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Low-Flow Statistics for Selected Streams in New York, Excluding Long Island

Scientific Investigations Report 2024-5055
Prepared in cooperation with the New York State Department of Environmental Conservation
By: , , , , and 
https://doi.org/10.3133/sir20245055

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Acknowledgments

The authors would like to thank the New York State Department of Environmental Conservation for providing funding for this work. In addition, we would like to thank Rob Dudley, John Hammond, and Neil Terry of the U.S. Geological Survey for their detailed reviews of this manuscript and data release.

Abstract

The U.S. Geological Survey, in cooperation with the New York State Department of Environmental Conservation, updated low-streamflow statistics for New York, excluding Long Island and including hydrologically connected watersheds in bordering States, for the first time since 1972. Historical daily streamflow data for active and inactive gages were considered for this study with periods of record as recent as March 31, 2022, adding 50 years of data to the last published low-streamflow statistics report for New York and including 119 new gages where low-streamflow statistics are calculated for the first time. Gages were evaluated across several criteria to identify gages that were not suitable for low-streamflow frequency analysis. In addition, gages were evaluated for the presence of alteration within the streamflow period of record based on previous studies and U.S. Geological Survey National Water Information System site metadata including peak flow codes.

A trend analysis was performed using the Wilcoxon rank-sum hypothesis test comparing data from the most recent 30 years of record to data from 30 years and earlier for each long-record gage (30 years or more of available data). Results from the trend analysis indicated that 45 unaltered and 32 altered long-record sites had a statistically significant trend for the annual minimum n-day time series; most gages showed increasing trends in the annual minimum n-day time series. Low-streamflow statistics were calculated using the most recent 30 years of record for gages with a statistically significant trend. Before and after 1972, the lowest annual 7-day and 30-day average streamflow that occurs (on average) once every 10 years (7Q10 and 30Q10 statistics respectively) increased significantly at 41 unaltered gages and decreased significantly at 3 unaltered gages where data were available.

Introduction

Reliable information about the magnitude, frequency, and duration of low streamflow is critical for water-supply management; reservoir design; waste-load allocation; and the preservation of water quality and quantity for irrigation, recreation, and ecological conservation purposes. Low-streamflow frequency and duration information are particularly important in regions and States that are periodically affected by drought, including New York. As part of their mission to protect public health and aquatic ecosystems, State agencies such as the New York State Department of Environmental Conservation (NYSDEC) need accurate and representative low-streamflow statistics to establish realistic and applicable criteria for both water quality and water quantity (NYSDEC, [1998]). For example, low-streamflow statistics, such as the lowest annual 7-day or 30-day average streamflow that occurs (on average) once every 10 years (7Q10 or 30Q10, respectively), have been used by NYSDEC water-resource managers and planners as a threshold criterion for applying for regulatory measures affecting chronic aquatic life (for which 7Q10 data are used) or chronic human health (for which 30Q10 data are used). These statistics are further used by NYSDEC to regulate waste-load allocations for point sources and total maximum daily loads for streams (NYSDEC, [1998]). To that end, the U.S. Geological Survey calculated low-streamflow statistics of New York with the NYSDEC.

Given the importance of these applications, it is critical to effectively measure and document low-streamflow data for characterizing low-streamflow frequency relations on a regular basis, preferably every 10 years, and especially after periods of extremely low streamflow (Feaster and Lee, 2017; Farmer and others, 2019). Recent droughts (2016, 2020, and 2022) in New York (U.S. Drought Monitor, 2023) have heightened the need for pertinent low-streamflow information for State and local agencies to make critical water-resources decisions. Low-streamflow statistics in New York have not been updated statewide since 1972 (Eissler, 1978), and low-streamflow characteristics in New York may have been changing since that time (Suro and Gazoorian, 2011; Dudley and others, 2020). The objective of this study was to compute new 7Q10 and 30Q10 low-streamflow statistics for New York (excluding Long Island) and hydrologically connected watersheds in bordering States.

Study Area and Gage Selection

The study area consists of the State of New York and hydrologically connected streams from bordering States of Pennsylvania, New Jersey, Connecticut, Massachusetts, and Vermont (fig. 1). Site-specific metadata and daily average streamflow data were accessed using the R package dataRetrieval (R Core Team, 2020; De Cicco and others, [2014]) from the U.S. Geological Survey (USGS) National Water Information System (NWIS) database (USGS, 2016) for 684 active or discontinued gages across New York, and an additional 79 gages from bordering States. A total of 763 gages with daily average streamflow data were available in the study area. Based on the gage-selection criteria described throughout this section, 394 gages met all gage-selection criteria.

First, 29 Long Island gages were removed from this study because Long Island has unique hydrologic characteristics and those gages are affected by varying degrees of urbanization and regulation (Glas and others, 2023). Accurate low-streamflow statistics for Long Island would require additional analysis beyond the scope of this study.

Second, 270 gages with less than 10 years, or 3,652 days, of available daily streamflow records were removed from the study. Typically, low-streamflow statistics are computed for streams when at least 10 years of continuous daily record are available (Lukasz, 2021; Williams-Sether, 2021; Hammond and others, 2022a). However, statistics computed from longer-term records (typically 30 years or more of available data) are preferred because they are likely to be more representative of a broader range of hydrologic conditions. Thus, long-term streamflow data are better suited for trend assessments, but to be more inclusive of available data, gages with at least 10 years of data were included in this study.

Third, 29 gages had more than 20 percent of the period of record missing. Missing data is a common problem in hydrologic data analysis and there are several existing methods and guidance frameworks established for filling in or developing procedures to remove missing data (Gustard and Demuth, 2008). However, this study took a conservative approach in not estimating missing daily streamflow records. Based on Gustard and Demuth (2008), a threshold of 20 percent of missing days in the streamflow record was used to consider the record incomplete and exclude gages from the study.

Fourth, 94 gages had records with days of zero streamflow and would therefore not be suitable to calculate low-streamflow statistics because log transformations are required to calculate 7Q10 and 30Q10. An exception was made for the Housatonic River at Stevenson, Conn. (station 01205500) gage which has a long period of record that includes one day with a recorded zero streamflow near the beginning of the period of record. The zero-streamflow observation for this gage was considered an outlier in magnitude when compared with the entire period of record, so to avoid disqualifying this record entirely, the time series was truncated to remove the zero-streamflow observation. Although including gages with observed zero-streamflow measurements is outside the scope of this study, an avenue for potential further study would include performing a logistic regression to better understand the probability of zero-streamflow observations occurring within these basins.

Fifth, nine gages were discontinued, where all recorded data were transferred to a nearby new gage. Novak (1985) indicated that two discharge records could be considered equivalent if they are on the same stream and there is less than a 5 percent difference in drainage area between the gages or differences in monthly discharge between the two gages could be expected to be less than 5 percent. These nine gages were not included in the study to avoid double counting their record.

Sixth, 16 gages were removed due to having less than 10 recorded climatic years. Low-streamflow metrics were computed on a climatic-year basis. A climatic year is a continuous 12-month period selected for the presentation of data relative to a hydrological or meteorological phenomenon of interest and is usually designated by the year of the first month in the 12-month period (Langbein and Iseri, 1960). In the Northeast, streamflow is typically lowest during the late summer months and highest during the earlier spring months, thus the climatic year from April 1 to March 31 was used for low-streamflow frequency analysis to increase the likelihood that the lowest streamflow values were captured within each climatic year.

In total, 369 gages were removed from this study given the gage-selection criteria (numerous gages met multiple removal criteria), and 394 gages remain for further analysis; this reflects an additional 119 gages analyzed since low-streamflow statistics were last calculated in 1972 (Eissler, 1978).

Developing models to estimate low-streamflow statistics for ungaged locations is difficult where streamflow has been altered by human influence and not reflected by natural basin characteristics, which are the primary predictors used to create a model. Therefore, the gages meeting selection criteria for this study were classified into two groups: 181 altered and 213 unaltered gages (fig. 1), where all historical data available were obtained up to March 31, 2022. Altered gages have documented alterations of observed daily streamflow due to human-related water use and management such as reservoir operations, surface water or groundwater withdrawals, diversions, engineered drainage systems, and impervious areas from urban development. For this analysis, altered gages were determined from previous work by Suro and Gazoorian (2011), and analysis of remark comments in the water-year summaries of individual gages on the USGS Water Data for the Nation website (U.S. Geological Survey, 2016) by flagging words associated with alteration (for example, “regulation,” “pumping,” and “diversion”). All gages classified as unaltered were compared with gage lists and regulation designations from statewide flood-frequency studies (Wall and others, 2014; Lumia and others, 2006) to determine whether peak streamflow values at the gage have been affected by some degree of regulation or diversion (specifically, peak streamflow codes 5 and 6; https://nwis.waterdata.usgs.gov/nwis/peak?help). In addition, all gages were evaluated for alteration by analyzing satellite imagery for the presence of upstream dams or other visible signs of alteration (for example, power plants or wastewater facilities) and by considering site information provided in databases including the Geospatial Attributes of Gages for Evaluating Streamflow, version II (GAGES-II; Falcone, 2011).

Altered and unaltered streamgages are distributed throughout the study area
Figure 1.

Map showing the 213 unaltered and 181 altered gages with daily streamflow evaluated for this study in New York and adjacent States.

Methods for Calculating At-Site Low-Streamflow Statistics

The most common low-streamflow statistics used by organizations across the United States to inform decisions during low-streamflow periods are calculated using a moving average across a standard interval (typically a 7-day or 30-day period) of the daily average streamflow values (U.S. Environmental Protection Agency, 1986; Smakhtin, 2001). Low-streamflow statistics calculated using the moving average n-day values are representative of persistent low-streamflow periods within the daily streamflow record. The moving average 7-day and 30-day streamflow time series were calculated using daily average streamflow data available across all gages for this study, and the annual minimum 7-day and 30-day values were determined for each climatic year across the period of record.

Data Handling for Missing and Irregular Streamflow Values

Missing data within a daily streamflow time series are a persistent problem for hydrologic frequency analysis (Gustard and Demuth, 2008). Missing data can be present within a USGS daily streamflow time series for multiple reasons. For example, the gage may have only operated on a seasonal basis, the intention of the gage may have only been to measure a limited range of streamflow, or the gage may have been temporarily discontinued due to equipment failure, lost funding, or other related issues (Novak, 1985). For this study, missing daily streamflow data were classified as not available directly within the raw data time series obtained from NWIS. In addition, a streamflow value was classified as not available if a date or multiple dates were missing from the raw data time series obtained from NWIS, and the missing dates were added to the time series to create a set of continuous dates for all gages. Missing daily data and irregular timing of low streamflow (for example, lowest streamflow values occur during typical high-streamflow months) were flagged to determine if an individual climatic year should be removed if the data met any of the following criteria:

  • • The low-streamflow months of July, August, September, and October included any missing daily values.

  • • The annual minimum n-day value included missing daily values within the moving average n-day period.

  • • The annual minimum n-day value was within the first 7 or 30 days of April (the beginning of the climatic year), and the moving average window included daily data from the previous climatic year.

The annual minimum 7-day and 30-day time series for unaltered gages did not include any gages with missing daily data within any annual minimum n-day moving average values across all climatic years. The altered gages included 12 gages where at least one annual minimum 7-day (5 gages) or 30-day (7 gages) value for a climatic year includes at least one missing value within the moving average window; a climatic year meeting this criterion was removed from the period of record.

Figure 2 is a histogram of the month that the annual minimum 7-day values occurred for each climatic year across the period of record for all unaltered gages. The unaltered gages were used to determine the low-streamflow months because they are the most representative of natural climatic conditions within the study area. As expected, the annual minimum 7-day values occurred most often during July, August, September, and October. At least 1 climatic year was removed for 13 unaltered and 22 altered gages that had missing daily data during the low-streamflow months.

Most values occur in August and September, with about half as many in July and October. Few occur in any other months
Figure 2.

Graph showing the total number of occurrences of the annual minimum 7-day values within each month for all available data across unaltered gages in New York, excluding Long Island, that were included in this study.

Any annual minimum n-day time series that spanned the end of one climatic year and the start of the next (March 31 to April 1) were not included in the annual minimum time series for a gage. The unaltered gages included 12 where at least 1 climatic year was removed for annual minimum 7-day (3 gages) or 30-day (9 gages) values near the start of a climatic year. Unaltered gages typically would not have annual minimum n-day values during the high-streamflow months. These gages were further evaluated, and it was determined that these values were high outliers when compared with the annual minimum values across the period of record.

The altered gages included 82 where at least 1 climatic year was removed for annual minimum 7-day (31 gages) and 30-day (51 gages) values near the start of a climatic year. Altered or minimally altered gages are more likely to include annual minimum streamflow values near the start of the climatic year during typically high-streamflow months because the observed streamflow may be consistent with the alteration patterns of a specific gage where the lowest streamflow values occur during the high-streamflow months (for example, station 01357499 is a diversion channel for the Erie Canal, where the locks are closed during the winter; the streamflow of station 01325000 is regulated by the Conklingville Dam, where the lowest streamflow values typically occur during the winter months).

The same climatic years were removed for the annual minimum 7-day and 30-day time series to ensure that the same years were used to calculate the 7Q10 and 30Q10 statistics for any gage to avoid a mismatch in the climatic years used to calculate each low-streamflow statistic. In total, 20 unaltered and 69 altered gages have at least 1 climatic year removed from the annual minimum 7-day and 30-day time series because of missing data during the low-streamflow months, missing daily data within the annual minimum n-day moving average window, or annual minimum n-day values near the start of the climatic year. Across all 213 unaltered and 181 altered gages, a total of 32 and 363 climatic years, respectively, were removed given the criteria listed in this section.

Trend Analysis

Recent studies have documented changes in precipitation patterns across the Northeast, and the need to account for trends in hydrologic frequency analysis to calculate accurate low-streamflow statistics (Dethier and others, 2020; Dudley and others, 2020; Hammond and others, 2022b). McCabe and Wolock (2021) investigated drought and pluvial periods using a simple water balance model across the conterminous United States from 1900 through 2014. Across most of the conterminous United States and in the Northeast, most severe drought events occurred before 1970 and the region has been in a sustained pluvial period for the last 50 years (McCabe and Wolock, 2021). In addition, Seager and others (2012) study precipitation patterns in the Catskill Mountains region and determined that a severe drought occurred during the mid-1960s, followed by a wet period that continues through the end of their study period (2007). Affecting most of the Northeast, the severe 1960s drought created long-lasting water supply issues and shaped future water policy across the region (Barksdale, 1968).

Blum and others (2019) and Vogel and Kroll (2020) find that using a recent subset of the period of record for frequency analysis improves the accuracy of low-streamflow frequency statistics when nonstationary conditions are observed. Blum and others (2019) use Monte Carlo simulation experiments with monotonic trends observed at gages in the Chesapeake Bay watershed and observe that, when a statistically significant trend in low streamflow was present, the best estimate of the 7Q10 statistic was more accurately computed using the most recent 30 years of historical record. Blum and others (2019) suggest a simple adaptive framework for computing 7Q10: use the most recent 30 years of the record when a statistically significant (α) trend was detected (at α≤0.1) or use the full historical record.

Similar to the adaptive method developed by Blum and others (2019), this study used the Wilcoxon rank-sum hypothesis test to determine whether data from the most recent 30 years of record are statistically different from data from 30 years ago and earlier. The Mann-Kendall trend test was explored for this study but was ultimately not used because data gaps are included within the annual minimum n-day (7-day or 30-day values) datasets and this trend test requires little to no missing data to provide an accurate test result (Helsel and others, 2020). In addition, the two-sample t-test was explored for this study, but the log-transformed annual minimum n-day time series for each group appeared abnormal for most gages. The nonparametric two-sample Wilcoxon rank-sum hypothesis test compares two groups without any prior knowledge that either group would be higher or lower than one another (Helsel and others, 2020). The null hypothesis for this study states that the annual minimum n-day streamflow values from the most recent 30 years of available data come from the same distributions as data from 30 years and earlier within the period of record. A less stringent α=0.1 was used for this study to determine statistical significance of the hypothesis test.

Low-Streamflow Frequency Analysis

The low-streamflow statistics for 7Q10 and 30Q10 were calculated using the annual minimum 7-day and 30-day moving average of the daily average values for each climatic year across the available period of record for each gage. The Wilcoxon rank-sum hypothesis test results were used to determine which set of years were used to calculate the statistics, and then the annual minimum 7-day and 30-day time series were fit to a probability distribution to calculate the streamflow value associated with a specific probability of nonexceedance. The log-Pearson type III probability distribution was used to fit the n-day low-streamflow values for the low-streamflow frequency analysis (Bhatti and others, 2019). The log-Pearson type III distribution has been widely used to model low- and peak-streamflow statistics throughout the country (England and others, 2019; Helsel and others, 2020). The log-Pearson type III distribution of the n-day time series to determine the streamflow of the 10-year recurrence interval (Q10) is defined as:

ln ⁡ Q 10 = µ y + K 10 σ y
,
(1)
where

µy

is the log-space mean, and

σy

is the log-space standard deviation of the n-day time series.

K10 is a frequency factor approximated by the Wilson-Hilferty transformation, which is a function of the nominal skew G (Kirby, 1972) defined as:

G = n ∑ i = 1 n Y i - µ y 3 n - 1 n - 2 σ y 3
,
(2)
and
K 10 G = 2 G 1 + G Z 10 6 - G 2 36 3 - 2 G
,
(3)
where

n

is the number of climatic years,

Yi

is the log-transformed annual minimum n-day value for a specific climatic year (i), and

Z10

is the 10th percentile from the standard normal distribution.

Low-Streamflow Nonexceedance Frequency Analysis

The nonexceedance probability tables were determined for the daily moving average 7-day and 30-day values for the 102 altered gages determined not to be suitable for low-streamflow frequency analysis (Stagnitta and others, 2024). The nonexceedance probabilities of the n-day average time series were determined using Weibull’s plotting position to rank the daily n-day average streamflow values constructing an empirical cumulative distribution (Langbein and Iseri, 1960). These nonexceedance percentiles should not be construed to be a representation of a low-streamflow frequency, but as an empirical representation of recorded n-day average streamflow values.

Results

Low-streamflow frequency analysis requires detailed methods to account for missing data or trends to ensure that low-streamflow statistics are accurately calculated to represent current conditions. Results from the trend analysis are detailed in the following section, including a comparison of 7Q10 values calculated pre- and post-1972.

Trend Analysis

Low-streamflow statistics for New York State were last calculated using data from 1972 and earlier (Eissler, 1978). The comparison of the 7Q10 values for 91 long-record (30 years or more of available data) unaltered gages where data were available pre- and post-1972 is shown in figure 3. Across 83 of the 91 gages, 7Q10 values have increased since 1972, with the largest changes occurring in the western, Catskill, and Adirondack regions of the State. Of the 83 unaltered sites with an increase, 41 of the increases were statistically significant (α≤0.1) and averaged 46 and 48 percent for the 7Q10 and 30Q10 values, respectively. Of the 8 unaltered sites with a decrease, 3 of the decreases were statistically significant (α≤0.1) and averaged 9 and 8 percent for the 7Q10 and 30Q10 values, respectively.

Of the 213 unaltered gages, 121 gages had at least 30 years of available data and were evaluated for nonstationarity. The null hypothesis was rejected for 45 unaltered gages at α=0.1 significance level and the most recent 30 years of available data were used to calculate low-streamflow statistics for these gages. The remaining 76 unaltered gages failed to reject the null hypothesis, and the entire period of record was used to calculate low-streamflow statistics. In addition, for the remaining 92 unaltered gages where no hypothesis testing was performed, the entire period of record was used to calculate low-streamflow statistics because these gages had less than 30 years of available data.

The annual minimum 7-day time series for all altered gages were visually inspected to determine whether there was an irregular change in the annual minimum values and whether the overall trend displayed was inconsistent with the underlying natural condition of increasing low-streamflow values in the study area (fig. 3; for example, the annual minimum values showed an irregular pattern due to inconsistent surface water withdrawals near the gage). Of the 181 altered gages inspected, 79 displayed consistent trends of the annual minimum 7-day time series and were suitable for low-streamflow frequency analysis. Of the 79, 73 had at least 30 years of available data and were evaluated for nonstationarity. The null hypothesis was rejected for 32 altered gages at α=0.1 and the most recent 30 years of available data were used to calculate low-streamflow statistics. The remaining 41 altered gages failed to reject the null hypothesis, and the entire period of record was used to calculate low-streamflow statistics. In addition, for the remaining six altered gages where no trend analysis was performed, the entire period of record was used to calculate low-streamflow statistics because these gages had fewer than 30 years of available data.

For gages that exhibited different hypothesis test results for trends in the annual minimum 7-day and 30-day time series, the entire period of record was used to calculate low-streamflow statistics and the same set of years were used for each n-day time series.

Most streamgage 7Q10 values have increased since 1972 across the study area, although most changed by less than 75%
Figure 3.

Map showing a comparison of the lowest annual 7-day average streamflow that occurs (on average) once every 10 years (7Q10) values for 91 long-record (30 years or more of available data) unaltered gages with data available pre- and post-1972. 7Q10 values were calculated with data from before 1972 and data available from the entirety or a subset of the period of record depending on results from Wilcoxon rank-sum hypothesis test. Gages where 7Q10 increased from pre-1972 data are marked with an upward blue triangle. Gages where 7Q10 decreased from pre-1972 data are marked with a downward red triangle. The size of the triangle corresponds to the positive or negative percent change from pre-1972 7Q10 versus 7Q10 calculated for this study. Gages marked with a filled triangle indicate that no significant trend (α>0.1) was found at the gage. >, Greater than; <, less than.

Low-Streamflow Frequency Analysis

Stagnitta and others (2024) and table 1.1, located in appendix 1, include the 7Q10 and 30Q10 values calculated for all 213 unaltered and 79 altered gages.

Discussion

Methods for handling missing and irregular data ensure accurate and consistent streamflow values are included to calculate low-streamflow statistics that best represent low-streamflow conditions observed within the study area. This analysis provides methods to flag and remove outlier annual minimum n-day values from the low-streamflow time series. Most climatic years were included across all gages for this study, where only 20 unaltered and 69 altered gages were flagged to remove at least 1 climatic year from the period of record.

A trend analysis of the annual minimum n-day values ensures that the low-streamflow frequency analysis using historical annual values represents current conditions observed within the stream. Performing a low-streamflow frequency analysis may not yield the most accurate and least biased estimate of current n-day low streamflow when there are statistically significant trends in the data. More than half of the gages had long records (30 years or more of available data), where 45 unaltered and 32 altered gages had a statistically significant trend in the data, and the most recent 30 years of available data were used to calculate low-streamflow statistics.

The rise in values of low-streamflow statistics statewide is consistent with findings from other studies across the Northeast and may be attributed to increased precipitation across the region for much of the last 50 years (McCabe and Wolock, 2021; Seager and others, 2012). Further analysis is needed to understand the drivers and covariates of trends in low streamflow across New York. A trend analysis of low-streamflow statistics along with precipitation, groundwater storage, anthropogenic variables, and other variables of interest is needed to better understand the causes of changes to low streamflow at both unaltered and altered gages across the State and is beyond the scope of this study. Such work would help better define the selection of period of record for computing low-streamflow statistics. For example, selecting a period of record that begins with the advent of a dam, diversion, or step change in precipitation may present different results. Record extension for unaltered gages was initially explored for this study but was not pursued to permit the potential for further research using the low-streamflow statistics.

Summary

The U.S. Geological Survey updated low-streamflow statistics in New York with the cooperation of the New York Department of Environmental Conservation. Low-streamflow statistics are used for several applications including wastewater permitting, withdrawal permitting, determining total maximum daily loads, setting in-stream flow criteria to protect aquatic life, and drought monitoring. Using streamflow data available through the U.S. Geological Survey National Water Information System, the low-streamflow statistics, such as the lowest annual 7-day average streamflow that occurs (on average) once every 10 years (7Q10 and 30Q10, respectively), were calculated for 213 unaltered and 79 altered gages. Nonexceedance probabilities for the daily moving average 7-day and 30-day values were calculated for the remaining 102 altered gages that were not suitable for low-streamflow frequency analysis.

Three categories of situations resulted in missing or irregular daily data and the removal of a climatic year from the period of record for selected gages: missing daily data within the low-streamflow months of July, August, September, and October; missing daily data within the moving average window for an annual minimum 7-day or 30-day value; and an annual minimum 7-day or 30-day value, where the moving average spans the end of one and start of the next climatic year. A trend analysis was performed to account for nonstationarity present within the period of record for long-record sites. A hypothesis test using the Wilcoxon rank-sum hypothesis test was used to compare data from the most recent 30 years of record to data from 30 years ago and earlier to determine whether there was a statistically significant trend. Statistically significant trends (α≤0.1) were observed for 45 unaltered and 32 altered gages; data from the most recent 30 years of record were used to calculate low-streamflow statistics for these gages. The remaining unaltered and altered gages used the entire period of record to calculate low-streamflow statistics.

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Appendix 1. Low-Streamflow Statistics for 213 Unaltered and 79 Altered Gages

Table 1.1.    

Low-streamflow statistics for the lowest annual 7-day and 30-day average streamflow that occurs (on average) once every 10 years (7Q10 or 30Q10, respectively) for 213 unaltered and 79 altered gages.

[Data from Stagnitta and others (2024). The calculated nonexceedance probabilities column refers to altered sites where no low-streamflow statistics were calculated and the tables of daily nonexceedance probabilities are available in Stagnitta and others (2024). Station names appear as listed in the U.S. Geological Survey National Water Information System (U.S. Geological Survey, 2016). CT, Connecticut; MA, Massachusetts; NJ, New Jersey; NY, New York; PA, Pennsylvania; Ave., avenue; Bl, below; Blw, below; Blvd, boulevard; Bk, brook; Br, branch; Cr, creek; E, east; L, lake; Nr, near; R, river; Rd, road; St., street; St., Saint; Trib, tributary; W, West; @, at; mi2, square mile; H0, null hypothesis; α, significance level; ≤, less than or equal to; Q, discharge; ft3/s, cubic foot per second; —, not calculated]
Site number Station name Drainage area (mi2) Altered gage Calculated nonexceedance probabilities Total length of available record (years) Is the H0 rejected with a α≤0.1? Length of record after trend analysis (years) Climate years used to calculate low-streamflow statistics 7Q10 (ft3/s) 30Q10 (ft3/s)
01197500 Housatonic River Near Great Barrington, MA 282.00 Yes No 108 No 108 1915–2022 67.357 87.401
01198000 Green River Near Great Barrington, MA 51.00 No No 35 No 35 1953–1971, 1995–1996, 2009–2022 3.279 3.883
01198125 Housatonic River Near Ashley Falls, MA 465.00 No No 16 Less than 30 years of data 16 1995–1996, 2009–2022 76.530 91.992
01199000 Housatonic River At Falls Village, CT 634.00 Yes No 109 No 109 1914–2022 108.450 143.789
01199050 Salmon Creek At Lime Rock, CT 29.40 No No 59 No 59 1963–2021 3.364 4.669
01200000 Tenmile River Near Gaylordsville, CT 203.00 Yes No 85 No 85 1932–1989, 1993–1999, 2002–2021 12.645 16.761
01200500 Housatonic River At Gaylordsville, CT 996.00 Yes No 81 No 81 1942–2022 153.718 195.817
01201487 Still River At Route 7 At Brookfield Center, CT 62.30 Yes Yes — — — — — —
01201500 Still R Nr Lanesville, CT 67.50 Yes No 34 Yes 30 1937–1966 15.073 18.775
01205500 Housatonic River At Stevenson, CT 1,544.00 Yes No 91 No 91 1932–2022 138.899 267.236
01208990 Saugatuck River Near Redding, CT 21.00 No No 57 No 57 1966–2022 0.314 0.552
01209700 Norwalk River At South Wilton, CT 30.00 No No 59 No 59 1964–2022 1.681 2.401
01209901 Rippowam River At Stamford, CT 34.00 Yes Yes — — — — — —
01212500 Byram River At Pemberwick, CT 25.60 No No 10 Less than 30 years of data 10 2011–2020 0.305 0.846
01300000 Blind Brook At Rye NY 9.31 No No 44 No 44 1946–1989 0.522 0.901
01301000 Mamaroneck River At Mamaroneck NY 22.60 No No 41 Yes 30 1960–1989 0.533 1.146
01301500 Hutchinson River At Pelham NY 5.78 No No 47 No 47 1946–1989, 2011–2013 0.072 0.243
01302000 Bronx River At Bronxville NY 43.90 Yes No 44 Yes 30 1960–1989 4.550 7.046
01302020 Bronx River At Ny Botanical Garden At Bronx NY 38.40 Yes Yes — — — — — —
01312000 Hudson River Near Newcomb NY 192.00 No No 78 Yes 30 1976–1982, 1984–1987, 2004–2022 34.064 52.099
01313500 Cedar R Below Chain Lakes Nr Indian Lake NY 160.00 No No 28 Less than 30 years of data 28 1933–1940, 1942–1961 23.049 32.051
01314000 Hudson R At Gooley, Near Indian Lake NY 419.00 No No 50 No 50 1918–1940, 1942–1968 56.064 71.874
01315000 Indian River Near Indian Lake NY 132.00 Yes Yes — — — — — —
01315500 Hudson River At North Creek NY 792.00 Yes No 112 No 112 1909–1940, 1942–2015, 2017–2022 215.082 279.016
01317000 Schroon River At Riverbank NY 527.00 No No 42 Yes 30 1939–1940, 1942–1966, 1968–1970 48.871 65.714
01318500 Hudson River At Hadley NY 1,664.00 Yes Yes — — — — — —
01319000 East Branch Sacandaga River At Griffin NY 1,14.00 No No 44 No 44 1935–1978 4.032 6.567
01321000 Sacandaga River Near Hope NY 491.00 Yes No 110 No 110 1913–2022 43.361 63.583
01325000 Sacandaga River At Stewarts Bridge Nr Hadley NY 1,055.00 Yes Yes — — — — — —
01326500 Hudson River At Spier Falls NY 2,779.00 No No 10 Less than 30 years of data 10 1914–1923 945.416 1,113.425
01327750 Hudson River At Fort Edward NY 2,810.00 Yes Yes — — — — — —
01328000 Bond Creek At Dunham Basin NY 14.10 Yes No 34 No 34 1949–1982 0.451 0.732
01329000 Batten Kill At Arlington, VT 152.00 No No 55 No 55 1930–1984 51.780 61.524
01329490 Batten Kill Below Mill At Battenville NY 396.00 No No 69 No 69 1924–1968, 1999–2022 78.067 94.639
01330000 Glowegee Creek At West Milton NY 24.90 No No 45 Yes 30 1993–2022 2.265 3.750
01330500 Kayaderosseras Creek Nr West Milton NY 84.20 No No 67 Yes 30 1966–1995 18.739 24.215
01331095 Hudson River At Stillwater NY 3,773.00 Yes Yes — — — — — —
01331500 Hoosic River At Adams, MA 46.70 No No 90 No 90 1933–2022 12.582 15.500
01332000 North Branch Hoosic River At North Adams, MA 40.90 No No 58 No 58 1933–1990 5.227 6.978
01332500 Hoosic River Near Williamstown, MA 126.00 No No 81 No 81 1942–2022 39.003 48.068
01333000 Green River At Williamstown, MA 42.60 No No 72 No 72 1951–2022 4.800 6.265
01333500 Little Hoosic River At Petersburg NY 56.10 No No 44 Yes 30 1967–1996 4.364 5.307
01334000 Walloomsac River Near North Bennington, VT 111.00 No No 90 No 90 1933–2022 32.629 40.565
01334500 Hoosic River Near Eagle Bridge NY 510.00 Yes Yes — — — — — —
01335500 Hudson River At Mechanicville NY 4,500.00 Yes Yes — — — — — —
01335754 Hudson River Above Lock 1 Near Waterford NY 4,605.00 Yes Yes — — — — — —
01336000 Mohawk River Below Delta Dam Near Rome NY 152.00 Yes Yes — — — — — —
01343060 West Canada Creek Near Wilmurt NY 238.00 No No 20 Less than 30 years of data 20 2003–2022 48.049 68.881
01344000 West Canada Creek At Hinckley NY 375.00 Yes Yes — — — — — —
01346000 West Canada Creek At Kast Bridge NY 560.00 Yes No 103 Yes 30 1993–2022 300.439 367.303
01347000 Mohawk River Near Little Falls NY 1,342.00 Yes No 94 Yes 30 1993–2022 632.447 740.510
01347500 East Canada Creek At Dolgeville NY 258.00 No No 31 No 31 1900–1912, 1929–1946 53.898 72.375
01348000 East Canada Creek At East Creek NY 289.00 Yes No 56 No 56 1947–1995, 2016–2022 14.798 58.279
01349000 Otsquago Creek At Fort Plain NY 61.00 No No 46 No 46 1951–1989, 2016–2022 2.694 3.536
01349150 Canajoharie Creek Near Canajoharie NY 59.70 No No 29 Less than 30 years of data 29 1994–2022 0.976 1.758
01349700 East Kill Near Jewett Center NY 35.60 No No 25 Less than 30 years of data 25 1998–2022 1.496 2.105
01349705 Schoharie Creek Near Lexington NY 96.80 No No 22 Less than 30 years of data 22 2001–2022 7.967 11.150
01349711 West Kill Below Hunter Brook Near Spruceton NY 4.97 No No 24 Less than 30 years of data 24 1999–2022 0.631 0.792
01349810 West Kill Near West Kill NY 27.00 No No 24 Less than 30 years of data 24 1999–2022 2.104 2.761
01349840 Batavia Kill Near Maplecrest NY 2.03 No No 11 Less than 30 years of data 11 1999–2009 0.210 0.299
01349950 Batavia Kill At Red Falls Near Prattsville NY 68.60 No No 24 Less than 30 years of data 24 1999–2022 2.534 3.590
01350000 Schoharie Creek At Prattsville NY 237.00 No No 117 Yes 30 1993–2022 12.919 16.031
01350035 Bear Kill Near Prattsville NY 25.70 No No 23 Less than 30 years of data 23 2000–2022 0.314 0.602
01350080 Manor Kill At West Conesville Near Gilboa NY 32.40 No No 35 No 35 1988–2022 1.690 1.967
01350120 Platter Kill At Gilboa NY 10.90 No No 47 No 47 1976–2022 1.098 1.292
01350140 Mine Kill Near North Blenheim NY 16.20 No No 47 Yes 30 1993–2022 0.292 0.509
01350355 Schoharie Creek At Breakabeen NY 444.00 Yes Yes — — — — — —
01350500 Schoharie Creek At Middleburgh NY 534.00 Yes Yes — — — — — —
01351000 Fox Creek At West Berne NY 67.20 No No 12 Less than 30 years of data 12 1926–1932, 1964–1968 0.192 0.374
01351500 Schoharie Creek At Burtonsville NY 886.00 Yes No 82 Yes 30 1993–2022 14.725 19.185
01354500 Mohawk River At Freeman's Bridge At Schenectady NY 3,310.00 Yes Yes — — — — — —
01356190 Lisha Kill Northwest Of Niskayuna NY 16.20 No No 14 Less than 30 years of data 14 1995–1997, 2002–2012 0.258 0.867
01357499 Mohawk River Diversion To Power Plant At Crescent Dam NY — Yes Yes — — — — — —
01357500 Mohawk River At Cohoes NY 3,450.00 Yes No 104 No 104 1919–2022 612.572 784.144
01358000 Hudson River At Green Island NY 8,090.00 Yes No 72 No 72 1947–1997, 2002–2022 2,828.804 3,325.255
01358500 Poesten Kill Near Troy NY 89.40 Yes No 44 No 44 1925–1968 2.787 4.984
01359519 Normans Kill Near Westmere NY 136.00 Yes Yes — — — — — —
01359750 Moordener Kill At Castleton–On–Hudson NY 31.60 No No 37 No 37 1959–1995 2.366 2.863
01360640 Valatie Kill Near Nassau NY 9.48 No No 31 No 31 1992–2022 0.165 0.309
01361000 Kinderhook Creek At Rossman NY 329.00 No No 52 Yes 30 1949–1968, 2013–2022 13.944 20.310
013621955 Birch Creek At Big Indian NY 12.50 No No 23 Less than 30 years of data 23 2000–2022 2.281 2.729
01362200 Esopus Creek At Allaben NY 63.70 No No 58 Yes 30 1993–2022 7.089 8.918
01362230 Diversion From Schoharie Reservoir NY — Yes Yes — — — — — —
0136230002 Woodland Creek Above Mouth At Phoenicia NY 20.60 No No 18 Less than 30 years of data 18 2005–2022 2.985 4.149
01362342 Hollow Tree Brook At Lanesville NY 1.95 No No 24 Less than 30 years of data 24 1999–2022 0.349 0.461
01362370 Stony Clove Creek Blw Ox Clove At Chichester NY 30.90 No No 25 Less than 30 years of data 25 1998–2022 4.948 5.756
01362487 Beaver Kill At Mount Tremper NY 25.00 No No 11 Less than 30 years of data 11 2012–2022 1.376 2.011
01362497 Little Beaver Kill At Beechford Near Mt Tremper NY 16.50 No No 24 Less than 30 years of data 24 1999–2022 0.496 0.885
01362500 Esopus Creek At Coldbrook NY 192.00 Yes Yes — — — — — —
01363382 Bush Kill Blw Maltby Hollow Bk At West Shokan NY 17.00 No No 21 Less than 30 years of data 21 2002–2022 2.867 3.543
01364500 Esopus Creek At Mount Marion NY 419.00 Yes Yes — — — — — —
01364959 Rondout Cr Above Red Brook At Peekamoose NY 5.36 No No 13 Less than 30 years of data 13 1998–2010 1.482 1.722
01365000 Rondout Creek Near Lowes Corners NY 38.30 No No 85 Yes 30 1993–2022 7.397 9.446
01365500 Chestnut Creek At Grahamsville NY 20.90 No No 71 Yes 30 1981–1987, 2000–2022 3.590 4.221
01366500 Rondout Creek Near Lackawack NY 100.00 Yes Yes — — — — — —
01366650 Sandburg Creek At Ellenville NY 52.80 No No 19 Less than 30 years of data 19 1959–1977 7.003 8.474
01367500 Rondout Creek At Rosendale NY 383.00 Yes No 101 Yes 30 1993–2022 47.489 54.060
01367800 Papakating Creek At Pellettown NJ 15.80 No No 10 Less than 30 years of data 10 2005–2014 0.969 1.466
01368000 Wallkill River Near Unionville NY 140.00 Yes No 43 No 43 1939–1981 8.803 11.926
01368500 Rutgers Creek At Gardnerville NY 59.70 No No 22 Less than 30 years of data 22 1945–1954, 1957–1968 0.481 0.690
01369000 Pochuck Creek Near Pine Island NY 98.00 No No 39 No 39 1939–1977 3.672 5.101
01369500 Quaker Creek At Florida NY 9.74 No No 41 No 41 1939–1979 0.199 0.273
01370000 Wallkill River At Pellets Island NY 380.00 Yes No 48 No 48 1921–1968 13.337 18.656
01370500 Wallkill River Near Phillipsburg NY 415.00 No No 22 Less than 30 years of data 22 1938–1959 22.105 29.732
01371000 Shawangunk Kill At Pine Bush NY 104.00 Yes Yes — — — — — —
01371500 Wallkill River At Gardiner NY 695.00 Yes No 97 No 97 1926–2022 31.801 44.524
01372200 Wappinger Creek Near Clinton Corners NY 92.40 No No 19 Less than 30 years of data 19 1957–1975 3.390 4.891
01372300 Little Wappinger Creek At Salt Point NY 32.90 No No 19 Less than 30 years of data 19 1957–1975 0.366 0.549
01372500 Wappinger Creek Near Wappingers Falls NY 181.00 No No 93 No 93 1930–2022 6.581 9.245
01372800 Fishkill Creek At Hopewell Junction NY 57.30 No No 17 Less than 30 years of data 17 1959–1975 1.909 2.515
01373500 Fishkill Creek At Beacon NY 190.00 Yes Yes — — — — — —
0137449480 East Branch Croton River Near Putnam Lake NY 62.10 No No 26 Less than 30 years of data 26 1997–2022 0.314 0.933
01374505 East Branch Croton River At Brewster NY 81.20 Yes Yes — — — — — —
01374531 East Branch Croton River Near Croton Falls NY 86.40 Yes Yes — — — — — —
01374559 West Branch Croton River At Richardsville NY 11.00 No No 26 Less than 30 years of data 26 1997–2022 0.027 0.072
01374581 W Br Croton River Below Dam Near Kent Cliffs NY 22.40 Yes Yes — — — — — —
0137462010 West Branch Croton River Near Carmel NY 42.90 Yes Yes — — — — — —
01374654 Middle Branch Croton River Near Carmel NY 13.70 No No 17 Less than 30 years of data 17 1997–2013 0.450 0.869
01374701 West Branch Croton River Near Croton Falls NY 80.40 Yes Yes — — — — — —
01374781 Titicus River Below June Road At Salem Center NY 12.90 No No 15 Less than 30 years of data 15 2008–2022 0.387 0.723
01374821 Titicus River At Purdys Station NY 23.80 Yes No 27 Less than 30 years of data 27 1995–2002, 2004–2022 4.817 6.006
01374890 Cross River Near Cross River NY 17.10 No No 26 Less than 30 years of data 26 1997–2022 0.375 0.742
01374901 Cross River At Katonah NY 29.90 Yes Yes — — — — — —
01374930 Muscoot River At Baldwin Place NY 13.50 No No 26 Less than 30 years of data 26 1997–2022 0.215 0.515
01374941 Muscoot River Below Dam At Amawalk NY 19.70 Yes Yes — — — — — —
01374987 Kisco River Below Mount Kisco NY 17.60 No No 13 Less than 30 years of data 13 1997–2009 0.573 1.482
01375000 Croton R At New Croton Dam Nr Croton–On–Hudson NY 378.00 Yes Yes — — — — — —
01376500 Saw Mill River At Yonkers NY 25.60 Yes Yes — — — — — —
01376800 Hackensack River At West Nyack NY 30.70 Yes Yes — — — — — —
01377000 Hackensack River At Rivervale NJ 58.00 Yes Yes — — — — — —
01377370 Pascack Brook At Park Ridge NJ 13.40 No No 15 Less than 30 years of data 15 2005–2009, 2011–2020 2.896 3.917
01377500 Pascack Brook At Westwood NJ 29.60 Yes No 84 No 84 1936–1986, 1988–2020 9.586 12.802
01384000 Wanaque River At Monks NJ 40.40 Yes Yes — — — — — —
01386000 West Brook Near Wanaque NJ 11.80 Yes No 62 No 62 1936–1978, 2004–2022 0.635 0.948
01387000 Wanaque River At Wanaque NJ 90.40 Yes Yes — — — — — —
01387400 Ramapo River At Ramapo NY 86.90 No No 42 No 42 1981–2022 9.747 11.519
01387420 Ramapo River At Suffern NY 93.00 Yes Yes — — — — — —
01387450 Mahwah River Near Suffern NY 12.30 No No 52 No 52 1960–1995, 2007–2022 0.714 1.040
01387500 Ramapo River Near Mahwah NJ 120.00 Yes No 102 No 102 1904–1906, 1924–2022 11.134 15.116
01390450 Saddle River At Upper Saddle River NJ 10.90 Yes No 16 Less than 30 years of data 16 2005–2020 0.589 0.966
01390500 Saddle River At Ridgewood NJ 21.60 Yes No 63 No 63 1956–1974, 1979–2022 2.101 3.208
01391000 Hohokus Brook At Ho–Ho–Kus NJ 16.40 Yes Yes — — — — — —
01413398 Bush Kill Near Arkville NY 46.70 No No 24 Less than 30 years of data 24 1999–2022 5.125 6.473
01413408 Dry Brook At Arkville NY 82.20 No No 25 Less than 30 years of data 25 1998–2022 9.492 11.969
01413500 East Branch Delaware River At Margaretville NY 163.00 No No 85 Yes 30 1993–2022 13.491 17.346
01414000 Platte Kill At Dunraven NY 34.90 No No 45 Yes 30 1958–1962, 1998–2022 2.312 3.135
01414500 Mill Brook Near Dunraven NY 25.20 No No 85 Yes 30 1993–2022 2.435 3.124
01415000 Tremper Kill Near Andes NY 33.20 No No 85 No 85 1938–2022 1.597 2.434
01415500 Terry Clove Kill Near Pepacton NY 13.60 No No 25 Less than 30 years of data 25 1938–1962 0.341 0.636
01417000 East Branch Delaware River At Downsville NY 372.00 Yes Yes — — — — — —
01417500 East Branch Delaware River At Harvard NY 458.00 Yes Yes — — — — — —
01418000 Beaver Kill Near Turnwood NY 40.80 No No 10 Less than 30 years of data 10 1950–1959 5.996 8.561
01418500 Beaver Kill At Craigie Clair NY 81.90 No No 32 No 32 1939–1970 9.727 12.255
01419500 Willowemoc Creek Nr Livingston Manor NY 62.60 No No 35 No 35 1939–1970, 2020–2022 9.971 12.210
01420000 Little Beaver Kill Nr Livingston Manor NY 20.10 No No 56 No 56 1926–1981 1.947 2.629
01420500 Beaver Kill At Cooks Falls NY 241.00 No No 108 Yes 30 1993–2022 44.578 55.786
01421000 East Branch Delaware River At Fishs Eddy NY 784.00 Yes Yes — — — — — —
01421610 West Branch Delaware River At Hobart NY 16.00 No No 21 Less than 30 years of data 21 2002–2022 1.000 1.693
01421614 Town Brook Tributary Southeast Of Hobart NY 0.76 No No 10 Less than 30 years of data 10 2000–2009 0.044 0.067
01421618 Town Brook Southeast Of Hobart NY 14.30 No No 24 Less than 30 years of data 24 1999–2022 0.551 0.864
01421900 West Branch Delaware River Upstream From Delhi NY 134.00 No No 58 No 58 1938–1970, 1998–2022 7.581 9.737
01422500 Little Delaware River Near Delhi NY 49.80 No No 57 Yes 30 1966–1970, 1998–2022 2.597 4.110
01422747 East Brook East Of Walton NY 24.70 No No 18 Less than 30 years of data 18 2000–2013, 2019–2022 1.651 2.262
01423000 West Branch Delaware River At Walton NY 332.00 No No 71 No 71 1952–2022 23.749 29.473
01423500 Dryden Brook Near Granton NY 8.10 No No 14 Less than 30 years of data 14 1954–1967 0.362 0.544
0142400103 Trout Creek Near Trout Creek NY 20.20 No No 39 No 39 1954–1967, 1998–2022 0.396 0.585
01424500 Trout Creek At Cannonsville NY 49.50 No No 22 Less than 30 years of data 22 1942–1963 2.956 3.728
01425000 West Branch Delaware River At Stilesville NY 456.00 Yes Yes — — — — — —
01425675 Oquaga Creek Near North Sanford NY 4.69 No No 11 Less than 30 years of data 11 1971–1981 0.290 0.437
01426000 Oquaga Creek At Deposit NY 67.60 No No 32 No 32 1942–1973 1.611 2.479
01426500 West Branch Delaware River At Hale Eddy NY 595.00 Yes Yes — — — — — —
01427207 Delaware River At Lordville NY 1,590.00 Yes Yes — — — — — —
01427500 Callicoon Creek At Callicoon NY 110.00 No No 43 No 43 1942–1982, 2020–2021 6.528 8.653
01427510 Delaware River At Callicoon NY 1,820.00 Yes No 46 Yes 30 1993–2022 583.426 751.390
01428000 Tenmile River At Tusten NY 45.60 No No 29 Less than 30 years of data 29 1948–1973, 2020–2022 1.795 2.488
01428500 Delaware R Above Lackawaxen R Near Barryville NY 2,020.00 Yes No 81 Yes 30 1993–2022 687.612 890.065
01428750 West Branch Lackawaxen River Near Aldenville, PA 40.60 No No 35 No 35 1988–2022 5.661 6.981
01432900 Mongaup River At Mongaup Valley NY 76.60 No No 19 Less than 30 years of data 19 2004–2022 13.092 16.225
01433500 Mongaup River Near Mongaup NY 200.00 Yes Yes — — — — — —
01434000 Delaware River At Port Jervis NY 3,076.00 Yes Yes — — — — — —
0143400680 E Br Neversink R Northeast Of Denning NY 8.93 No No 24 Less than 30 years of data 24 1992–2013, 2021–2022 2.787 3.645
01434017 East Branch Neversink River Near Claryville NY 22.90 No No 30 No 30 1993–2022 7.067 9.129
01434021 W Br Neversink R At Winnisook L Nr Frost Valley NY 0.83 No No 24 Less than 30 years of data 24 1992–2013, 2021–2022 0.095 0.139
01434025 Biscuit Bk Above Pigeon Bk At Frost Valley NY 3.72 No No 38 No 38 1985–2022 0.457 0.691
01434092 Shelter Creek Below Dry Creek Nr Frost Valley NY 0.59 No No 14 Less than 30 years of data 14 1994–2007 0.056 0.092
01434498 West Branch Neversink River At Claryville NY 33.80 No No 29 Less than 30 years of data 29 1993–2021 8.517 10.893
01435500 Neversink River At Halls Mills Near Curry NY 68.70 No No 11 Less than 30 years of data 11 1939–1949 17.580 22.715
01436500 Neversink River At Woodbourne NY 113.00 Yes Yes — — — — — —
01436690 Neversink River At Bridgeville NY 171.00 Yes Yes — — — — — —
01437000 Neversink River At Oakland Valley NY 223.00 Yes Yes — — — — — —
01437500 Neversink River At Godeffroy NY 307.00 Yes Yes — — — — — —
01438500 Delaware River At Montague NJ 3,480.00 Yes Yes — — — — — —
01440000 Flat Brook Near Flatbrookville NJ 64.00 No No 97 No 97 1925–2021 7.540 9.442
01443500 Paulins Kill At Blairstown NJ 126.00 No No 99 No 99 1923–1977, 1979–2022 16.343 21.060
01496500 Oaks Creek At Index NY 102.00 Yes No 59 No 59 1931–1932, 1939–1995 3.732 4.887
01497500 Susquehanna R At Colliersville NY 349.00 Yes No 43 No 43 1926–1968 13.317 27.683
01498500 Charlotte Creek At West Davenport NY 167.00 No No 36 No 36 1940–1975 8.554 10.890
01499000 Otego Creek Near Oneonta NY 108.00 No No 27 Less than 30 years of data 27 1942–1968 6.885 8.549
01500000 Ouleout Creek At East Sidney NY 103.00 Yes No 81 Yes 30 1993–2022 7.229 8.401
01500500 Susquehanna River At Unadilla NY 982.00 Yes Yes — — — — — —
01501000 Unadilla River Near New Berlin NY 199.00 No No 43 No 43 1926–1968 14.588 18.185
01502000 Butternut Creek At Morris NY 59.70 No No 56 Yes 30 1966–1995 5.207 6.412
01502500 Unadilla River At Rockdale NY 520.00 No No 82 Yes 30 1987–1995, 2002–2022 64.261 79.476
01502632 Susquehanna River At Bainbridge NY 1,610.00 No No 12 Less than 30 years of data 12 2011–2022 253.877 309.436
01502731 Susquehanna River At Windsor NY 1,820.00 No No 12 Less than 30 years of data 12 2011–2022 295.366 351.082
01503000 Susquehanna River At Conklin NY 2,232.00 No No 109 Yes 30 1993–2022 210.092 253.168
01505000 Chenango River At Sherburne NY 263.00 Yes No 74 Yes 30 1984–1995, 2005–2022 29.062 35.161
01505500 Canasawacta Creek Near South Plymouth NY 57.90 No No 29 Less than 30 years of data 29 1947–1975 0.881 1.702
01505810 Chenango River At Oxford NY 458.00 Yes Yes — — — — — —
01507000 Chenango River At Greene NY 593.00 No No 45 No 45 1938–1970, 2011–2022 54.878 63.609
01507500 Genegantslet Cr At Smithville Flats NY 82.30 Yes No 31 No 31 1940–1970 1.847 2.405
01508000 Shackham Brook Near Truxton NY 3.16 No No 35 No 35 1934–1968 0.051 0.079
01508803 West Br Tioughnioga River At Homer NY 71.50 No No 14 Less than 30 years of data 14 1968–1968, 1974–1986 13.853 17.506
01509000 Tioughnioga River At Cortland NY 292.00 Yes No 83 Yes 30 1993–2022 43.386 49.876
01510000 Otselic River At Cincinnatus NY 147.00 No No 77 Yes 30 1993–2022 11.127 13.773
01510500 Otselic River Near Upper Lisle NY 217.00 No No 31 No 31 1939–1969 13.428 16.299
01511500 Tioughnioga River At Itaska NY 730.00 No No 37 No 37 1931–1967 57.595 73.398
01512500 Chenango River Near Chenango Forks NY 1,483.00 No No 109 Yes 30 1993–2022 143.387 174.897
01513500 Susquehanna River At Vestal NY 3,941.00 No No 40 No 40 1940–1967, 2011–2022 340.914 401.221
01513831 Susquehanna River At Owego NY 4,216.00 No No 12 Less than 30 years of data 12 2011–2022 560.713 742.825
01514000 Owego Creek Near Owego NY 185.00 No No 51 No 51 1932–1978, 2019–2022 10.462 11.535
01515000 Susquehanna River Near Waverly NY 4,773.00 No No 79 Yes 30 1987–1995, 2002–2022 491.840 633.581
01516350 Tioga River Near Mansfield, PA 153.00 No No 45 No 45 1978–2022 9.747 11.714
01518000 Tioga River At Tioga, PA 282.00 Yes No 83 Yes 30 1993–2022 24.728 25.377
01518500 Crooked Creek At Tioga, PA 122.00 No No 20 Less than 30 years of data 20 1955–1974 2.342 2.839
01518700 Tioga River At Tioga Junction, PA 446.00 Yes No 45 No 45 1978–2022 30.031 33.704
01518862 Cowanesque River At Westfield, PA 90.60 No No 38 No 38 1985–2022 1.458 2.318
01520500 Tioga River At Lindley NY 771.00 Yes Yes — — — — — —
01521500 Canisteo River At Arkport NY 30.60 Yes No 85 Yes 30 1993–2022 0.838 1.056
01523500 Canacadea Creek Near Hornell NY 57.90 Yes No 78 No 78 1942–1942, 1946–2022 3.262 5.934
01524500 Canisteo River Below Canacadea Creek At Hornell NY 158.00 Yes No 79 Yes 30 1993–2022 15.892 18.503
01525500 Canisteo River At West Cameron NY 340.00 Yes Yes — — — — — —
01525981 Tuscarora Creek Above South Addison NY 102.00 No No 21 Less than 30 years of data 21 2002–2022 0.163 0.411
01526500 Tioga River Near Erwins NY 1,377.00 Yes No 103 Yes 30 1993–2022 83.402 94.798
01527000 Cohocton River At Cohocton NY 52.20 No No 30 No 30 1952–1981 3.076 4.313
01527500 Cohocton River At Avoca NY 152.00 No No 26 Less than 30 years of data 26 1940–1945, 2003–2022 16.057 18.244
01528000 Fivemile Creek Near Kanona NY 66.80 No No 58 Yes 30 1966–1995 0.902 1.385
01529000 Mud Creek Near Savona NY 76.60 Yes No 45 No 45 1938–1982 0.727 1.098
01529500 Cohocton River Near Campbell NY 470.00 No No 103 Yes 30 1993–2022 28.631 36.629
01529950 Chemung River At Corning NY 2,006.00 Yes No 47 No 47 1976–2022 128.542 152.796
01530332 Chemung River At Elmira NY 2,162.00 Yes Yes — — — — — —
01530500 Newtown Creek At Elmira NY 77.50 Yes No 69 No 69 1940–2008 6.100 7.622
01531000 Chemung River At Chemung NY 2,506.00 Yes No 118 Yes 30 1993–2022 161.212 186.809
01531500 Susquehanna River At Towanda, PA 7,797.00 No No 108 Yes 30 1993–2022 676.552 810.977
03007800 Allegheny River At Port Allegany, PA 248.00 No No 47 No 47 1976–2022 14.023 20.420
03009680 Potato Creek At Smethport, PA 160.00 No No 20 Less than 30 years of data 20 1976–1995 14.162 17.622
03010000 Allegheny River At Larabee, PA 530.00 No No 13 Less than 30 years of data 13 1927–1939 13.733 25.247
03010500 Allegheny River At Eldred, PA 550.00 No No 82 No 82 1941–2022 31.965 44.540
03010655 Oswayo Creek At Shinglehouse, PA 98.70 No No 47 No 47 1976–2022 5.754 7.312
03010820 Allegheny River At Olean NY 1,168.00 No No 11 Less than 30 years of data 11 2012–2022 103.997 129.381
03011020 Allegheny River At Salamanca NY 1,608.00 No No 118 Yes 30 1993–2022 151.297 193.224
03011800 Kinzua Creek Near Guffey, PA 38.80 No No 56 No 56 1967–2022 5.211 6.561
03012550 Allegheny River At Kinzua Dam, PA 2,180.00 Yes Yes — — — — — —
03012600 Allegheny River At Warren, PA 2,223.00 Yes Yes — — — — — —
03013000 Conewango Creek At Waterboro NY 290.00 No No 54 Yes 30 1964–1993 34.859 39.968
03014500 Chadakoin River At Falconer NY 194.00 Yes Yes — — — — — —
03015000 Conewango Creek At Russell, PA 816.00 No No 82 Yes 30 1993–2022 105.940 122.171
03015310 Allegheny River Bl Conewango Creek At Warren, PA 3,131.00 Yes Yes — — — — — —
03015500 Brokenstraw Creek At Youngsville, PA 321.00 No No 112 Yes 30 1993–2022 43.869 50.737
03016000 Allegheny River At West Hickory, PA 3,660.00 Yes Yes — — — — — —
03021350 French Creek Near Wattsburg, PA 92.00 No No 47 No 47 1976–2022 5.110 8.360
03021410 West Branch French Creek Near Lowville, PA 52.30 No No 18 Less than 30 years of data 18 1976–1993 2.825 4.716
03021500 French Creek At Carters Corners, PA 208.00 No No 61 No 61 1911–1971 9.652 13.005
03021520 French Creek Near Union City, PA 221.00 No No 31 No 31 1973–1991, 2011–2022 19.516 28.688
03025500 Allegheny River At Franklin, PA 5,982.00 Yes Yes — — — — — —
04213500 Cattaraugus Creek At Gowanda NY 436.00 Yes Yes — — — — — —
04214500 Buffalo Creek At Gardenville NY 142.00 No No 77 Yes 30 1987–2007, 2014–2022 7.395 11.692
04215000 Cayuga Creek Near Lancaster NY 96.40 No No 76 Yes 30 1993–2022 0.756 2.444
04215500 Cazenovia Creek At Ebenezer NY 135.00 No No 81 Yes 30 1993–2022 7.084 12.288
04216000 Niagara River At Buffalo NY 263,700.00 Yes Yes — — — — — —
04216200 Scajaquada Creek At Buffalo NY 15.80 Yes Yes — — — — — —
04216418 Tonawanda Creek At Attica NY 76.90 No No 44 No 44 1979–2022 5.873 7.880
04216500 Little Tonawanda Creek At Linden NY 22.10 No No 69 No 69 1914–1968, 1979–1992 0.284 0.378
04217000 Tonawanda Creek At Batavia NY 171.00 No No 75 Yes 30 1991–1998, 2001–2022 7.104 10.933
04217500 Tonawanda Creek Near Alabama NY 231.00 No No 33 No 33 1957–1989 11.070 13.577
04217750 Murder Creek Near Akron NY 57.50 Yes Yes — — — — — —
04218000 Tonawanda Creek At Rapids NY 349.00 No No 51 No 51 1957–1965, 1981–2022 13.065 17.821
04218518 Ellicott Creek Below Williamsville NY 79.70 Yes Yes — — — — — —
04219768 Eighteenmile Creek At Burt NY 84.80 Yes Yes — — — — — —
04220045 Oak Orchard Creek Near Shelby NY 146.00 No No 13 Less than 30 years of data 13 2010–2022 0.513 2.041
04220250 West Creek Near Hilton NY 31.00 Yes Yes — — — — — —
0422026250 Northrup Creek At North Greece NY 10.10 Yes Yes — — — — — —
04221000 Genesee River At Wellsville NY 288.00 No No 51 No 51 1957–1958, 1974–2022 18.040 22.824
04221500 Genesee River At Scio NY 308.00 No No 55 No 55 1918–1972 13.583 17.599
04222000 Caneadea Creek At Caneadea NY 62.00 Yes Yes — — — — — —
04223000 Genesee River At Portageville NY 984.00 Yes No 113 Yes 30 1993–2022 72.242 92.659
04224775 Canaseraga Creek Above Dansville NY 88.90 No No 47 No 47 1976–2022 7.818 8.778
04225000 Canaseraga Creek Near Dansville NY 157.00 No No 53 No 53 1912–1912, 1922–1968, 1972–1976 14.366 17.379
04225500 Canaseraga Creek At Groveland NY 185.00 No No 11 Less than 30 years of data 11 1917–1919, 1957–1964 18.017 20.448
04226000 Keshequa Cr At Craig Colony At Sonyea NY 68.30 No No 21 Less than 30 years of data 21 1919–1932, 1976–1977, 2018–2022 0.834 1.456
04227000 Canaseraga Creek At Shakers Crossing NY 335.00 No No 58 Yes 30 1993–2022 27.952 34.252
04227500 Genesee River Near Mount Morris NY 1,424.00 Yes No 111 Yes 30 1993–2022 103.165 131.183
04227995 Conesus Creek Near Lakeville NY 72.00 Yes Yes — — — — — —
04228500 Genesee River At Avon NY 1,680.00 Yes No 66 Yes 30 1993–2022 132.949 159.731
04230380 Oatka Creek At Warsaw NY 39.50 No No 58 Yes 30 1993–2022 2.680 3.651
04230500 Oatka Creek At Garbutt NY 205.00 No No 76 Yes 30 1993–2022 24.674 25.887
04231000 Black Creek At Churchville NY 130.00 No No 76 Yes 30 1993–2022 1.300 3.032
04231600 Genesee River At Ford Street Bridge, Rochester NY 2,474.00 Yes Yes — — — — — —
04232000 Genesee River At Rochester NY 2,482.00 Yes Yes — — — — — —
04232034 Irondequoit Cr At Railroad Mills Near Fishers NY 39.20 No No 24 Less than 30 years of data 24 1993–2010, 2017–2022 9.027 10.414
04232040 Irondequoit Creek Near Pittsford NY 44.40 No No 11 Less than 30 years of data 11 1981–1991 9.807 11.824
04232047 Irondequoit Cr @ Linden Ave., E Rochester NY 101.00 Yes Yes — — — — — —
0423204920 East Branch Allen Creek At Pittsford NY 9.50 Yes No 11 Less than 30 years of data 11 1992–2002 0.801 1.247
04232050 Allen Creek Near Rochester NY 28.90 Yes No 62 Yes 30 1993–2022 3.151 5.407
0423205010 Irondequoit Cr Above Blossom Rd Near Rochester NY 142.00 Yes Yes — — — — — —
0423205025 Irondequoit Creek At Empire Blvd, Rochester NY 151.00 No No 11 Less than 30 years of data 11 1992–2002 29.581 38.391
04232100 Sterling Creek At Sterling NY 45.90 No No 38 Yes 30 1967–1995, 2019–2019 1.165 1.825
04232482 Keuka Lake Outlet At Dresden NY 207.00 Yes No 55 No 55 1966–2012, 2014–2021 9.121 12.184
04232650 Seneca River At Lock 4, Waterloo, NY 742.00 Yes Yes — — — — — —
04232730 Seneca River Near Seneca Falls NY 785.00 Yes Yes — — — — — —
04233000 Cayuga Inlet Near Ithaca NY 35.20 No No 75 No 75 1938–2012 2.827 3.513
04233286 Sixmile Creek At Brooktondale NY 27.00 No No 19 Less than 30 years of data 19 2004–2022 3.527 4.332
04233300 Sixmile Creek At Bethel Grove NY 39.00 No No 27 Less than 30 years of data 27 1996–2022 3.435 4.458
04234000 Fall Creek Near Ithaca NY 126.00 Yes No 97 Yes 30 1993–2022 9.795 14.428
0423401815 Salmon Creek Near Ludlowville NY 87.70 No No 11 Less than 30 years of data 11 2008–2009, 2014–2022 0.803 1.383
04234232 Great Brook Below Victor NY 16.80 No No 10 Less than 30 years of data 10 1995–2004 0.904 1.111
04235000 Canandaigua Outlet At Chapin NY 195.00 Yes Yes — — — — — —
04235150 Flint Creek At Potter NY 31.00 No No 11 Less than 30 years of data 11 1965–1968, 1972–1978 0.049 0.154
04235271 Clyde River At Lock 26 Nr Clyde NY 845.00 Yes No 31 No 31 1936–1966 31.472 67.358
04235299 Owasco Inlet Below Aurora Street At Moravia NY 106.00 No No 20 Less than 30 years of data 20 1961–1968, 2011–2022 5.790 7.287
04235440 Owasco Outlet At Genesee St., Auburn NY 204.00 Yes Yes — — — — — —
04235500 Owasco Outlet Near Auburn NY 206.00 Yes Yes — — — — — —
04235600 Seneca River (Erie Canal) Near Port Byron NY 2,815.00 Yes Yes — — — — — —
04236500 Skaneateles Creek At Willow Glen NY 75.80 Yes Yes — — — — — —
04237496 Seneca River Near Baldwinsville NY 3,130.00 Yes Yes — — — — — —
04237946 Onondaga Cr Trib 6 Blw Mudboil Area At Tully NY 0.32 Yes No 19 Less than 30 years of data 19 1993–2011 0.148 0.220
04237962 Onondaga Creek Near Cardiff NY 35.30 No No 15 Less than 30 years of data 15 2003–2017 5.146 6.353
04239000 Onondaga Creek At Dorwin Avenue, Syracuse NY 88.50 Yes No 68 Yes 30 1991–2020 15.603 19.258
04240010 Onondaga Creek At Spencer Street, Syracuse NY 110.00 Yes No 51 No 51 1972–2022 30.944 36.114
04240100 Harbor Brook At Syracuse NY 10.00 Yes Yes — — — — — —
04240105 Harbor Brook At Hiawatha Boulevard, Syracuse NY 12.10 Yes Yes — — — — — —
04240120 Ley Creek At Park Street, Syracuse NY 29.90 Yes No 47 No 47 1974–2020 4.835 7.637
04240180 Ninemile Creek Near Marietta NY 45.10 Yes No 48 Yes 30 1984–2013 1.718 2.588
04240200 Ninemile Creek At Camillus NY 84.30 Yes Yes — — — — — —
04240300 Ninemile Creek At Lakeland NY 115.00 Yes Yes — — — — — —
04242500 East Branch Fish Creek At Taberg NY 188.00 Yes No 85 Yes 30 1979–1995, 2010–2022 35.382 46.872
04243500 Oneida Creek At Oneida NY 113.00 No No 72 Yes 30 1993–2022 17.745 22.220
04244000 Chittenango Creek Near Chittenango NY 66.30 Yes No 24 Less than 30 years of data 24 1952–1968, 2016–2022 12.433 14.873
04245000 Limestone Creek At Fayetteville NY 85.50 Yes No 46 No 46 1941–1986 17.210 19.874
04245200 Butternut Creek Near Jamesville NY 32.20 No No 40 No 40 1960–1999 4.131 4.939
04245236 Meadow Brook At Hurlburt Rd, Syracuse NY 2.94 Yes Yes — — — — — —
04246500 Oneida River At Caughdenoy NY 1,382.00 Yes Yes — — — — — —
04247000 Oneida River Near Euclid NY 1,439.00 Yes Yes — — — — — —
04247055 Oswego River Near Phoenix NY 4,953.00 Yes Yes — — — — — —
04249000 Oswego River At Lock 7, Oswego NY 5,100.00 Yes Yes — — — — — —
04250200 Salmon River At Pineville NY 238.00 Yes Yes — — — — — —
04250750 Sandy Creek Near Adams NY 137.00 No No 56 Yes 30 1985–1995, 2004–2022 4.333 6.574
04252500 Black River Near Boonville NY 284.00 Yes No 111 Yes 30 1993–2022 101.409 142.394
04253296 Buck Creek Near Inlet NY 1.16 No No 22 Less than 30 years of data 22 1990–1990, 2002–2022 0.039 0.112
04253500 Middle Branch Moose River At Old Forge NY 55.00 Yes Yes — — — — — —
04254000 Middle Branch Moose River Near Mckeever NY 151.00 Yes No 42 Yes 30 1939–1968 41.048 50.771
04254500 Moose River At Mckeever NY 363.00 No No 60 Yes 30 1941–1970 97.272 119.089
04255500 Independence River At Sperryville NY 81.80 No No 12 Less than 30 years of data 12 1930–1941 15.087 17.776
04256000 Independence River At Donnattsburg NY 88.70 No No 79 Yes 30 1993–2022 22.431 30.976
04258000 Beaver River At Croghan NY 291.00 Yes No 86 No 86 1932–1946, 1948–1981, 1983–1992, 1994–1995, 1997–2012, 2014–2022 163.256 227.654
04258500 Deer River At Copenhagen NY 89.00 No No 26 Less than 30 years of data 26 1931–1956 2.042 4.046
04258700 Deer River At Deer River NY 97.20 No No 11 Less than 30 years of data 11 1958–1968 2.740 7.266
04260500 Black River At Watertown NY 1,864.00 Yes No 101 Yes 30 1993–2022 847.982 1,049.977
04261000 Oswegatchie River At Cranberry Lake NY 140.00 Yes Yes — — — — — —
04262000 Oswegatchie River Near Oswegatchie NY 259.00 Yes No 77 Yes 30 1993–2022 92.542 124.340
04262500 West Branch Oswegatchie River Near Harrisville NY 258.00 Yes No 105 Yes 30 1993–2022 47.884 60.894
04263000 Oswegatchie River Near Heuvelton NY 986.00 Yes No 105 No 105 1918–2022 220.078 278.091
04264331 Saint Lawrence R At Cornwall Ont Nr Massena NY 298,800.00 Yes Yes — — — — — —
04265000 Grass River At Pyrites NY 333.00 No No 52 Yes 30 1948–1977 77.546 102.912
04265432 Grass River At Chase Mills NY 598.00 No No 18 Less than 30 years of data 18 2005–2022 88.213 118.736
04266500 Raquette River At Piercefield NY 721.00 Yes No 111 No 111 1910–1940, 1942–1958, 1960–2022 84.876 163.451
04267500 Raquette River At South Colton NY 937.00 Yes Yes — — — — — —
04268000 Raquette River At Raymondville NY 1,125.00 Yes No 76 No 76 1945–2005, 2008–2022 325.378 468.665
04268800 West Branch St. Regis River Near Parishville NY 171.00 No No 38 No 38 1960–1968, 1993–2015, 2017–2022 52.811 65.477
04269000 St. Regis River At Brasher Center NY 612.00 No No 106 No 106 1912–1917, 1921–1996, 1999–2022 157.522 193.129
04269500 Deer River At Brasher Iron Works NY 191.00 No No 12 Less than 30 years of data 12 1914–1916, 1960–1968 30.986 35.725
04270000 Salmon River At Chasm Falls NY 132.00 Yes No 82 Yes 30 1979–1982, 1988–2013 82.979 100.504
04270200 Little Salmon River At Bombay NY 89.70 No No 56 No 56 1959–1995, 2004–2022 14.102 18.757
04270500 Chateaugay River Near Chateaugay NY 112.00 Yes No 36 No 36 1928–1931, 1933–1940, 1942–1965 45.361 54.029
04270510 Chateaugay River Below Chateaugay NY 151.00 Yes No 29 Less than 30 years of data 29 1967–1995 56.881 64.014
04271500 Great Chazy River At Perry Mills NY 243.00 Yes No 70 No 70 1930–1968, 1991–2015, 2017–2022 18.049 25.137
04271815 Little Chazy River Near Chazy NY 50.30 No No 30 No 30 1991–2014, 2017–2022 0.996 1.460
04273000 Saranac River At Saranac NY 521.00 No No 12 Less than 30 years of data 12 1932–1943 147.731 168.782
04273500 Saranac River At Plattsburgh NY 608.00 Yes Yes — — — — — —
04273700 Salmon River At South Plattsburgh NY 63.30 No No 39 Yes 30 1992–2014, 2016–2022 9.956 12.170
04273800 Little Ausable River Near Valcour NY 67.80 No No 30 No 30 1993–2022 3.755 6.256
04274000 W Br Ausable R Nr Lake Placid NY 116.00 Yes Yes — — — — — —
04274500 Black Brook At Black Brook NY 49.40 Yes No 36 Yes 30 1932–1961 4.423 7.381
04275000 East Branch Ausable River At Au Sable Forks NY 198.00 Yes No 76 Yes 30 1972–1995, 2017–2022 39.754 53.524
04275500 Ausable River Near Au Sable Forks NY 446.00 Yes No 87 No 87 1912–1917, 1919–1968, 1991–2015, 2017–2022 104.403 126.144
04276500 Boquet River At Willsboro NY 270.00 Yes No 75 No 75 1925–1968, 1991–2014, 2016–2022 31.260 38.643
04276842 Putnam Creek East Of Crown Point Center NY 51.60 No No 25 Less than 30 years of data 25 1991–2014, 2019–2019 1.036 1.809
04278300 Northwest Bay Brook Near Bolton Landing NY 22.00 No No 27 Less than 30 years of data 27 1967–1968, 1973–1997 0.655 1.007
04279000 La Chute At Ticonderoga NY 234.00 Yes Yes — — — — — —
04280000 Poultney River Below Fair Haven, VT 187.00 Yes No 93 No 93 1930–2022 8.545 12.200
04280350 Mettawee River Near Pawlet, VT 70.20 No No 24 Less than 30 years of data 24 1986–2009 8.612 11.456
04280450 Mettawee River Near Middle Granville NY 167.00 No No 32 No 32 1991–2022 12.594 16.946
04292500 Lamoille River At East Georgia, VT 686.00 No No 92 No 92 1931–2022 154.865 201.542
04292700 Stone Bridge Brook Near Georgia Plains, VT 8.45 No No 21 Less than 30 years of data 21 1964–1974, 1991–2000 0.338 0.674
Table 1.1.    Low-streamflow statistics for the lowest annual 7-day and 30-day average streamflow that occurs (on average) once every 10 years (7Q10 or 30Q10, respectively) for 213 unaltered and 79 altered gages.

References Cited

Stagnitta, T.J., Graziano, A.P., Woda, J.C., Glas, R.L., and Gazoorian, C.L., 2024, Low-flow statistics for New York State, excluding Long Island, computed through March 2022: U.S. Geological Survey data release, https://doi.org/10.5066/P9NOM6FR.

U.S. Geological Survey, 2016, USGS water data for the nation: U.S. Geological Survey National Water Information System data system, accessed December 19, 2023, at https://doi.org/10.5066/F7P55KJN.

Conversion Factors

U.S. customary units to International System of Units

Multiply By To obtain
square mile (mi2) 2.590 square kilometer (km2)
cubic foot per second (ft3/s) 0.02832 cubic meter per second (m3/s)

Datum

Horizontal coordinate information is referenced to the North American Datum of 1983 (NAD 83).

Abbreviations

α

statistical significance level

30Q10

the lowest annual 30-day average streamflow that occurs (on average) once every 10 years

7Q10

the lowest annual 7-day average streamflow that occurs (on average) once every 10 years

NWIS

National Water Information System

NYSDEC

New York State Department of Environmental Conservation

USGS

U.S. Geological Survey

For more information, contact

Director, New York Water Science Center

U.S. Geological Survey

425 Jordan Road

Troy, NY 12180–8349

dc_ny@usgs.gov

or visit our website at

https://www.usgs.gov/centers/ny-water

Publishing support provided by the Pembroke Publishing Service Center

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Suggested Citation

Stagnitta, T.J., Graziano, A.P., Woda, J.C., Glas, R.L., and Gazoorian, C.L., 2024, Low-flow statistics for selected streams in New York, excluding Long Island: U.S. Geological Survey Scientific Investigations Report 2024–5055, 39 p., https://doi.org/10.3133/sir20245055.

ISSN: 2328-0328 (online)

Publication type Report
Publication Subtype USGS Numbered Series
Title Low-flow statistics for selected streams in New York, excluding Long Island
Series title Scientific Investigations Report
Series number 2024-5055
DOI 10.3133/sir20245055
Year Published 2024
Language English
Publisher U.S. Geological Survey
Publisher location Reston, VA
Contributing office(s) New York Water Science Center
Description Report: vi, 39 p.; Data release
Online Only (Y/N) Y
Additional Online Files (Y/N) N
Google Analytic Metrics Metrics page
Additional publication details