Upstream Boundary (Section V.1). 1. Delta boundary, daily inflow 2. Extend upstream channel by 45 miles, daily inflow 3. Hourly inflow at Freeport boundary.

Upstream Boundary

(Section V.1)

1. Delta boundary, daily inflow

2. Extend upstream channel by 45 miles, daily inflow

3. Hourly inflow at Freeport boundary

Walnut Grove

Sacramento

Rio Vista

Figure IV.1.1. Simulated stage at the upstream model boundary from three different formulations. Results are from Fischer Delta Model simulations of historical hydrology

3

5

7

9

11

13

15

17

8/4 8/19 9/3 9/18 10/3 10/18 11/2 11/17 12/2 12/17 1/11999

Sta

ge (

ft)

Case 1. Delta

Case 2. Delta extended 45 miles upstream

Case 3. Inflow BC at Frpt

Figure V.1-2. Simulated flow in Sacramento River at Freeport.

-7,500

-5,000

-2,500

0

2,500

5,000

7,500

10,000

12,500

15,000

17,500

10/24 10/25 10/26 10/27 10/28 10/29 10/30 10/31 11/1 11/2 11/3 11/4 11/5 11/6 11/71999

Flo

w (

cfs)

-6,000

-4,000

-2,000

0

2,000

4,000

6,000

8,000

10,000

12,000

14,000

Case 1. DeltaCase 3. Inflow BC at FrptDifference between Case 2. Delta extended 45 miles upstream and Case 1. DeltaDifference between Case 3. Inflow BC at Frpt and Case 1. Delta

a.

b.

a.

Difference (cfs)

b.

Figure V.1-5. Simulated combined flow into Delta Cross Channel and Georgiana Slough.

-10,000

-7,500

-5,000

-2,500

0

2,500

5,000

7,500

10,000

12,500

10/24 10/25 10/26 10/27 10/28 10/29 10/30 10/31 11/1 11/2 11/3 11/4 11/5 11/6 11/71999

Flo

w (

cfs)

-2,500

-1,250

0

1,250

2,500

3,750

5,000

6,250

7,500

8,750

Case 1. DeltaDifference between Case 2. Delta extended 45 miles upstream and Case 1. DeltaDifference between Case 3. Inflow BC at Frpt and Case 1. Delta

a.b.

a.

Difference (cfs)

b.

Positive flow is away from Sacramento River.

Observations – Upstream Boundary

• Current formulation may have significant stage error at Walnut Grove

• A 45 mile extension matches flow at Freeport reasonably well, even if only daily inflow is used