Project Grade 10 Careers & CTE
Tannoch Lake Hydro: Planning an Operator's Generation Week
A grade 10 careers project in which teams work as hydro station operators, planning a week of generation within lake level, fish flow, and turbine limits.
Objectives
- Students will convert a river inflow forecast among cubic feet per second, acre-feet per day, and feet of lake level.
- Students will build a seven-day generation plan that stays inside turbine, lake level, and instream flow limits.
- Students will write a shift turnover briefing that an incoming operator could act on without asking questions.
Vocabulary
- Acre-foot
- The amount of water it takes to cover one acre of land, about the size of a football field, one foot deep. Western states use acre-feet to measure large amounts of water.
Also: dispatch, shift turnover, instream flow, on-peak, spill
Teacher overview
An operator at a hydroelectric station does not simply turn the turbine on and leave it running. Each shift, the operator decides how much water to release, when to release it, and what to leave in the lake for the days ahead. Over four sessions, teams take that role at the fictional Tannoch Lake Hydro Station and plan a full week of generation. The misconception this project corrects is the belief that a dam operator should generate whenever water is available, when in practice the release is capped at both ends, because the river below the dam must keep a minimum flow and the lake must hold enough water for the rest of the week. Teams deliver a seven-day dispatch plan, a lake level ledger, and a written shift turnover briefing.
Project Brief
Driving question: How should the week's water be released so the station earns the most during high-price hours and still meets every limit?
Scenario: The fictional Okenshaw Power and Water District runs Tannoch Lake Hydro Station on the Gaulden River. Teams work as the operators on the day shift. Each team plans the coming seven days and hands the plan to the next crew.
Given data, from the fictional district's forecast and limits sheet:
| Day | Forecast inflow to the lake |
|---|---|
| Monday | 210 cfs |
| Tuesday | 195 cfs |
| Wednesday | 180 cfs |
| Thursday | 240 cfs |
| Friday | 260 cfs |
| Saturday | 170 cfs |
| Sunday | 160 cfs |
Limits, all set for this fictional station:
- The turbine passes at most 320 cfs. Below 90 cfs it runs rough, so the unit is either off or above that figure.
- The river below the dam must carry at least 60 cfs at every hour. A bypass gate can supply that flow when the turbine is off.
- The lake sits at elevation 1,262.0 feet on Monday morning. It must finish Sunday at or above 1,258.0 feet.
- The lake spills above 1,268.0 feet, which wastes water, and it may never drop below 1,240.0 feet.
- One foot of lake level equals 200 acre-feet of storage. The district's worksheet rounds one cfs running for a full day to 2 acre-feet.
- The high-price window runs from 2 p.m. to 8 p.m. Water released in those six hours earns three times the off-peak rate.
Final deliverable: A dispatch packet for the fictional station manager. It holds three parts. Part one is a seven-day table of generation hours, turbine flow, and bypass flow. Part two is a ledger of lake level at the end of each day. Part three is a one-page shift turnover briefing for the incoming crew. The briefing must name the day with the least margin and say what the next operator should watch.
Milestones
Session 1, put the forecast in three units: Teams take each day's inflow in cfs. They convert it to acre-feet for the full day. They convert that to feet of lake rise. Output: a seven-row table with all three units and a sentence on which unit is easiest to explain to a manager.
Session 2, draft the week: Teams choose generation hours and turbine flow for each day. They add the bypass flow needed in the off hours. They total each day's release in cfs-days and in acre-feet. Output: a first draft of the seven-day dispatch table with daily totals.
Session 3, run the ledger and fix the breaks: Teams subtract each day's release from that day's inflow. They turn the difference into a change in lake level. They then check every rule for every day. Any day that breaks a rule must be redone. Output: a corrected ledger with a check mark column for each limit and a short note on the price trade-off the team accepted.
Session 4, hand off the shift: Teams write the one-page turnover briefing and read it aloud to another team, who act as the incoming crew. The incoming crew may ask three questions. Output: the briefing, plus the three questions and the answers given.
From Water for Schools (waterforschools.org). This material is in the public domain (CC0) and may be copied, edited, and shared freely.
Rubric
| Criterion | Emerging | Developing | Proficient | Advanced |
|---|---|---|---|---|
| Unit conversion | Conversions are missing or units are mislabeled | Some conversions are correct, yet the table is incomplete or mixes units | All seven days are converted correctly to acre-feet and to feet of lake level | Conversions are correct and the team explains which unit fits which audience |
| Dispatch plan | The plan states hours without flows, or exceeds turbine capacity | The plan sets hours and flows, yet ignores the high-price window or the minimum turbine flow | The plan sets hours and flows for all seven days and respects turbine limits | The plan respects every turbine limit and concentrates release in the high-price window wherever the other rules allow |
| Lake level ledger | No ledger is produced, or the level is never updated | The ledger is started, yet arithmetic errors leave the ending level wrong | The ledger tracks each day correctly and ends at or above the required level | The ledger is correct, ends above the required level, and shows the margin left on the tightest day |
| Turnover briefing | The briefing restates the plan with no warnings | The briefing names the plan and one risk, yet leaves the incoming crew guessing | The briefing names the plan, the tightest day, and what to watch | The briefing does all of that and gives the incoming crew a clear instruction if the inflow forecast proves wrong |
Differentiation
Support
Provide the Monday and Tuesday rows of the conversion table already completed, so teams can copy the method down the remaining five rows. Offer a ledger template with the starting lake level filled in and a column already labeled for each limit that must be checked.
Extension
Ask teams to redo the week with the Friday inflow cut in half, which is the kind of forecast error operators plan around, and to report how much off-peak generation or lake level margin they had to give up to still finish Sunday above the required lake level, and whether any high-price hours had to be cut.
ELL supports
Pre-teach dispatch, turnover, bypass, and spill with a simple cross-section drawing of a dam, a turbine, and a bypass gate. Allow the turnover briefing to be delivered orally first, with the written version completed afterward, and supply sentence frames for stating the tightest day and the reason.
Extensions
Teams can compare their plans with one another and count how many arrived at different schedules that all satisfy the limits, which is a useful lesson about problems with many workable answers. A local utility or power agency staff member could review two plans and describe how their own shift turnover documents are written and checked.