Update #4

Stormwater Standard Operating Procedures

Stormwater systems are typically designed to convey runoff from “every‐day,” minor storm events. Stormwater assets protect the road traveling public, property owners, and businesses from the consequences of uncontrolled stormwater. Washoe County is responsible for cleaning and repairing stormwater facilities within Washoe County right‐of‐way or Washoe County maintained drainage easements. Washoe County Roads Team continually inspects and maintains the stormwater conveyance system based on risk-based priorities, equal to asset condition and asset failure consequences.

Our ditch maintenance program includes a variety of specific activities and specialized equipment. These activities include ditch cleaning with an excavator, mowing weeds, applying herbicide, and cleaning culvert pipes with a vacuum truck. Our ditch maintenance program represents the largest effort in labor hours on average than any other road maintenance activity, including paving and snow removal. Since 2008, we have averaged over 15,000 hours of ditch maintenance annually – this is approximately 20% of our entire annual labor effort.

Not all of the ditches are “created” equal. Some have performed very well over decades, while others need more frequent maintenance based on a variety of factors included highly erosive soils resulting in heavy sedimentation, heavy vegetation growth, energy of run-off, etc. Additionally, some homeowners take it upon themselves to keep the ditch in front of their property free and clear of vegetation and debris. Several factors impact this schedule including, winter/spring precipitation, heavy snow removal years and emergency response to localized flooding from thunderstorms.

We are constantly prioritizing our maintenance activities based on available resources and risk analysis. In an effort to offer exceptional customer service, we recently implemented a new work order system. This system offers a platform for administrative support staff answering the calls to have direct access to the status of the work orders including notes left by the Supervisors and expected dates for the work to be completed. The public can call Washoe County Roads at 775.328.2170, and this number is answered 24/7 for emergencies.

In 2023, the Community Service Department’s Roads Team made a significant advancement in the approach to managing stormwater infrastructure. They have implemented tools and technology that allows field staff to use their limited resources to provide the most value and make more informed decisions. This is completed by using Esri Field Maps, a mapping platform that allows front line staff collect, view, and update infrastructure information in the field. Information like, the location, type and count of assets, their condition, maintenance history, and existing work order requests. The adoption of Esri Field Maps marks a significant step forward in our commitment to maintaining a robust and reliable stormwater management system. We are proud to offer enhanced services to our community.

Hidden Valley Stormwater Facts

Hidden Valley Region Stormwater Asset Inventory
- Drainage Inlet Structures – 224
- Manholes - 140
- Pipes - 468 (43,368')
- Conveyance Ditches - 181 (24,821')
- Detention/Storage Basin - 1 (40,633 sqft)
- Easement - 43 County Maintained (361,708 sqft)

Hidden Valley Regional Park Retention Ponds
- North Park Retention Pond and Eastern Flat Bottom Ditch
  - Installed in 1967-1968 for the protection of the park amenities
- Planned major maintenance frequency: 20 year
- Date of last major maintenance: 2010
- Planned inspection frequency: 10 year or after large storm events
- Last inspection in 2018
Hidden Valley Region Stormwater Maintenance (removal of sediment from assets and inspection of structural integrity)
- Average Annual Cost: $24,716.56
- 3 days before the flash flood, on July 18, the Roads Team was completing stormwater drainage easement maintenance