Item #06
Date: September 19, 2023
To: Mayor and City Council
From: Jim Schaad, City Manager
Subject: Yuba Water Agency Grant to Manage Ellis Lake Plant Growth Recommendation:
Pass a Motion to 1) authorize the City Manager execute a contract or contracts to chemically treat aquatic weeds in the lake for an amount not to exceed $60,000, 2) authorize the City staff to submit a grant application to the Yuba Water Agency to fund treatment of Ellis Lake to mitigate aquatic weeds and algae blooms in the amount of $300,000, and 3) authorize the City Manager to execute the grant should it be awarded by the Agency.
Rationale for Recommendation:
The City desires to improve amenities at Ellis Lake in order to develop a regional recreation and tourism venue, provide residents with high quality outdoor recreation activities, and promote development/ redevelopment in the area. On July 18, 2023, Council approved a consulting agreement with IGServices to develop an Ellis Lake water quality implementation plan in the amount not to exceed $35,000. Initial investigation is that short-term treatment of the lake is necessary to control algae and aquatic weeds until a long-term water quality management solution can be developed.
Background:
Ellis Lake is a prominent 31-acre recreational lake with significant historical value to the City of Marysville.
Unfortunately, the lake has suffered from poor water quality, causing the lake to be unattractive, unhealthy, and less than desirable for outdoor recreation activities. The City Council has considered the redevelopment/rehabilitation of Ellis Lake a priority, with improvements listed as goals in the last several years’ budget and strategic planning discussions. The lake suffers from persistent algae blooms and aquatic weed growth caused by high nutrient (phosphate) levels, poor circulation and warm temperatures.
In fiscal year 2021/22 the Yuba Water Agency provided $142,300 in funding for the application of a phosphorous sequestration agent and removal of non-native Carp from Ellis Lake in an initial attempt to improve lake water to a cleaner and healthier condition. The Carp removal and phosphate reduction treatment had positive effect in reducing phosphates in the short-term, but the efficacy of the phosphate treatment lasted for a shorter than expected duration, requiring a second treatment to curb algae blooms.
City staff completed the activities contained in the grant scope at a cost of $112,343.95, well under the estimated $142,300, leaving a balance of $29,956.05. The Yuba Water Agency has approved use of this funding balance to complete a water quality implementation plan. Additionally, a motion to appropriate Item #06
an additional $150,000 for activities related to this effort was approved in the City’s FY2023/24 budget proceedings.
Discussion & Analysis:
Mr. Dan Bergmann with IGServices has gathered information from multiple relevant sources, including current and former City staff, the State Water Resource Control Board (SWRCB), Yuba Water Agency (YWA) staff, environmental consultants, lake management providers, manufacturers of treatment products and the City Engineer, MHM Incorporated. A preliminary report from Mr. Bergmann is expected to be completed by October 3rd.
Mr. Bergman, MHM, and City Staff have been developing estimates for reduction of long-term reduction of nutrients in the lake water, either by treating the current well water source, or conveying water from the Yuba River as had been done in the past. Research has yielded a preliminary estimate for conveying water from the Yuba River. MHM’s initial estimate to convey nearly phosphate free water from the Yuba River is approximately three million dollars. The timeframe to acquire a water contract, secure funding, negotiate easements, obtain appropriate permits and construct the infrastructure is estimated to be two years. Cost estimates for well water treatment are still being determined through discussions with manufacturers of treatment products and lake treatment companies. All experts consulted agree that the treatment of the lake water with herbicides and algaecides as well as reduction of phosphorous levels in the water must be an ongoing maintenance activity.
Additionally, through interviews with current and past City employees it was verified that treatment of the lake using chemical and/or mechanical means was performed in the past to control weed and algae growth. Former employees also indicated that the most effective methods were through chemical means (algaecides such as chelated copper and herbicides such as Diquat) and that treatment was required whether the water source was the Yuba River or existing well. Lake management specialists have also indicated that treatments such as this are the most effective means to control algae blooms and aquatic weed growth, and will be required to some extent, regardless of the water source.
Staff have therefore applied for an NPDES permit from the State Water Resource Control Board and hope to have secured the permit by mid-October. Staff would work with licensed herbicide/algaecide applicators to treat the lake. In order provide more immediate improvements to the lake water quality staff recommends as soon as the permit is secured that treatment is performed based on lake management specialist’s prescribed dosage recommendations, and in accordance with the SWRCB permitting processes. A portion of the $150,000 appropriate in the 2023/24 budget would be used to fund the activity.
Staff also proposes that the City Council approve the application for a grant to the Yuba Water Agency for a grant that would fund ongoing treatment of the lake water to manage algae and weeds until a longterm management strategy is implemented.
Environmental Review:
This activity is considered maintenance and is not considered a project for the purposes of CEQA.
Fiscal Analysis:
Funding for this activity has been included in the FY2023/24 budget. Funding for ongoing treatment will be requested from the Yuba Water Agency if council approve the submittal of an application.