MOUNTAIN HOUSE COMMUNITY SERVICES DISTRICT To provide responsive service to our growing community that exceeds expectations at a fair value

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1 MOUNTAIN HOUSE COMMUNITY SERVICES DISTRICT To provide responsive service to our growing community that exceeds expectations at a fair value STAFF REPORT AGENDA TITLE: Mountain House Creek Operations and Maintenance Issues MEETING DATE: April 13, 2016 PREPARED BY: Doug Louie, Operations and Maintenance Superintendent RECOMMENDATION: No recommendations at this time - Discussion only. DISCUSSION: Mountain House Creek was designed and constructed to be a multi-purpose facility. Its primary purpose is to serve as the critical, engineered flood control facility for the entire community of Mountain House. Without this flood control facility, the community of Mountain House could be at risk to flood. Mountain House creek is also designed to enhance the community well-being and aesthetics by integrating the environment into the community providing walking trails, recreation, and visual landscape opportunities. The key to successful management of this key critical infrastructure is balancing potentially competing demands. For various reasons, Mountain House Creek currently suffers from several deferred maintenance issues resulting in a system out of balance that could potentially contribute to future flood management problems. This discussion will provide facts and information upon multiple levels to form the basis from which to take action, involving one of the most important engineered infrastructure elements in Mountain House. Above all, the integrity of the Storm Water Facility which makes up a large portion of Mountain House Creek, must not be compromised; however due to an encroaching beaver habitat it is clearly too late and several areas must be repaired. By the end of the discussion, we will establish priorities and provide clarity as to the clear intent of the MHCSD to both maintain the vital Storm Water Facility and to coexist with the presence of wildlife. The Restoration of Mountain House Creek is described in The Mountain House Creek Phase One Habitat Restoration Plan (Specific Plan 1, June 2003). Restoration associated with Phase One involved the establishment of a new 200 feet wide corridor around existing creek and wetlands. Approximately 54 acres of native vegetation were restored to the wetlands upper buffer habitats within the creek corridor. The existing tributary, wet meadow and perennial marsh habitats were retained and enhanced. Areas adjacent to the creek that were used for agriculture and pasture land were restored to seasonal marsh, riparian, native prairie and oak woodland habitats.

2 Restoration of Mountain House Creek corridor also included the construction of grassed swales and a series of wet and dry detention basins that provide for regional BMP treatment of storm water to entering Mountain House Creek. The Goals for the creek restoration were to: Establish a diverse, self-sustaining riparian system throughout the corridor Provide flood protection for adjacent land and infrastructure Provide recreational use consistent with the protection of created habitats Minimize the impact of infrastructure crossing the creek Provide for treatment of all storm water draining to the creek prior to their entry into the Mountain House Creek. These five goals as outlined in the 2008 Mountain House Storm Water Management Program were referenced by staff to set direction and form the basis for ongoing maintenance that will be performed. It is clearly documented that the area that is now Mountain House Creek was nothing more than pasture and farm land before development began. Mountain House Creek was originally carved into this once flat farmland and engineered into a storm water facility. In addition to the storm water facility, Mountain House Creek was also designed to serve as a multi-purpose facility to also provide a scenic corridor, recreation, and a park like setting amidst an engineered, constructed habitat where wildlife was expected to flourish within wetland areas and the Waters of the US (WoUS). In 2009 the first signs of beaver activity within the creek were noticed near Central Parkway and Main Street. It wasn t until 2011 that significant damage was becoming noticeable. Reports to the MHCSD started increasing as the magnitude of damage expanded. The presence of beavers in Mountain House Creek was never anticipated nor was it mentioned in the Mountain House Master Plan. Research began to review mitigation options. An informational report presented to the Board of Directors on October 2011 provided information on beaver behavior, location of beavers in Mountain House Creek, damage estimates and mitigation options. For the next two years, the impact of beaver damage remained relatively low. It was limited to approximately 30 to 40 damaged trees that were eventually removed. Management efforts to provide for potential coexistence with the beavers were implemented. Preservation of tree stumps from beaver damaged trees was left for the purpose of becoming beaver fodder from new sucker growth. By the beginning of 2014 the number of damaged trees increased. On April 14 th 2014 An Eagle Scout Project began in partnership with the MHCSD to selectively cage certain trees for protection and others left exposed to be chewed. This was a plan to create a self-sustaining beaver area. In the following year several more beavers were spotted and had taken up residency near Bethany School. It was evident at this time they were causing damage to levees and burrowing into banks. Upon discovering breaches in Mountain House Creek levees and the water flooded BMPs (caused by the building of beaver dams) it became clear that costly infrastructure repairs had to be planned immediately. Mountain House is required as a MS4 operator to abide by the EPA

3 under the NPDES permit requirements. This is regulated and monitored for compliance by the Central Valley Regional Water Quality Control Board (CVRWQCB). Penalties for illicit discharges and noncompliance can be very costly. Re-establishing the integrity of the Storm Water Facility to its original design to avoid these penalties has become a top priority. The CIP Budget includes funds for removal of dams and mitigation of beavers. Staff began the process to mitigate the beaver issue and also began estimating the extent and magnitude of the damage. Several inspections were conducted over a period of several weeks in the summer of The inspections established the severity and locations of the damage; however, they also revealed that access to the damaged areas was limited. The lack of access points and staging areas for equipment proved to be a limiting factor in the planning of repairs to the facility. This added an additional element in the planning. Before bidding or repair work begins, a network of roadways and paths must be established. These major steps also include the permit application processes that include the Department of Fish and Wildlife and the Army Core of Engineers. Staff is currently working on plans to complete these tasks. During these inspections, Ronald Rovansek, Ph.D. P.E. of PACE Advanced Engineering worked with staff to assist with this effort. Mr. Rovansek is currently under contract to complete a Mountain House Creek Operations & Maintenance Manual (O&M Manual). Dr. Rovansek was a member of the original team that helped design and construct the Mountain House Creek corridor. Mr. Rovansek is providing insight and guidance in building a strategy for the long term maintenance of the creek and storm water facility. This also includes guidance on the management of wildlife, including, beavers. The coexistence of wildlife that directly affects the safety and welfare of the public is dealt with in many ways. The acceptance of coexisting with wild animals brings its share of liability. Besides the possible financial burden of fines and penalties from a breached Storm Water Facility, the District also assumes liability in the event of floods should they occur as a result of debris dams and other backwater effects. In a worst-case-scenario, residents of Mountain House could be required to purchase flood insurance that would cost thousands of dollars per year per parcel. Additionally, beaver damaged trees may also fall upon park users and beaver burrows along creek banks may collapse underfoot resulting in severe injuries or fatality, thus creating further liability for the MHCSD. To put this into perspective, it is easy to assume that if a Mountain Lion is wandering near a neighborhood, that lion must be removed, as would a bear in a community in the mountains, pythons in the everglades, or any other wild animal. This is a sad unfortunate occurrence in many communities; however, it is a management responsibility of the MHCSD. Experts claim new beavers will populate the creek shortly after existing beavers are removed. From an engineering standpoint, the proper course of action will be to repair the Mountain House Creek infrastructure and establish a consistent inspection and maintenance regimen in spite of reoccurrence. The presence of beavers will add an uncertain element related to the financial needs for ongoing repairs. Repetitive repairs are costly and inefficient. It is clearly evident that in controlling the sequence of repairs and the financial burden that follows, beaver removal is the only option. As unfortunate as this may be and the fact that the beavers will still re-populate, it will still allow additional time between re-population to repair and maintain the facility.

4 One option we may wish to consider is to designate several areas along the creek where beavers might build a dam or a lodge a safe distance away from the engineered Storm Water Facility. This option potentially could offer three zones: Red: No beaver tolerance due to the sensitivity of the location of BMP basins and flooding concerns. Yellow: Beaver activity with little or no evidence of multiple incidents of damage; and Green: Open areas away from BMPs that will support beaver dams and resultant rising water will not affect the Storm Water Facility. Obviously the Red Zone will require removal of the animal. The other two zones are manageable and must be controlled by the authority of the MHCSD. Volunteer efforts by certain groups can join the MHCSD to apply preventative measures in Yellow and Green Zones. The activity of these groups must be controlled and managed through the MHCSD. ESTIMATED INITIAL FISCAL IMPACT: Beaver Dam(s) Removal - $70,000 Berm/Bank Repairs - $10,000 Silt Removal (dredging) - $10,000 Debris Removal (branches, limbs, misc. debris) - $40,000-$60,000 Tree replacement - $100,000 Creek Access Improvements - $50,000 - $100,000 Total: $280,000 to $350,000 ESTIMATED ANNUAL FISCAL IMPACT (upon completion of initial year): Annual weed abatement riparian area to the WoUS - $60,000 Beaver dam removal, berm and bank repairs and silt removal - $50,000 Debris removal (branches, limbs, misc. debris) - $10,000 Tree replacements - $5,000 Total: $125,000 STRATEGIC PLAN OBJECTIVE: This report on Mountain House Creek Operations and Maintenance, applies the pillars of (Mission, Values and Vision) in the improvement of Stormwater Management under the umbrella of Sewer Service. Priority Identification - Sewer Service: Meet CVRWCB permit and regulatory requirements for MS4 Well maintained infrastructure to ensure reliable service Keep rates cost effective in an increasing regulatory environment and escalating O&M cost. Storm water permits and reporting Beaver abatement Collection system maintenance

5 Suitable public use of creek corridor ATTACHMENTS: None c: District Counsel