affect water availability in the longer term, say three to five year from now, if a lot of retrofits are done. Looking at recent retrofit projects shows why this is so. In roughly the last six months, 200 units (houses, apartments, or motel rooms) have been retrofitted, resulting in about five acre-feet savings in annual water use. If the retrofit ratio had been three-to-one rather than two-to-one, another five acre-feet would be saved, on an annual basis --amounting to less than one one-thousandth of normal citywide water use. At some point, increasing the offset ratio would be self- defeating, since the cost of the retrofits would not be justified by the benefits of building, so fewer offset projects would be proposed. Staff does not know where this break-point is, but suspects it is somewhere between 2:1 and 5:1, for the city as a whole. Certainly, as an example, the acceptable ratio is much higher for someone holding a $200,000 single-family lot than for someone wanting to do a $20,000 tenant improvement for a risky business venture like a new restaurant. The question of the proper offset ratio was raised most recently when staff noted in another report to the council that during a multiyear drought, for every acre-foot that normal water use exceeds safe yield, annual water use must be reduced about four acre-feet below normal levels to avoid running out. This four- to-one ratio does not necessarily lead to a four-to-one offset ratio being desirable. As noted above, unless many offsets are completed quickly (sooner than new sources are obtained) , the ratio will not make much difference in the short-term water situation. The steps that would make a big difference are (1) allocating water from new sources only when their reliability is demonstrated and they can actually deliver water (recently endorsed by the council) and (2) allocating all of added yield toward getting back in balance, proposed by staff and the Planning Commission. C. Exempt projects The attached table shows the numbers and types of exempt building applications received during the last year. Several types of exempt projects have no effect on water use: I remodels and tenant improvements where the basic use or level of activity does not change. Many of the exempt applications we account for are revisions to structural plans or things like ,11111►1III11IM111 crty of san Luis oaispo _MIGs COUNCIL AGENDA REPORT signs or grading, which involve no water use. Most permitted residential additions, staff believes, have a minor effect on water use, since the added household activities or members probably would have occurred whether or not the building was reconfigured to more comfortably accommodate them. Also, many residential floor area additions take the place of landscaping, resulting in about the same water use before and after. Some additions and garage conversions creating additional living space or separate dwelling units do accommodate additional people that would not otherwise live in the city, resulting in more water use than before the work. As options for new permitted construction are constrained, there will be added pressures for conversions and additions to be done without permit (illegally) . Such non-permitted projects cannot be accounted for through Community Development but their added water demand will show up in water use figures, and thereby influence future allocations. To some extent, permit applications which never lead to completed projects will offset actions without permits. Also, some actions reduce water use, though they are not individually accounted for. Conversion of a restaurant to a store is an example. When the council endorsed the Community Development Department's allocation procedures, it acknowledged that such occasional reductions would. help offset the exempt projects, and that trying to account for each exempt increase or each decrease was not warranted. Exempt commercial additions have a greater potential than residential additions to increase water use. They include any increase in floor area of 1,000 square-feet or 50 percent, whichever is greater. So far, there have been only a few exempt commercial additions, but more can be expected if options for new construction are constrained. of more concern than exempt projects in overall water accounting are the trends of more intensive use (such as more employees in an office or residents in a house) , that will increase water demand in ways beyond city control. The only way to gauge those effects will be to monitor water use over the years, making any necessary adjustments in normal use, or the water use factors we apply to estimate water demand from new development. Without any hard data on which to base an estimate, staff. thinks that exempt projects --as opposed to activities which are not even "projects" for purposes of water allocation-- might increase water use five to ten percent above that estimated for permitted projects which occur during a given time. I OTHER DEPARTMENT COMMENTS _. The Utilities Department concurs with this evaluation. / C i���Illl city of San Luis OBISpo emus COUNCIL AGENDA.DEPORT CITIZEN PARTICIPATION On September 20, 1989, the Planning Commission supported allocating 100 percent of new sources to regaining a balance between normal water use levels and safe yield (six to none voice vote, with one member absent) . RECOMMENDATION Review this information and give staff any desired direction. Changes to what we do now would require environmental review and separate public hearings to consider amendments to the general plan Water and Wastewater Management Element and to the Water Allocation Regulations. Staff favors: A. Allocating all new sources to regaining a balance between normal use and safe yield. B. Keeping the 2:1 retrofit ratio. C. Keeping the current categories of exempt projects. If the council is concerned about exempt projects, staff would suggest having only those nonresidential additions that are up to 1,000 square feet or 50 percent of existing floor area, whichever is less, be exempt. D. Effective July 1990 through June 1991, and following years, having water use increase a maximum one percent per year, regardless of the water situation, to be consistent with the adopted Land Use Element. gmD: wtrinf.wp I 1111111111pw fj cmy of san tins oBispo MiS COUNCIL AGENDA REPORT EXMOT pROJF=S September 1, 1988, through August 31, 1989 Type Number Percent Residential additions 93 9.6 Nonresidential additions 8 0.8 Remodels 53 5.4 Tenant Improvements or Replacements 68 7.0 (with no increase, or with water use accounted for by shell building allocation) Pools and spas 9 0.9 Other exempt applications (signs, 743 76.3 grading, revisions, etc. ) TOTAL 974 100.0 Source: City of S. L. O. Community Development Department gmD: wtrinf.wp I 0110