When wildfire threatens homes and buildings beyond dependable municipal hydrant coverage, water for structural firefighting becomes an immediate operational concern. Planning before wildfire season gives project teams time to coordinate source capacity, access, and delivery with the site and responding fire department.
Where Can Firefighting Water Come From?
Potential water sources have different technical and operational considerations.
| Possible Water Source | Technical Considerations |
|---|---|
| Municipal hydrants | Available flow, residual pressure, system demand, and hydrant coverage |
| Water carried by fire apparatus | Onboard volume, refill location, round-trip cycle time, and shuttle or relay capabilities |
| Wells | Sustained yield, pump output, power supply, and emergency availability |
| Ponds, streams, or reservoirs | Seasonal water levels, freezing, sediment, debris, and intake access |
| Dedicated fire cisterns | Available footprint, burial conditions, filling method, and replenishment |
Documenting these characteristics gives the project team and responding agency a shared reference for evaluating the available options.
Planning a Firefighting Water Supply
A project-specific basis of design is typically developed before tank selection and piping layout. The responsible parties, approval process, and required documentation vary by jurisdiction.
- Confirm the project criteria.
Determine which agency or official has approval authority, then confirm the applicable codes and criteria for fire flow, duration, acceptable supply methods, and fire department connections. NFPA 1142 may be relevant when adopted, referenced, or required for alternative water supplies serving structural firefighting. - Determine the required usable volume.
Usable volume may differ from nominal tank capacity because of outlet elevation, minimum operating water level, piping arrangement, and project-specific allowances. The appropriate project professionals determine which calculations and allowances apply. Darco Tanks provides additional information about fire cistern capacity planning. - Review drafting and hydraulic conditions.
Elevation difference, static lift, pipe diameter, pipe length, fittings, and water level can affect fire-cistern flow during drafting. Project-specific analysis can evaluate these conditions in relation to the proposed system and local fire department equipment.
- Review the site and apparatus interface.
Depending on local requirements and site conditions, plans may need to address apparatus routes, load-bearing surfaces, turning space, working clearances, connection locations, and operating positions. - Plan for testing and continued readiness.
Project documents and operating plans should assign responsibilities for filling, acceptance testing, inspection, water-level monitoring, freeze protection, maintenance, and refilling, as applicable.
For new developments, this review may occur alongside decisions about roads, utilities, grading, and building layouts. At existing sites, the appropriate scope depends on current infrastructure, proposed changes, and the local review process.
Where an Underground Fire Cistern May Fit
A dedicated fire cistern provides a fixed water reserve at a designated location when approved for the project.
Applications for Dedicated Storage
Potential settings include residential subdivisions, rural and mountain communities, ranches, remote commercial developments, schools, and community facilities.
Cistern requirements may be identified during the review of a new development project or an upgrade to existing fire-water infrastructure.
Single- and Multi-Tank Configurations
The approved design may specify one tank or multiple interconnected tanks based on required storage volume, available footprint, burial conditions, and system configuration.
Fiberglass Tank Considerations
Fiberglass-reinforced plastic provides corrosion-resistant underground water storage. Available fittings, manways, vents, level indicators, refill assemblies, and drafting connections can be coordinated with the project-specific design, while underground placement limits visual impact when appropriate for the site.
Firefighting Water Is One Part of Wildfire Preparedness
An engineered water supply can support emergency operations, but it cannot eliminate wildfire risk or ensure property protection. A broader strategy may also address:
- Vegetation and fuel management
- Defensible space around buildings
- Fire-resistant construction
- Emergency access and evacuation planning
- Reliable communications
The U.S. Fire Administration offers community wildfire preparedness resources. NFPA’s Firewise USA® program provides a framework for organizing community wildfire risk-reduction efforts.
Discuss Your Project With Darco Tanks
Use Darco Tank’s fire cistern project checklist to organize the project location, site information, and any available requirements or drawings.
Then contact Darco Tanks to discuss underground fiberglass tank capacities and configurations that may fit the established project criteria.
