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Benton County Public Works Utilities – Cascade View Water Management Plan

Management Plan Background

As part of the Conditional Use Permit for the Cascade View Subdivision a Water Management Plan is required to be submitted to the Benton County Planning Department for their approval. This requirement for a Water Management Plan was a result of concerns from the Planning Department Staff, Oregon Water Resources and the citizens of the area regarding the long term adequacy of the groundwater reservoir to supply water for this area with continued development.

Though Cascade View Subdivision only represents about 7% of the total population within the area, and thus a small part of the total water usage, a plan addressing the Subdivision's water use was felt necessary to adequately protect the resource. The Cascade View Subdivision will serve as a model for the rest of the community in conserving water without damaging the quality of living.

Ultimately the Oregon State Water Resources Department (WRD) will control water usage at the subdivision directly through the Water Right Permitting and Certification process. The subdivision will have a water right which is junior to all other rights around it; including private wells constructed and put into use prior to the date the water right permit application was filed. The WRD will then restrict water use by the Subdivision to maintain water in senior user's wells.

As part of the WRD permit system, conditions of approval will include a maximum static water level drawdown, of 25 feet, that will signal water curtailment measures be implemented. The 25 feet of static drawdown must be measured in the pumping well or a nearby (close proximity) static water level measuring well. This water level is the water level within the well to which the water rises during times of no pumping and normal recharge and is intended to measure the impact on the aquifer and the aquifer's ability to recharge fully to it's previous level. Twenty-five feet is a very tight level of control yet allows for normal climatic cycles.

Purpose

The purpose of the water Management Plan is to provide a set of operating procedures, monitoring systems, action levels, and appropriate responses to adequately protect the groundwater resource to allow for sustained use of groundwater for the Subdivision and hence for the surrounding users. As long as the Cascade View Water Supply System does not overdraw its own resource the surrounding water user's resource will not generally be adversely affected. In some very rare instances the dynamic use of this system, even while not overdrawing the groundwater reservoir, may have temporary impacts on surrounding water users that must be addressed. These are to be handled by the extra-system connections allowed for in the Conditional Use Permit.

The Plan

The developer shall install an approved community water supply system with the capacity to serve a minimum equivalent of 60 single family households. The system shall be constructed at the developer's expense. It is intended that a County Service District be created in accordance with ORS 451 and ORS 198 for the purpose of managing and operating a domestic water system.

The developer shall operate, or contract with County to operate, and maintain the system until the system provides services for at least 25 customers. Ownership, management and operation of the entire system shall be transferred to the County Service District at the beginning of the County's fiscal year immediately following the connection of the 25th customer to the system. The District will operate in accordance with the Code for Operating District Water Systems.

This Water Management Plan is designed as a total systems approach to water management. It includes elements of control from the time of water withdrawal from the well, through use, to disposal. Using a total systems approach allows for the most water conservation with the least waste while maintaining high livability. The design of the water system itself and its quality assurance and quality control (QA/QC) are the first step in water conservation. This carries through the operation of the system, the monitoring of water use within the system and the conservation methods to be employed in the system. The conservation methods include both those instituted as normal operating procedures and restrictions, and those implemented in response to specific system needs for increased conservation, such as at times of sustained drought.

It is of primary importance that this Plan be updated periodically to take advantage of changes in technology and the increased knowledge gained about the system and the groundwater reservoir upon which it depends. This Plan will require the collection of significant data that has hitherto been unavailable regarding the response of this aquifer(s) to sustained pumping and yearly recharge. By updating this Plan, full advantage of the gain in knowledge can quickly be incorporated into the operation of the Water System. It is suggested that modifications to the Plan, if there are any, be submitted in an Annual Report to Benton County Public Works Department and the County Service District's governing body.; The Annual Report will contain all the operating and water level data collected and a summary of its interpretation.

Supply and Distribution Redundancy

The Cascade View Water Supply System is designed with redundancy built in. By constructing a looped system if repairs or new connections are required the water can be rerouted to all destinations with the least disruption to the users or loss of water during the repair process.

The system will also have redundancy in water supply with the use of two wells, Number 1 and Number 4. These two wells are adequate to meet even the anticipated peak demand for water. During times when repair of one of the system wells is required either well can sustain the water system, though Well Number 1 cannot sustain normal summertime usage for extended periods of time. Wells Number 2 and 3 are also available for use and can be readily plumbed to the system as a further backup to Wells Number 1 and 4.

Reduce Supply Impacts with Two Wells

The annual average water use was initially modeled with 500 gallons per day (GPD) use expected. Using a more realistic average of 450 GPD usage rate, as seen at the Vineyard Mountain System, the highest use month the rate is estimated to be 900 GPD and during the highest day between 900 and 1170 GPD. With a 30 gallon per minute (GPM) well (Well Number 4) and an 8 GPM well (Well Number 1) the system could sustain 60 homes during the peak month.

Well Number 4 can sustain 30 GPM but well efficiency drops off and therefore pumping costs will increase. Water conservation measures are expected to reduce the need to less than 30 GPM in practice. Well Number 1 can sustain 8 GPM during the summer drought period and probably more during the winter months. These two wells pumping at a combined rate of 38 GPM can easily sustain the system. Using two wells reduces the impact on the system and the groundwater reservoir.

Wells Number 2 and 3 can be used as back-up and during times when repairs are required in the summer months. Either of the primary wells (Numbers 1 and 4) along with the back-up wells can sustain the system under water rationing conditions until the repairs are completed. Since failures during a high use period are more likely than during low use times, water rationing requirements are outlined in the operating and conservation sections of this plan.

During winter months Well Number 4 can sustain the system since use will be down to about 250 GPD or a sustained rate of only 8.3 GPM. During winter months Well Number 1 could sustain the system indefinitely while Well Number 4 was under repair. Long term planned maintenance of the system wells should be planned for winter months. There for all weather access must be maintained to all four well sites to allow for winter well maintenance.

Following is a table outlining the operating parameters of the well field and measures to be taken as the water system is initially brought up to capacity. This table should be modified and adjusted as experience with the water system and the well field is gained.

Table 1

Situation	Wells to be Pumping and Pumping rates (in order of use priority)	Targeted Maximum Pumping Levels	System Condition and Comments
Winter Usage – Up to 60 connections	Well 4 – As necessary.	Less than 140 feet to water .	No use restriction. Well 1 can be added when lift distances make doing so cost effective (i.e. > 30 feet difference in lift.
Summer Usage – Less than 40 connections	Well 4 – As necessary up to 25 – 30 gpm..	Less than 140 feet to water (120 feet of drawdown).	No use restriction. Well 1 can be added when lift distances make doing so cost effective (i.e., > 30 feet difference in lift.
Summer Usage – Up to 60 connections. June through September.	Well 4 – Ass needed up to 30 gpm. Well 1 – Constant 8 gpm.	Well 1 – Less than 305 feet to water (208 feet of drawdown ). Well 4 – Less than 205 feet to water (190 feet of drawdown.)	No use restrictions as long as targeted pumping rates and drawdowns are not exceeded.
Winter time shutdown of Well 4.	Well 1 – Up to 20 gpm during repair period.	Well 1 – Less than 305 feet to water (208 feet of drawdown ).	No use restrictions as long as targeted pumping rates and drawdowns are not exceeded.
Summer time shutdown of Well 4 (short duration).	Well 1 – Up to 20 gpm during repair period.	Well 1 – Less than 305 feet to water (250 feet of drawdown ) during repair period.	Initiate conservation measures, at least voluntary use restrictions. Additional restrictions as necessary to remain below drawdown maximums.
Summer time shutdown of Well 4 (long duration).	Well 1 – Up to 12.5 gpm during repair period. Add Wells 3 & 4 as needed. Well 2 – Constant 5gpm Well 3 – Constant 5 gpm	Well 1 – Less than 305 feet to water (250 feet of drawdown ) during repair period. Well 2 – Less than 300 feet to water (200 feet of drawdown ) during repair period. Well 3 – Less than 350 feet to water (250 feet of drawdown ).	Initiate conservation measures, at least voluntary use restrictions. Additional restrictions as necessary to remain below drawdown maximums.
Targeted water levels being exceeded consistently.	Well 4- Reduce flow to meet target drawdown. Well 1 – Reduce flow to meet target drawdown. Well 2 – Constant 5gpm Well 3 – Constant 5 gpm	Well 4 – Less than 205 feet to water (190 feet of drawdown ). Well 1 – Less than 350 feet to water (250 feet of drawdown) during repair period. Well 2 – Less than 350 feet to water (200 feet of drawdown) during repair period. Well 3 – Less than 350 feet to water (250 feet of drawdown).	Initiate conservation measures, at least voluntary use restrictions. Additional restrictions as necessary to remain below drawdown maximums.

Professional Operations and Maintenance

The Cascade View Subdivision will be operated by a County Service District with professional water management personnel or a contractor. The County Service District will be operated under State Law and their own bylaws and ordinances. The District Codes, Bylaws, Policies and Ordinances will contain requirements to meet the objectives of this plan and the requirements imposed upon the Water System by the Conditions of Approval as established by Benton County and the regulations of the Oregon Water Resources Department Water Right Permit and Certificate.

Monitoring System

As with any system it can only be ran as efficiently as there is data to understand how the system is performing. Monitoring of the system is critical to knowing how well the system is performing and formulating plans to increase the system's efficiency both in terms of cost and water conservation.

Aquifer Levels – Four On-site Wells

All on-site wells will have their static (fully recovered from pumping) water levels taken once per week from November 1, 1992, to October 31, 1993.; This will commence the first week of November, 1992. These data define the reference levels (a separate reference level for each well) for use in water management and will be included in the Water Supply System's Annual Report.

The first year's water level data will be used to determine the reference water levels to be used for water management. Two reference levels will be determined. The first will be a "recharge reference level" based upon the high water level expected in the Spring of each year at the end of the recharge season for the aquifer. This reference level will be particularly important for the two wells on-site which will rarely be used (Wells Number 2 and 3). Wells Number 1 and 4 will also have a high water reference level established by alternately shutting down these wells for a recovery period and letting them approach equilibrium with the aquifer. Well Number 4 may require a 48 hour shutdown period while Well Number 1 will probably need a 10 day period because experience has shown it has a much slower recovery rate. In the first year, since use will be very low, only Well Number 4 needs to be online and thus Well Number 1 could easily be read weekly.

The second reference level will be an "average reference level" based upon the average water level in the well for the year. This will be based on weekly readings of water levels for the first year of operation of the monitoring system. The first year of operation is expected to have the least pumping because development will be at a minimum and therefore the highest average water level. In order to avoid the normal summertime drawdown of the well from effectively curtailing well use prematurely (when the system is in full use) the "average reference level" should be examined yearly within the annual report to Benton County and Oregon Water Resources Department (WRD). The relationship of the "average reference level" in the on-site wells to the off-site wells must also be discussed in the annual report.

Using the two reference levels allows for examining whether overdraft or mining of the aquifer is occurring (recharge reference level), and whether yearly drawdowns are increasing, particularly during the season of no recharge.

Off-site Wells

Four existing off-site wells will be selected by the Water Supply System surrounding property owners to be monitoring wells. These wells will be equipped with water level measuring devices by the Water Supply System; the devices will be serviced and maintained by the well owners. These data will be used to determine the static water level in each well once per week from November 1, 1992, to October 31, 1993. These records will be submitted to the Water Supply System for inclusion in the Water Supply System's Annual Report.

Criteria for Water Use Reduction

Water use will be reduced if a drop in static water levels for an on-site well, measured with respect to the average reference level for that well, reaches 25 feet. Water use will be reduced so as not to exceed a drop of 25 feet in static water level for an off-site monitoring well, measured with respect to the average reference level for that well, and it is determined that the excessive drop is due to water use by the Water Supply System.

Water curtailment shall be sustained until the water level recovers to above the 25 foot decline level or until the Department of Water Resources determines, based on the collected data and analysis, that no action is necessary because the aquifer can sustain the observed declines without adversely impacting the resource or senior water rights.

These criteria for judgment will preclude a shallow and/or poorly producing well from controlling the water use of all other users, and will allow for an investigation so that a private well user(s) who over utilizes their own well(s) and cause declines cannot automatically blame the Water Supply System well for problems not related to the Water Supply System operation. This will also prevent overdrafts originating from other sources being blamed on the Water Supply System just because the System alone has a Water Management Plan. The WRD will have final authority to determine interference and prescribe remedies, as mandated under ORS Chapter 537 (Water Right Permits) and Chapter 540 (Distribution of Water, Watermasters). If the System is causing the problem the System will be required to respond by restricting use, to the point of shutting off wells if necessary, in order to mitigate the impact or obtain alternative off-site water sources so as not to further impact the aquifer.

Reservoir Volume

Long term data collection will be used to compute a groundwater reservoir volume. The water level data, along with pumping volume data may allow for the calculation of the storativity of the aquifer(s) around Wells Number 1 and 4. This will be included in the first annual report in which the data can be used with any reasonable accuracy. It is anticipated this will be accomplished the first year there is significant pumping on the well(s), or it will likely not be accomplished at all because of a lack of response between wells.

Reservoir volume is an important number in groundwater management and will be important in updating the Plan. If this data can be collected and analyzed it will be done. By calculating reservoir volume the quantity of water available from each well for withdrawal can be matched to recharge data collected over the year to more accurately determine the sustained yield of the aquifer(s). Aquifers are renewable resources but just like trees we need to know how fast it returns and how big the initial resource is.

Consumption

Data must be collected on the quantity of water used in order to balance the system with the groundwater reservoir and well capacities. Thus each pumping well will be metered in order to determine the daily pumping volume. Each well that is pumped will have the volume pumped recorded at least daily and always at the same time in order to get true 24 hour pumping volumes. Also each service connection will be metered and read at least monthly. A water balance will be calculated to match water pumped with water delivered to determine system leakage rates. Note that meter inaccuracies may also be determined in this manner and discrepancies do not automatically mean water leaks. All discrepancies in the system water balance must be accounted for and irregularities explained by the Contract Operator to the extent possible in writing.

Figures for total system consumption, consumption per service connection (average), and consumption per service connection (total) will be reported by month on an annual basis. This report will be made available to the Benton County Public Works Department, WRD and each service connection on the system. The daily readings for the pumped wells will be provided to Benton County and WRD, and kept on record with the Contract Operator for review by Water Association members. Others may view the public documents on file with Benton County.

Reporting of Data Monthly

For the first year of operation the system will provide monthly reports to the Benton County Public Works Department on the system and the data collected according to the schedule outlined here. After the first year the data will continue to be collected according to this schedule but reporting will be done on an annual basis. This annual report will contain all data collected, an analysis and interpretation of that data as it relates to groundwater and system operations, and any recommendations for modifications to the Water Management Plan.

Benton County will review and approve any modifications recommended. If no comment is received by the County Service District within 90 days of submitting the annual report containing recommended modifications, the modifications will be become a part of the Plan without further review. Any written comments to the recommendations by Benton County will hold the recommendations in abeyance until either approved or rejected by the County.

Monitoring	Daily	Weekly	Monthly	Yearly
Water Levels		Yes
Meter Readings	Yes
Reporting
Water Levels			First Year	First Year
Meter Readings			After 1/01/94	After 1/01/94

Conservation Measures

Conservation measures take two forms within this Plan. First, those measures to be implemented with the normal operation of the water supply system (system). These measures are designed to reduce the average water consumption of each user on the water supply system. They may also reduce peak demands as well. The second set of measures are designed to handle times of water shortage (shortage) due to drought, equipment failure or curtailment of water use enforced by the WRD or other regulatory agency.

Water Saving Devices Mandatory

System – As now mandated by new state building codes and reinforced within this subdivision, all houses will be required to install water saving devices. Low water use faucets, showers, toilets and appliances will be required.

Shortage – During times of short term shortage no new devices could be installed which would be effective, since all such installations were required initially. Additional restrictions on water use such as irrigating restrictions, restrictions on car washing, filling of swimming pools and other water uses may be restricted as deemed necessary by the County Service District.

Spray Irrigation Systems

System – All landscaped yards will be required to install subsurface automatic irrigation systems. Lawn watering will be encouraged to be set to irrigate at night. All shrub and tree watering will be required to be done through drip irrigation rather than spray irrigation.

Shortage – During times of shortage irrigation will be restricted to specific days and times of day. No daylight watering will be allowed. Sprinkling of lawns will be restricted if necessary and banned if required. Shrub and tree watering will be the highest irrigation priority but only if drip irrigated. Non-drip irrigated shrubs and trees will be regulated as if they were lawns. Shrub and tree watering will be prohibited if necessary as well.

Rate Structure with Incentives and Penalties

System ? The rate structure will be modeled initially (for the first 320 GPD) after other Benton County Service District systems and will be billed monthly. Billing will be as outlined in the Draft Water Operation Code (Attachment B).

The County Service District Board may adjust the usage rates, surcharges, penalties, and incentives provided sufficient rates, surcharges, penalties and incentives remain in force to meet the objectives of reducing water usage to a safe sustainable yield and provide sufficient funds to operate the Water Supply System, including contingencies.

Shortage – During times of shortage the Board may place whatever rates and penalties they deem necessary to provide the appropriate incentive to meet the needs of the Water Supply System. Penalties for not complying with restrictions on automobile washing, irrigating, or other Board mandated restrictions on water use can be set and levied by the Board. These penalties can be collected through the regular billing process.

Maximum Annual Usage per Household

System – Each service connection will have a target of 127,750 gallons per year usage (350 GPD), and will be allowed an annual maximum of 179,520 gallons per year (490 GPD). A fee structure is established by the Cascade View County Service District Governing Body that encourages conservation. If water use exceeds the monthly maximum total usage, use and monetary penalties, as established by the Governing Body, will be assessed.

All service connections that exceed their target value (127,750 gallons per year) will be so informed by the operating agency and encouraged to meet this goal. Specific methods for reducing water usage, while maintaining well manicured yards, clean automobiles, and a pleasant home environment may be provided by the agency to all service connections.

The County Service District Board may set new target and maximum values based upon data collected on the aquifer and the Water Supply System wells. In all cases the new values must remain protective of the groundwater resource for sustained yield.

Shortage – Annual maximum usage values will not have a direct bearing on times of shortages other than they may prevent them in the first place.

Landscape Restrictions

System – Lawns and irrigated areas of excessive size will be discouraged. Homeowners will be encouraged to use native plant species well adapted to climatic conditions in this area that will require less watering. Lawn sizes will be encouraged to be small with native shrubs, rock gardens and other lower water use areas. Swimming pools will be required to use covers to reduce water loss. The Water Supply System Governing Board may place restrictions on lawn size, plant species use and any other restrictions they deem necessary to meet the water conservation goals of the Water Supply System.

Shortage – Irrigation use restrictions set by the Board during shortages will allow lawns to go without water first (grass being most able to recover from water loss), then shrubs and trees. Automobile washing will be time restricted according to an "odd - even" scheme or another suitable system appropriate for the severity of the shortage.

Private Wells

System – No private well use will be allowed within the Water Supply System boundaries, including those service connections which become part of the Water Supply System but are not part of the Cascade View Subdivision proper. Outside users who wish to connect to the system must assure there is no cross connections with their existing water system and their existing well must be disconnected from the power supply.

Shortage – No impact on the short term shortages on private wells.

Monthly Reporting

Records of the Water Supply System and off-site monitoring records will be kept at a central location and will be open to members of the District. Copies of these records will be provided on an annual basis (after the first year) to the Benton County Public Works Department where they may be examined by others. Data on individual service connections, such as penalty amounts, will not be reported, though water usage by connection (without names) will be provided for the public record. Data will be collected on a schedule as listed above.

Costs of Off-site Connections

All actual off-site connection costs will be borne by the connecting party. A maximum of 17 off-site connections will be allowed to the system. All off-site connections will be subject, retroactively, to all the conditions and privileges of this Management Plan, and the laws and policies of the County Service District. If the conditions are not met the connection will be severed until the responsible party demonstrates a willingness and capability to meet the conditions.

Summary

This is the first Water System Management Plan in this local area and one of the first in the state. Other water systems which do not operate with an effective water management plan, data collection schedule, analysis requirement, interpretation of their system performance or impact do so at their own peril, and perhaps, the peril of those around them. Even more importantly none of many private well owners (who greatly outnumber water system users) have any plan or incentive to conserve water.

With this plan the Cascade View Subdivision can lead this portion of the Corvallis Area Community into some form of water conservation awareness. This Plan addresses all the areas of water conservation and puts in place a framework which allows for future modification so that the Plan matches the resource and the ultimate level of use. To be effective this Plan must be a living document, periodically reviewed and modified. This Plan allows for water use on a sustained basis for this subdivision and its neighbors.

County Service Districts are commonly used in Oregon to provide and finance a variety of services including, but not limited too; water, sewer, library, public safety, fire, and extension services.