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Worksheet Grade 10 English Language Arts

Reading the Amberline Reservoir Drawdown Order

A grade 10 worksheet on following a written reservoir drawdown order precisely, including its exceptions, with twelve items on rates, volumes, and conversions.

Objectives

  1. Students will locate the operating limits stated in a written drawdown order.
  2. Students will apply the exceptions in a procedure to cases that differ from the ordinary one.
  3. Students will carry out the unit conversions the order requires to report a release rate.

Vocabulary

Drawdown
Drawdown is how far the water level in a well drops when a pump pulls water out. The harder and longer you pump, the bigger the drawdown gets.
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: outlet gate, release rate, elevation

Teacher overview

Operating orders for dams are written as numbered steps that carry legal force, and the exceptions inside them matter as much as the main instructions. This worksheet gives students a fictional standing order for lowering a small water-supply reservoir before a gate inspection, then asks them to work inside its limits. Several items can only be answered correctly by noticing a clause that changes the ordinary rule, which is the reading skill the worksheet is built to practice.

Reading the Amberline Reservoir Drawdown Order — Grade 10 English Language Arts
Name: ____________________________ Date: ______________

Student Worksheet

Everything below is fictional. Northline Water District, Amberline Reservoir, and every figure in the order were written for this exercise. Read the order, then answer questions 1 through 12. Use these conversions where you need them: one cubic foot per second equals 448.8 gallons per minute, one million gallons per day equals 1.547 cubic feet per second, one acre-foot equals 325,851 gallons, and one foot of water depth equals 0.433 pounds per square inch of pressure.

Northline Water District, Standing Order 14: Amberline Reservoir Autumn Drawdown

Step 1. Read the pool elevation at the dam gauge before touching any gate. This order applies only when the pool is at or above elevation 812.0 feet.

Step 2. Open the low-level outlet gate in ten equal increments. Hold for 30 minutes after each increment, including the last one.

Step 3. Keep the total release at or below 40 cubic feet per second at all times.

Step 4. Do not lower the pool faster than 0.5 foot per day. Exception: while the weather service has a flood watch posted for the basin, the operator on duty may lower the pool as fast as 1.0 foot per day.

Step 5. Record the pool elevation and the release rate in the gate log every four hours.

Step 6. Stop the drawdown when the pool reaches elevation 806.0 feet. Exception: stop at elevation 808.0 feet instead whenever the raw-water intake screen is in service.

Step 7. Notify the Amberline hatchery at least 12 hours before the first gate movement. No notice is required when the total release stays below 5 cubic feet per second.

Step 8. The pool surface covers 48 acres across the whole range of this drawdown. Report each day's release to the district office in gallons per minute and in million gallons per day.

  1. What is the highest total release rate Step 3 allows at any time? Give your answer in cubic feet per second.
  2. The raw-water intake screen is in service today. Under Step 6, what is the lowest pool elevation the operator may draw the reservoir down to? Give your answer in feet.
  3. Step 2 calls for ten equal increments with a 30-minute hold after each one, including the last. How long does the full opening sequence take? Give your answer in hours.
  4. Convert the Step 3 limit of 40 cubic feet per second to gallons per minute.
  5. Convert the Step 3 limit of 40 cubic feet per second to million gallons per day. Round to one decimal place.
  6. The pool starts at elevation 812.0 feet and no flood watch is posted. Working at the fastest rate Step 4 allows, how many days does it take to reach elevation 806.0 feet?
  7. A flood watch is posted for the whole drawdown. Working at the fastest rate the Step 4 exception allows, how many days does the same 6.0-foot drop take?
  8. The pool surface covers 48 acres. How many gallons leave the reservoir when the pool drops one foot?
  9. How many acre-feet leave the reservoir across the full 6.0-foot drawdown from elevation 812.0 feet to elevation 806.0 feet?
  10. Water stands 40.0 feet deep above the low-level outlet gate. What is the water pressure at the gate in pounds per square inch?
  11. The plan for today calls for a steady release of 9 cubic feet per second. Does Step 7 require advance notice to the hatchery? Answer yes or no.
  12. Explain in two or three sentences why the order lets the operator lower the pool twice as fast while a flood watch is posted, even though the slower rate is the normal rule.

From Water for Schools (waterforschools.org). This material is in the public domain (CC0) and may be copied, edited, and shared freely.

Answer Key
  1. Answer: 40 cfs. Step 3 states the limit directly and applies at all times, so no calculation is needed.
  2. Answer: 808.0 feet. Step 6 sets the ordinary stopping point at 806.0 feet, but the exception raises it to 808.0 feet whenever the raw-water intake screen is in service, which is the case here.
  3. Answer: 5.0 hours. Ten increments with a 30-minute hold after each gives 10 x 30 = 300 minutes, and 300 / 60 = 5.0 hours. Students who answer 4.5 hours have dropped the hold after the final increment, which Step 2 explicitly includes.
  4. Answer: 17,952 gpm. Multiply 40 x 448.8 = 17,952 gallons per minute.
  5. Answer: 25.9 MGD. Divide 40 / 1.547 = 25.857, which rounds to 25.9 million gallons per day.
    Students who multiply instead of dividing get 61.9 and should be shown that a larger flow in cubic feet per second must give a larger number of million gallons per day, not a smaller one.
  6. Answer: 12 days. The drop is 812.0 - 806.0 = 6.0 feet, and 6.0 / 0.5 = 12 days.
  7. Answer: 6 days. The exception allows 1.0 foot per day, so 6.0 / 1.0 = 6 days.
  8. Answer: 15,640,848 gallons. One foot over 48 acres is 48 acre-feet, and 48 x 325,851 = 15,640,848 gallons. Accept 15.6 million gallons.
  9. Answer: 288 acre-feet. A 6.0-foot drop over 48 acres is 6.0 x 48 = 288 acre-feet.
  10. Answer: 17.32 psi. Multiply 40.0 x 0.433 = 17.32 pounds per square inch.
  11. Answer: Yes. Step 7 waives notice only when the release stays below 5 cubic feet per second, and 9 is above that, so the hatchery must be told at least 12 hours ahead.
  12. Answer: A flood watch means the reservoir may receive a large inflow soon, so the operator needs room in the pool to catch it. The slower rate is the normal rule because a fast drop can slump the reservoir banks and can strand fish along the shoreline, and those risks are worth accepting only when a flood is possible. Accept any response that names both the reason for hurrying and a reason the slow rate exists.

Differentiation

Support

Give these students the order with the two exception sentences already boxed, and a conversion strip listing each factor with an example of its use. Assign items 1, 2, 3, 4, 6, 8, and 11 as the core set, and let them attempt items 5, 9, and 10 after checking the core answers.

Extension

Ask these students to write Step 9 for the fictional order, covering what the operator does if the release must be stopped partway through because a downstream road washes out. The step must state one instruction, one exception, and one record to be kept, in the same voice as the rest of the order.

ELL supports

Pre-teach drawdown, gate, release, pool, and elevation with a labeled side-view sketch of a dam showing the pool surface at the order's stated elevations, the outlet gate, and the intake screen. Provide a two-column glossary of the conversion terms in English and the student's first language, and allow item 12 to be answered in a short list before it is written as sentences.

Extensions

Have students rewrite the fictional order as a one-page checklist an operator could carry, then compare the checklist with the original and write a paragraph on what the checklist format makes easy to miss. Dam and reservoir operations are staffed through several routes, including apprenticeship with a district, a two-year technical program, and engineering degrees, and students who found this reading satisfying can be pointed toward all three.