Water Demand Estimation and Design Guidelines
1. Water Demand Estimation
- Proponents must provide the City with the expected average day, maximum day, and peak hour water demand for the proposed development.
- All assumptions must be explicitly stated and properly documented.
- Water demand calculations must be stamped and signed by a Professional Engineer licensed to practice in the Province of Manitoba.
- All units must be in metric; water flows must be in L/s.
|Average Day Water Demand:||ADD =||Daily average water demand|
|Maximum Day Water Demand:||MDD =||1.6 x ADD|
|Peak Hour Water Demand:||PHD =||2.5 x ADD|
Residential water demand
|ADD:||Average daily water demand = 225 L/capita/day + 10%|
|Single Family Dwelling|
* where actual dwelling units are known, these values should be used
Non-residential water demand**
|Light Industrial||ADD:||22,500 L/ha/day|
|Wet Industrial||ADD:||33,600 L/ha/day|
** where actual water demand is known, these values should be used. For design purposes, where specific land uses are known, water demand can be derived from literature values i.e. AWWA Water Distribution Systems Handbook; references must be included with design assumptions.
2. Water Design Guidelines
- Fire flow analysis:
- Fire flow targets must follow guidelines set by the Fire Underwriters Survey, found within Part II of the “Water Supply for Fire Protection” document. Please contact Fire Underwriters Survey for this document.
- Available fire flow must be stated at 140 kPa (20 psi) residual during Maximum Day Demand
- An allowance for hydrant losses must be included in the hydraulic modeling of fire flows
- The following fire flow targets are suggested in the absence of building construction details based on the Fire Underwriters Survey ‘Water Supply for Fire Protection’:
- Residential Single-family: 100 L/s
- Residential Multi-family: 200 L/s
- Streetside Commercial: 250 L/s
- Elementary Schools: 167 L/s
- Junior and Senior High Schools: 267 L/s
- Institutional: 250 L/s
- Industrial: 383 L/s
- Hydraulic model analysis:
- Hazen-Williams C-value = 120 for water main diameter <= 200 mm
- Hazen-Williams C-value = 130 for water main diameter > 200 mm
- WWD will provide pressure / flow curves at requested feedpoints to facilitate hydraulic modeling analysis
- Peak hour demand pressure analysis:
- Minimum water main pressure during peak hour demand = 207 kPa (30 psi)
- Minimum feeder main pressure during peak hour demand = 310 kPa (45 psi)
3. Water Layout Standards: Public Right-of-Way
- Water mains must be designed:
- with 2.5 m ground cover minimum.
- with minimum diameter of 150 mm.
- Maximum hydrant linear spacing to be 90 m with 75 m radius of protection.
- Hydrants must be placed at high points in the water main profile.
- No more than 2 hydrants are to be installed between main line valves.
- Hydrants and valves are to be placed on projected property line where possible.
- Suggested maximum spacing between main line valves is 150 m.
- Minimum 2 valves at every water main tee, 3 valves at every water main cross.
- All bays and cul-de-sacs must be isolated.
- Maximum 20 services between valves.
- Maximum 20 customers are to be supplied from a single feed.
- Final layout is subject to review for flushing and maintenance procedures.
- Dead end water mains must have a hydrant installed at the end.
- All water mains, appurtenances, and service connections must be constructed in accordance with the latest revision of the City of Winnipeg Standard Construction Specifications. For further information regarding City of Winnipeg Construction Specifications see Standard Construction Specifications
4. Water Servicing Guidelines: Private Services
- Minimum water fire service size is to be 150 mm.
- Service valves for fire services, or combined fire-domestic services are to be placed 1 m from the City water main
5. Simulated Hydrant Flow Tests
- If available system pressure and flow are required for design, we can provide a simulated hydrant flow test upon request.
- To request a simulated hydrant flow test please contact firstname.lastname@example.org
Contact us for more information or if you have questions.