USGS Scientific Investigations Report 2010–5016 Development of an Environmental Flow Framework for the McKenzie River Basin, Oregon

Table 14. Median monthly streamflows for pre-dam, post-dam, computed unregulated, and simulated regulated conditions in reaches, McKenzie River, Oregon.

[Indicators of Hydrologic Alteration (IHA) significance count value: Output from the IHA software package and is equivalent to a p value for significance. Abbreviations: Unreg, computed unregulated flow time series from the U.S. Army Corps of Engineers; Reg, simulated regulated flow time series from the U.S. Army Corps of Engineers; na, not available]

Reach No.	Streamflow-gaging station No.	Period of record (water years)		Oct	Nov	Dec	Jan	Feb	Mar	Apr	May	June	July	Aug	Sept
Upper basin
1	14158850	Pre-dam	1936–1962	666	793	1,070	907	1,049	1,013	1,199	1,349	1,058	835	725	669
		Post-dam	1963–2008	665	805	1,049	1,083	1,103	1,112	1,113	1,244	990	802	692	655
		IHA significance count value		.99	.82	.90	.02	.48	.28	.34	.14	.38	.54	.48	.56
2	14159110	Pre-dam	1936–1962	1,732	2,062	2,790	2,361	2,668	2,637	3,120	3,342	2,652	2,162	1,886	1,740
		Post-dam	1963–2008	1,665	2,040	2,729	2,970	2,851	2,844	2,874	3,020	2,467	2,024	1,717	1,666
		IHA significance count value		.42	.82	.91	.00	.34	.35	.30	.15	.31	.36	.20	.40
Middle basin
3	14159500	Pre-dam	1936–1963	265	578	892	819	990	977	1,228	1,190	690	328	260	235
		Post-dam	1964–2008	918	1,045	1,080	1,020	332	316	388	817	593	420	752	804
		IHA significance count value		.00	.00	.03	.03	.08	.08	.08	.00	.39	.00	.00	.00
		Pre-dam	1936–1963	265	578	892	819	990	977	1,228	1,190	690	328	260	235
		Unreg	1964–2008	289	523	905	982	906	912	1,105	1,115	663	342	286	279
		IHA significance count value		.17	.82	1.00	.04	.34	.54	.11	.45	.92	.59	.05	.00
		Pre–dam	1936–1963	265	578	892	819	990	977	1,228	1,190	690	328	260	235
		Reg	1964–2004	792	1,282	1,310	1,310	300	300	488	1,074	737	484	613	652
		IHA significance count value		.00	.00	.05	.00	.16	.11	.01	.44	.46	.00	.00	.00
4	na	Pre-dam	1936–1962	2,004	2,569	3,630	3,139	3,735	3,655	4,521	4,619	3,270	2,515	2,185	2,023
		Post-dam	1963–2008	2,571	3,140	3,899	4,031	3,288	3,261	3,527	3,894	3,130	2,520	2,465	2,482
		IHA significance count value		.00	.00	.59	.00	.24	.16	.00	.05	.53	.95	.01	.00
5	14162200	Pre-dam	1936–1968	42	277	468	544	545	531	633	456	163	61	36	30
		Post-dam	1969–2008	257	510	598	672	65	192	232	303	167	149	406	232
		IHA significance count value		.00	.00	.11	.25	.01	.00	.02	.08	.80	.00	.00	.00
		Pre-dam	1936–1968	42	277	468	544	545	531	633	456	163	61	36	30
		Unreg	1969–2008	41	367	515	587	523	543	554	412	189	72	39	32
		IHA significance count value		.94	.14	.37	.76	.81	.92	.16	.24	.46	.13	.43	.48
		Pre–dam	1936–1968	42	277	468	544	545	531	633	456	163	61	36	30
		Reg	1969–2004	612	634	495	458	94	120	255	292	172	89	183	459
		IHA significance count value		.00	.00	.71	.67	.12	.01	.06	.06	.68	.00	.00	.00
6	na	Pre-dam	1925–1962	1,695	2,558	4,057	3,793	4,474	4,410	5,219	5,096	3,254	2,244	1,842	1,671
		Post-dam	1963–2008	2,493	3,646	4,699	5,336	3,722	3,788	3,850	4,075	3,161	2,460	2,558	2,450
		IHA significance count value		.00	.00	.21	.00	.20	.07	.00	.02	.68	.01	.00	.00
7	14162500	Pre-dam	1925–1962	1,730	2,610	4,140	3,870	4,565	4,500	5,325	5,200	3,320	2,290	1,880	1,705
		Post-dam	1963–2008	2,545	3,720	4,795	5,445	3,798	3,865	3,928	4,158	3,225	2,510	2,610	2,501
		IHA significance count value		.00	.00	.18	.00	.20	.09	.00	.01	.71	.00	.00	.00
		Pre-dam	1925–1962	1,730	2,610	4,140	3,870	4,565	4,500	5,325	5,200	3,320	2,290	1,880	1,705
		Unreg	1963–2004	1,753	2,964	4,160	4,883	4,577	4,510	5,098	4,788	3,320	2,230	1,896	1,710
		IHA significance count value		.22	.27	.42	.01	.93	.77	.22	.34	1.00	.36	.80	.14
		Pre-dam	1925–1962	1,730	2,610	4,140	3,870	4,565	4,500	5,325	5,200	3,320	2,290	1,880	1,705
		Reg	1963–2004	2,902	3,877	4,833	5,497	3,850	3,578	4,137	4,331	3,352	2,482	2,475	2,536
		IHA significance count value		.00	.00	.15	.00	.32	.01	.00	.04	.90	.02	.00	.00
8	14163150	Post-dam	1989–2008	1,055	1,902	3,230	3,877	2,213	2,475	2,103	2,630	1,353	1,040	1,039	1,033
Lower basin
9	na	Pre-dam	1925–1962	1,990	3,003	4,763	4,453	5,252	5,177	6,127	5,983	3,820	2,635	2,163	1,962
		Post-dam	1963–2008	2,927	4,280	5,517	6,265	4,369	4,447	4,520	4,784	3,711	2,888	3,003	2,877
		IHA significance count value		.00	.00	.18	.01	.22	.09	.00	.02	.71	.01	.00	.00
10	14163900	Post-dam	1989–2008	1,335	2,122	3,230	4,426	2,403	2,545	2,514	2,525	1,465	1,120	1,095	1,073
11	14164900	Pre-dam	1936–1962	1,710	3,086	5,284	4,977	6,324	5,698	6,239	5,474	3,291	2,001	1,660	1,527
		Post-dam	1963–2008	2,488	3,979	5,618	7,136	4,897	4,666	4,347	4,358	3,029	2,198	2,227	2,186
		IHA significance count value		.00	.04	.63	.01	.08	.03	.00	.02	.38	.01	.00	.00
12	14165500	Pre-dam	1936–1962	2,010	3,662	6,450	5,968	7,260	6,860	7,545	6,500	4,005	2,440	2,002	1,820
		Post-dam	1963–2008	2,880	4,682	6,563	8,590	5,661	5,920	5,209	5,130	3,612	2,690	2,705	2,623
		IHA significance count value		.00	.08	.94	.01	.11	.11	.00	.02	.32	.02	.00	.00